Introduction
Air quality in the US varies by state. According to data from the table below, Hawaii has the best air quality with 99.40% of good air quality days, followed by Maine with 93.20% and Alaska with 92.30%. On the other hand, California has the worst air quality with only 60.60% of good air quality days, followed by Arizona with 64.60%.
States with the best air quality tend to be in the Northeast and Northwest regions, while states with the worst air quality tend to be in the Southwest region. Additionally, states with larger populations and higher levels of industrialization tend to have worse air quality. This could be due to higher levels of pollution from transportation and industry. However, it is worth noting that some states, such as Texas and Florida, have large populations and industries but still have relatively good air quality.
Air Quality by State Ranking
# | State | Good Air Quality Days | Moderate Air Quality Days | Unhealthy Air Quality Days |
---|---|---|---|---|
1 | Hawaii | 99.4% | 0.6% | 0% |
2 | Maine | 93.2% | 6.3% | 0.5% |
3 | Alaska | 92.3% | 6.4% | 1.3% |
4 | Virginia | 91.5% | 8.4% | 0.2% |
5 | Vermont | 91.3% | 8.5% | 0.2% |
6 | New Hampshire | 91% | 8.5% | 0.5% |
7 | Florida | 89.8% | 10.2% | 0% |
8 | New York | 88.7% | 10.6% | 0.6% |
9 | Washington | 88.7% | 9.7% | 1.6% |
10 | Louisiana | 87.9% | 11.9% | 0.2% |
11 | Massachusetts | 87.1% | 12.5% | 0.5% |
12 | Nebraska | 86.8% | 12.6% | 0.5% |
13 | Rhode Island | 86.7% | 12.4% | 0.8% |
14 | West Virginia | 86.7% | 13.2% | 0% |
15 | North Carolina | 86.3% | 13.7% | 0.1% |
16 | Missouri | 86.1% | 13.4% | 0.4% |
17 | Alabama | 85.8% | 14% | 0.2% |
18 | Mississippi | 85.5% | 14.5% | 0% |
19 | Kentucky | 85.2% | 14.6% | 0.2% |
20 | South Carolina | 84.9% | 15.1% | 0.1% |
21 | Tennessee | 84.5% | 15.2% | 0.3% |
22 | Maryland | 84.2% | 15.1% | 0.7% |
23 | Connecticut | 83.4% | 14.3% | 2.3% |
24 | Minnesota | 83.4% | 15.4% | 1.2% |
25 | Arkansas | 83% | 16.8% | 0.2% |
26 | Oregon | 83% | 14.1% | 2.9% |
27 | New Jersey | 82.3% | 16.9% | 0.8% |
28 | Georgia | 82.1% | 17.5% | 0.4% |
29 | South Dakota | 82.1% | 16.6% | 1.3% |
30 | North Dakota | 81.1% | 15.8% | 3.2% |
31 | Indiana | 80.9% | 18.8% | 0.3% |
32 | Ohio | 80.9% | 18.8% | 0.3% |
33 | Kansas | 80.8% | 18.3% | 0.9% |
34 | Montana | 80.8% | 15.9% | 3.3% |
35 | Texas | 80.5% | 18.5% | 1% |
36 | Delaware | 80.3% | 19% | 0.7% |
37 | Michigan | 79.9% | 19.4% | 0.7% |
38 | Wisconsin | 79.8% | 19.3% | 0.9% |
39 | Pennsylvania | 79.2% | 20.2% | 0.6% |
40 | Idaho | 79% | 18.1% | 2.9% |
41 | New Mexico | 78.9% | 19.3% | 1.7% |
42 | Wyoming | 78.9% | 19.3% | 1.8% |
43 | Iowa | 78.3% | 21.3% | 0.4% |
44 | Oklahoma | 76.7% | 22.2% | 1.1% |
45 | Colorado | 75.4% | 20.9% | 3.7% |
46 | Illinois | 75% | 24.3% | 0.8% |
47 | Nevada | 72.5% | 22.8% | 4.7% |
48 | Utah | 70.2% | 26.6% | 3.2% |
49 | District of Columbia | 69% | 28.8% | 2.2% |
50 | Arizona | 64.6% | 28.9% | 6.5% |
51 | California | 60.6% | 31.1% | 8.4% |
States With the Best Air Quality
The ten states with the best air quality are Hawaii, Maine, Alaska, Virginia, Vermont, New Hampshire, Florida, New York, Washington, and Louisiana. Hawaii has the best air quality in the US with 99.40% of good air quality days. Maine is the second state with the best air quality with 93.20% good air quality days. Alaska comes in third place with 92.30% of good air quality days. Virginia has the fourth best air quality in the US with 91.50% of good air quality days, while Vermont comes in fifth place with 91.30% of good air quality days. New Hampshire has the sixth best air quality in the US with 91% of good air quality days, and Florida follows with 89.80% of good air quality days. New York is the eighth state with the best air quality with 88.70% of good air quality days, while Washington comes in ninth place with 88.70% of good air quality days. Finally, Louisiana is the tenth state with the best air quality in the US with 87.90% of good air quality days.
The ten states with the best air quality are:
1. Hawaii – 99.40%
2. Maine – 93.20%
3. Alaska – 92.30%
4. Virginia – 91.50%
5. Vermont – 91.30%
6. New Hampshire – 91%
7. Florida – 89.80%
8. New York – 88.70%
9. Washington – 88.70%
10. Louisiana – 87.90%
Best Air Quality in US
Hawaii has the best air quality in the US with 99.40% of good air quality days, and there are several factors that contribute to this. First of all, Hawaii’s remote location in the middle of the Pacific Ocean means that there are fewer sources of pollution from industrial activities and transportation. Additionally, the state has a relatively small population and a low density of vehicles, which also helps to minimize pollution. The islands’ strong trade winds also blow pollution away from the islands, helping to keep the air clean. Finally, Hawaii’s commitment to renewable energy, such as wind and solar power, has reduced the reliance on fossil fuels and further improved air quality. Overall, these factors have contributed to Hawaii having the best air quality in the US.
Most Polluted States in the US
The ten most polluted states in the US are California, Arizona, the District of Columbia, Utah, Nevada, Illinois, Colorado, Oklahoma, Iowa, and Wyoming. California has the worst air quality in the US with only 60.60% of good air quality days. Arizona is the second most polluted state in the US with 64.60% good air quality days. The District of Columbia has the third worst air quality in the US with 69% of good air quality days, while Utah comes in fourth place with 70.20% of good air quality days. Nevada is the fifth most polluted state in the US with 72.50% of good air quality days. Illinois has a 75% of good air quality days, followed by Colorado with 75.40%. Oklahoma is the eighth most polluted state with 76.70% of good air quality days. Iowa has the ninth worst air quality with 78.30% of good air quality days. Finally, Wyoming is the tenth most polluted state with 78.90% of good air quality days.
The ten most polluted states in the US are:
1. California – 60.60%
2. Arizona – 64.60%
3. District of Columbia – 69%
4. Utah – 70.20%
5. Nevada – 72.50%
6. Illinois – 75%
7. Colorado – 75.40%
8. Oklahoma – 76.70%
9. Iowa – 78.30%
10. Wyoming – 78.90%
Worst Air Quality in US
California has the worst air quality in the US with 60.60% of good air quality days due to a combination of factors. Firstly, the state’s geography contributes to trapping air pollutants, particularly in the Central Valley, where the San Joaquin Valley sees heavy agricultural and industrial activity. Secondly, California’s high population density means there are more sources of pollution, such as transportation emissions, industrial plants, and household activities. Thirdly, the state’s warm climate and frequent wildfires worsen air quality, as wildfires release particulate matter and other harmful pollutants into the air. These factors make it difficult for California to maintain good air quality and prevent it from ranking as the most polluted state in the US.
States Ranked by Air Quality
Alabama
Good Air Quality Days
85.8%
Ranked in the US
#17
Moderate Air Quality Days
14%
Ranked in the US
#35
Unhealthy Air Quality Days
0.2%
Ranked in the US
#7
Alabama has 85.80% of days with good air quality, 0.20% of days with unhealthy air quality, and 14% of days with moderate air quality. Alabama has good air quality overall, with most of its days being classified as good.
Alaska
Good Air Quality Days
92.3%
Ranked in the US
#3
Moderate Air Quality Days
6.4%
Ranked in the US
#50
Unhealthy Air Quality Days
1.3%
Ranked in the US
#37
Alaska has the third best air quality in the US with 92.30% of good air quality days, 1.30% of unhealthy air quality days, and 6.40% of moderate air quality days. Alaska's remote location and low population density help to keep its air quality clean.
Arizona
Good Air Quality Days
64.6%
Ranked in the US
#50
Moderate Air Quality Days
28.9%
Ranked in the US
#2
Unhealthy Air Quality Days
6.5%
Ranked in the US
#51
Arizona has the second worst air quality in the US with 64.60% good air quality days. There are 6.50% unhealthy air quality days and 28.90% moderate air quality days. Arizona's air quality issues are due to its location in a desert climate, which allows for the accumulation of air pollutants, and also its urbanization and population growth. Additionally, the state's topography and climate make it prone to dust storms, which can exacerbate air quality issues.
Arkansas
Good Air Quality Days
83%
Ranked in the US
#25
Moderate Air Quality Days
16.8%
Ranked in the US
#23
Unhealthy Air Quality Days
0.2%
Ranked in the US
#8
Arkansas has a good air quality rating of 83%, with moderate air quality making up 16.8%, and unhealthy air quality making up 0.2% of the days. The state's air quality is generally good due to its rural character and low population density. However, pollution from coal-fired power plants and agriculture can impact air quality in certain areas, particularly during the summer months.
California
Good Air Quality Days
60.6%
Ranked in the US
#51
Moderate Air Quality Days
31.1%
Ranked in the US
#1
Unhealthy Air Quality Days
8.4%
Ranked in the US
#52
California has the worst air quality in the US with only 60.60% of good air quality days. In addition, 8.40% of days have unhealthy air quality, and 31.10% have moderate air quality. California's poor air quality is primarily due to its large population, heavy traffic, and industrialization. California also experiences wildfires frequently, which worsen the air quality by releasing smoke and particulate matter into the atmosphere.
Colorado
Good Air Quality Days
75.4%
Ranked in the US
#45
Moderate Air Quality Days
20.9%
Ranked in the US
#9
Unhealthy Air Quality Days
3.7%
Ranked in the US
#49
Colorado has the seventh worst air quality in the US with 75.40% good air quality days, 3.70% unhealthy air quality days, and 20.90% moderate air quality days. Colorado's geography contributes to poor air quality, as the state is situated in a valley, which can trap air pollutants. The state's growing population and increase in oil and gas production have also contributed to poor air quality.
Connecticut
Good Air Quality Days
83.4%
Ranked in the US
#23
Moderate Air Quality Days
14.3%
Ranked in the US
#33
Unhealthy Air Quality Days
2.3%
Ranked in the US
#43
Connecticut has a good air quality rating of 83.4%, with moderate air quality making up 14.3%, and unhealthy air quality making up 2.3% of the days. The state's air quality is impacted by a variety of factors, including transportation, power plants, and industrial sources. While Connecticut has taken steps to reduce emissions and improve air quality, it still struggles with ozone and particulate matter pollution in urban areas.
Delaware
Good Air Quality Days
80.3%
Ranked in the US
#36
Moderate Air Quality Days
19%
Ranked in the US
#15
Unhealthy Air Quality Days
0.7%
Ranked in the US
#25
Delaware has a good air quality record, with 80.3% of days classified as good air quality days. The state has a low percentage of unhealthy air quality days at 0.7% and a moderate percentage of moderate air quality days at 19%. Delaware has a relatively small population and a low number of industrial facilities, which contributes to its good air quality. However, the state is located on the east coast, where it can be affected by air pollution transported from other states and countries.
District of Columbia
Good Air Quality Days
69%
Ranked in the US
#49
Moderate Air Quality Days
28.8%
Ranked in the US
#3
Unhealthy Air Quality Days
2.2%
Ranked in the US
#42
The District of Columbia has the third worst air quality in the US with 69% good air quality days, 2.20% unhealthy air quality days, and 28.80% moderate air quality days. The city's air pollution comes from various sources, including emissions from vehicles, industrial facilities, and power plants. The high population density in the area also contributes to the poor air quality.
Florida
Good Air Quality Days
89.8%
Ranked in the US
#7
Moderate Air Quality Days
10.2%
Ranked in the US
#45
Unhealthy Air Quality Days
0%
Ranked in the US
#1
Florida has the seventh best air quality in the US with 89.80% of good air quality days, 0% of unhealthy air quality days, and 10.20% of moderate air quality days. Florida's ocean breezes and relatively low levels of industrial activity help to maintain its air quality.
Georgia
Good Air Quality Days
82.1%
Ranked in the US
#28
Moderate Air Quality Days
17.5%
Ranked in the US
#21
Unhealthy Air Quality Days
0.4%
Ranked in the US
#16
Georgia has a good air quality rating of 82.1%, with moderate air quality making up 17.5%, and unhealthy air quality making up 0.4% of the days. The state's air quality has improved in recent years due to efforts to reduce emissions from transportation and industry. However, Georgia still faces challenges with air pollution, particularly in urban areas, where transportation and industry contribute to poor air quality.
Hawaii
Good Air Quality Days
99.4%
Ranked in the US
#1
Moderate Air Quality Days
0.6%
Ranked in the US
#52
Unhealthy Air Quality Days
0%
Ranked in the US
#2
Hawaii has the best air quality in the US with 99.40% of good air quality days, only 0% of unhealthy air quality days, and 0.60% of moderate air quality days. Hawaii has consistently good air quality due to its isolation in the middle of the Pacific Ocean, which helps to prevent pollutants from reaching the islands.
Idaho
Good Air Quality Days
79%
Ranked in the US
#40
Moderate Air Quality Days
18.1%
Ranked in the US
#20
Unhealthy Air Quality Days
2.9%
Ranked in the US
#44
Idaho has a relatively good air quality record, with 79% of days having good air quality. However, the state experienced 2.9% of days with unhealthy air quality, and 18.1% of days were moderate. Forest fires, dust, and vehicle emissions contribute to Idaho's air pollution. Additionally, the state's geographic location means that pollution from other states can affect its air quality.
Illinois
Good Air Quality Days
75%
Ranked in the US
#46
Moderate Air Quality Days
24.3%
Ranked in the US
#5
Unhealthy Air Quality Days
0.8%
Ranked in the US
#29
Illinois has the sixth worst air quality in the US with 75% good air quality days, 0.80% unhealthy air quality days, and 24.30% moderate air quality days. Illinois's air pollution comes from a combination of industrial sources, such as power plants and factories, and transportation sources, including cars and trucks. The state's position in the Midwest also contributes to its poor air quality, as it is subject to emissions from surrounding states.
Indiana
Good Air Quality Days
80.9%
Ranked in the US
#31
Moderate Air Quality Days
18.8%
Ranked in the US
#16
Unhealthy Air Quality Days
0.3%
Ranked in the US
#13
Indiana has a good air quality rating of 80.9%, with moderate air quality making up 18.8%, and unhealthy air quality making up 0.3% of the days. The state's air quality has improved in recent years due to efforts to reduce emissions from transportation and industry. However, Indiana still faces challenges with air pollution, particularly in urban areas, where transportation and industry contribute to poor air quality.
Iowa
Good Air Quality Days
78.3%
Ranked in the US
#43
Moderate Air Quality Days
21.3%
Ranked in the US
#8
Unhealthy Air Quality Days
0.4%
Ranked in the US
#17
Iowa has the ninth worst air quality in the US with 78.30% good air quality days, 0.40% unhealthy air quality days, and 21.30% moderate air quality days. Iowa's air pollution primarily comes from agricultural sources, including livestock production and fertilizer application.
Kansas
Good Air Quality Days
80.8%
Ranked in the US
#33
Moderate Air Quality Days
18.3%
Ranked in the US
#19
Unhealthy Air Quality Days
0.9%
Ranked in the US
#32
Kansas has a good air quality record, with 80.8% of days classified as good air quality days. The state has a relatively low percentage of moderate air quality days at 0.9% and unhealthy air quality days at 18.3%. However, the state experiences some episodes of poor air quality caused by dust storms, wildfires, and agricultural activities. These events can release large amounts of particulate matter and other air pollutants into the atmosphere, leading to decreased air quality.
Kentucky
Good Air Quality Days
85.2%
Ranked in the US
#19
Moderate Air Quality Days
14.6%
Ranked in the US
#31
Unhealthy Air Quality Days
0.2%
Ranked in the US
#9
Kentucky has 85.20% of days with good air quality, 0.20% of days with unhealthy air quality, and 14.60% of days with moderate air quality. Kentucky has good air quality overall, with most of its days being classified as good.
Louisiana
Good Air Quality Days
87.9%
Ranked in the US
#10
Moderate Air Quality Days
11.9%
Ranked in the US
#43
Unhealthy Air Quality Days
0.2%
Ranked in the US
#10
Louisiana has the tenth best air quality in the US with 87.90% of good air quality days, 0.20% of unhealthy air quality days, and 11.90% of moderate air quality days. Louisiana's high levels of industrial activity and location along the Gulf of Mexico can lead to poor air quality at times, but the state has made significant progress in reducing its air pollution levels in recent years.
Maine
Good Air Quality Days
93.2%
Ranked in the US
#2
Moderate Air Quality Days
6.3%
Ranked in the US
#51
Unhealthy Air Quality Days
0.5%
Ranked in the US
#19
Maine has the second best air quality in the US, with 93.20% of good air quality days, 0.50% of unhealthy air quality days, and 6.30% of moderate air quality days. Maine's relatively low population density and location in the northeastern US help to maintain its clean air quality.
Maryland
Good Air Quality Days
84.2%
Ranked in the US
#22
Moderate Air Quality Days
15.1%
Ranked in the US
#29
Unhealthy Air Quality Days
0.7%
Ranked in the US
#26
Maryland has 84.20% of days with good air quality, 0.70% of days with unhealthy air quality, and 15.10% of days with moderate air quality. Maryland has good air quality for the most part, but it experiences moderate and unhealthy air quality on a significant number of days.
Massachusetts
Good Air Quality Days
87.1%
Ranked in the US
#11
Moderate Air Quality Days
12.5%
Ranked in the US
#40
Unhealthy Air Quality Days
0.5%
Ranked in the US
#20
In Massachusetts, 87.10% of days have good air quality, while 0.50% of days have unhealthy air quality, and 12.50% of days have moderate air quality. Massachusetts has relatively good air quality overall, with most of its days being classified as good. However, the state does experience moderate air quality on a significant number of days.
Michigan
Good Air Quality Days
79.9%
Ranked in the US
#37
Moderate Air Quality Days
19.4%
Ranked in the US
#11
Unhealthy Air Quality Days
0.7%
Ranked in the US
#27
Michigan has a good air quality record, with 79.9% of days classified as good air quality days. The state has a low percentage of unhealthy air quality days at 0.7% and a moderate percentage of moderate air quality days at 19.4%. Michigan is home to many industrial facilities and has a large transportation sector, which can contribute to air pollution. However, the state has implemented a variety of measures to improve air quality, including regulations on power plant emissions and restrictions on open burning.
Minnesota
Good Air Quality Days
83.4%
Ranked in the US
#24
Moderate Air Quality Days
15.4%
Ranked in the US
#27
Unhealthy Air Quality Days
1.2%
Ranked in the US
#36
Minnesota has a good air quality rating of 83.4%, with moderate air quality making up 15.4%, and unhealthy air quality making up 1.2% of the days. The state's air quality is relatively good due to its low population density and strict environmental regulations. However, Minnesota still faces challenges with air pollution, particularly in urban areas, where transportation and industry contribute to poor air quality.
Mississippi
Good Air Quality Days
85.5%
Ranked in the US
#18
Moderate Air Quality Days
14.5%
Ranked in the US
#32
Unhealthy Air Quality Days
0%
Ranked in the US
#3
Mississippi has 85.50% of days with good air quality, 0% of days with unhealthy air quality, and 14.50% of days with moderate air quality. Mississippi has good air quality overall, with no days classified as unhealthy. However, the state does experience moderate air quality on a significant number of days.
Missouri
Good Air Quality Days
86.1%
Ranked in the US
#16
Moderate Air Quality Days
13.4%
Ranked in the US
#37
Unhealthy Air Quality Days
0.4%
Ranked in the US
#18
Missouri has 86.10% of days with good air quality, 0.40% of days with unhealthy air quality, and 13.40% of days with moderate air quality. Missouri has good air quality overall, with the majority of its days being classified as good.
Montana
Good Air Quality Days
80.8%
Ranked in the US
#34
Moderate Air Quality Days
15.9%
Ranked in the US
#25
Unhealthy Air Quality Days
3.3%
Ranked in the US
#48
Montana has a good air quality record, with 80.8% of days classified as good air quality days. However, the state also experiences a significant number of unhealthy air quality days, with 3.3% of days falling into this category. Wildfires, industrial activities, and transportation emissions are some of the factors that contribute to poor air quality in Montana. Additionally, the state's geography can trap air pollution in valleys and basins, leading to localized air quality issues.
Nebraska
Good Air Quality Days
86.8%
Ranked in the US
#12
Moderate Air Quality Days
12.6%
Ranked in the US
#39
Unhealthy Air Quality Days
0.5%
Ranked in the US
#21
Nebraska has 86.80% of days with good air quality, 0.50% of days with unhealthy air quality, and 12.60% of days with moderate air quality. Nebraska has good air quality for the most part, but it experiences moderate air quality on a fair number of days.
Nevada
Good Air Quality Days
72.5%
Ranked in the US
#47
Moderate Air Quality Days
22.8%
Ranked in the US
#6
Unhealthy Air Quality Days
4.7%
Ranked in the US
#50
Nevada has the fifth worst air quality in the US with 72.50% good air quality days, 4.70% unhealthy air quality days, and 22.80% moderate air quality days. Nevada's poor air quality is caused by its geography and weather patterns, with frequent inversions that trap pollutants in the air. The state's population growth and increased industrialization also contribute to air pollution.
New Hampshire
Good Air Quality Days
91%
Ranked in the US
#6
Moderate Air Quality Days
8.5%
Ranked in the US
#47
Unhealthy Air Quality Days
0.5%
Ranked in the US
#22
New Hampshire has the sixth best air quality in the US with 91% of good air quality days, 0.50% of unhealthy air quality days, and 8.50% of moderate air quality days. New Hampshire's location in the northeastern US and relatively low population density help to keep its air quality clean.
New Jersey
Good Air Quality Days
82.3%
Ranked in the US
#27
Moderate Air Quality Days
16.9%
Ranked in the US
#22
Unhealthy Air Quality Days
0.8%
Ranked in the US
#30
New Jersey has a good air quality rating of 82.3%, with moderate air quality making up 16.9%, and unhealthy air quality making up 0.8% of the days. The state's air quality has improved significantly in recent years due to efforts to reduce emissions from transportation and industry. However, New Jersey still faces challenges with air pollution, particularly in urban areas, where transportation and industry contribute to poor air quality.
New Mexico
Good Air Quality Days
78.9%
Ranked in the US
#41
Moderate Air Quality Days
19.3%
Ranked in the US
#12
Unhealthy Air Quality Days
1.7%
Ranked in the US
#40
New Mexico has good air quality for 78.9% of days, while 1.7% of days had unhealthy air quality, and 19.3% of days were moderate. Dust and vehicle emissions are the primary sources of air pollution in the state, with the oil and gas industry also contributing to poor air quality in certain regions. The state has also been affected by wildfires, which can significantly impact air quality.
New York
Good Air Quality Days
88.7%
Ranked in the US
#8
Moderate Air Quality Days
10.6%
Ranked in the US
#44
Unhealthy Air Quality Days
0.6%
Ranked in the US
#23
New York has the eighth best air quality in the US with 88.70% of good air quality days, 0.60% of unhealthy air quality days, and 10.60% of moderate air quality days. Despite being a densely populated state, New York's strict air pollution regulations and relatively low levels of industrial activity help to maintain its air quality.
North Carolina
Good Air Quality Days
86.3%
Ranked in the US
#15
Moderate Air Quality Days
13.7%
Ranked in the US
#36
Unhealthy Air Quality Days
0.1%
Ranked in the US
#5
North Carolina has 86.30% of days with good air quality, 0.10% of days with unhealthy air quality, and 13.70% of days with moderate air quality. North Carolina has good air quality for the most part, with only a very small number of days classified as unhealthy.
North Dakota
Good Air Quality Days
81.1%
Ranked in the US
#30
Moderate Air Quality Days
15.8%
Ranked in the US
#26
Unhealthy Air Quality Days
3.2%
Ranked in the US
#46
North Dakota has a good air quality rating of 81.1%, with moderate air quality making up 15.8%, and unhealthy air quality making up 3.2% of the days. The state's air quality is generally good due to its low population density and strict environmental regulations. However, pollution from the oil and gas industry can impact air quality in certain areas, particularly in the western part of the state.
Ohio
Good Air Quality Days
80.9%
Ranked in the US
#32
Moderate Air Quality Days
18.8%
Ranked in the US
#17
Unhealthy Air Quality Days
0.3%
Ranked in the US
#14
Ohio has good air quality most of the time, with 80.9% of days classified as good air quality days. The state has a low percentage of moderate air quality days at 0.3%, and a slightly higher percentage of unhealthy air quality days at 18.8%. Ohio is a densely populated state with many industrial and manufacturing facilities, which can contribute to air pollution. Additionally, emissions from transportation, such as cars and trucks, can also contribute to poor air quality.
Oklahoma
Good Air Quality Days
76.7%
Ranked in the US
#44
Moderate Air Quality Days
22.2%
Ranked in the US
#7
Unhealthy Air Quality Days
1.1%
Ranked in the US
#35
Oklahoma has the eighth worst air quality in the US with 76.70% good air quality days, 1.10% unhealthy air quality days, and 22.20% moderate air quality days. Oklahoma's air pollution is mainly caused by transportation emissions, industrial facilities, and oil and gas production. Weather patterns, such as droughts and wildfires, also worsen air quality.
Oregon
Good Air Quality Days
83%
Ranked in the US
#26
Moderate Air Quality Days
14.1%
Ranked in the US
#34
Unhealthy Air Quality Days
2.9%
Ranked in the US
#45
Oregon has a good air quality rating of 83%, with moderate air quality making up 14.1%, and unhealthy air quality making up 2.9% of the days. The state's air quality is generally good due to its strict environmental regulations and low population density. However, the state still faces challenges with air pollution from transportation and industry in urban areas, as well as wildfires in certain parts of the state.
Pennsylvania
Good Air Quality Days
79.2%
Ranked in the US
#39
Moderate Air Quality Days
20.2%
Ranked in the US
#10
Unhealthy Air Quality Days
0.6%
Ranked in the US
#24
Pennsylvania has a good air quality record, with 79.2% of its days having good air quality. However, 0.6% of days were unhealthy, and 20.2% were moderate. The state has various sources of air pollution, including power plants, industrial facilities, and transportation. Pittsburgh and Philadelphia, in particular, have struggled with poor air quality due to their high traffic volume and industrial activity.
Rhode Island
Good Air Quality Days
86.7%
Ranked in the US
#13
Moderate Air Quality Days
12.4%
Ranked in the US
#41
Unhealthy Air Quality Days
0.8%
Ranked in the US
#31
Rhode Island has 86.70% of days with good air quality, 0.80% of days with unhealthy air quality, and 12.40% of days with moderate air quality. Rhode Island has good air quality for the most part, with the majority of its days being classified as good.
South Carolina
Good Air Quality Days
84.9%
Ranked in the US
#20
Moderate Air Quality Days
15.1%
Ranked in the US
#30
Unhealthy Air Quality Days
0.1%
Ranked in the US
#6
South Carolina has 84.90% of days with good air quality, 0.10% of days with unhealthy air quality, and 15.10% of days with moderate air quality. South Carolina has good air quality for the most part, with only a very small number of days classified as unhealthy.
South Dakota
Good Air Quality Days
82.1%
Ranked in the US
#29
Moderate Air Quality Days
16.6%
Ranked in the US
#24
Unhealthy Air Quality Days
1.3%
Ranked in the US
#38
South Dakota has a good air quality rating of 82.1%, with moderate air quality making up 16.6%, and unhealthy air quality making up 1.3% of the days. The state's air quality is generally good due to its rural character and low population density. However, pollution from agriculture and wildfires can impact air quality in certain areas, particularly during the summer months.
Tennessee
Good Air Quality Days
84.5%
Ranked in the US
#21
Moderate Air Quality Days
15.2%
Ranked in the US
#28
Unhealthy Air Quality Days
0.3%
Ranked in the US
#15
Tennessee has 84.50% of days with good air quality, 0.30% of days with unhealthy air quality, and 15.20% of days with moderate air quality. Tennessee has good air quality overall, with only a small number of days classified as unhealthy.
Texas
Good Air Quality Days
80.5%
Ranked in the US
#35
Moderate Air Quality Days
18.5%
Ranked in the US
#18
Unhealthy Air Quality Days
1%
Ranked in the US
#34
Texas has a good percentage of good air quality days at 80.5%, but it also experiences a relatively high percentage of unhealthy air quality days at 1%. The state has a high number of industrial facilities and transportation emissions, which contribute significantly to air pollution. Additionally, the state experiences occasional dust storms and wildfires that can worsen air quality. The hot and sunny climate in many parts of Texas also leads to the formation of ground-level ozone, which can harm public health.
Utah
Good Air Quality Days
70.2%
Ranked in the US
#48
Moderate Air Quality Days
26.6%
Ranked in the US
#4
Unhealthy Air Quality Days
3.2%
Ranked in the US
#47
Utah has the fourth worst air quality in the US with 70.20% good air quality days, 3.20% unhealthy air quality days, and 26.60% moderate air quality days. Utah's geography and weather patterns contribute to poor air quality, with frequent inversions that trap pollution in the Salt Lake Valley. Additionally, the state's industrial growth and population growth contribute to air pollution.
Vermont
Good Air Quality Days
91.3%
Ranked in the US
#5
Moderate Air Quality Days
8.5%
Ranked in the US
#48
Unhealthy Air Quality Days
0.2%
Ranked in the US
#11
Vermont has the fifth best air quality in the US with 91.30% of good air quality days, 0.20% of unhealthy air quality days, and 8.50% of moderate air quality days. Vermont's low population density and location in the northeastern US help to maintain its clean air quality.
Virginia
Good Air Quality Days
91.5%
Ranked in the US
#4
Moderate Air Quality Days
8.4%
Ranked in the US
#49
Unhealthy Air Quality Days
0.2%
Ranked in the US
#12
Virginia has the fourth best air quality in the US with 91.50% of good air quality days, 0.20% of unhealthy air quality days, and 8.40% of moderate air quality days. Virginia's location along the Atlantic coast and the presence of the Appalachian Mountains help to keep pollutants away from the state.
Washington
Good Air Quality Days
88.7%
Ranked in the US
#9
Moderate Air Quality Days
9.7%
Ranked in the US
#46
Unhealthy Air Quality Days
1.6%
Ranked in the US
#39
Washington has the ninth best air quality in the US with 88.70% of good air quality days, 1.60% of unhealthy air quality days, and 9.70% of moderate air quality days. Washington's location on the Pacific coast and the presence of the Cascade Mountains help to keep pollutants away from the state.
West Virginia
Good Air Quality Days
86.7%
Ranked in the US
#14
Moderate Air Quality Days
13.2%
Ranked in the US
#38
Unhealthy Air Quality Days
0%
Ranked in the US
#4
West Virginia has 86.70% of days with good air quality, 0% of days with unhealthy air quality, and 13.20% of days with moderate air quality. West Virginia has good air quality overall, with no days classified as unhealthy. However, the state does experience moderate air quality on a significant number of days.
Wisconsin
Good Air Quality Days
79.8%
Ranked in the US
#38
Moderate Air Quality Days
19.3%
Ranked in the US
#13
Unhealthy Air Quality Days
0.9%
Ranked in the US
#33
Wisconsin has a good air quality record, with 79.8% of days classified as good air quality days. The state has a low percentage of unhealthy air quality days at 0.9% and a moderate percentage of moderate air quality days at 19.3%. Wisconsin has a mix of urban and rural areas, and air quality varies depending on the location. Industrial activities, transportation emissions, and agricultural activities can contribute to air pollution in the state.
Wyoming
Good Air Quality Days
78.9%
Ranked in the US
#42
Moderate Air Quality Days
19.3%
Ranked in the US
#14
Unhealthy Air Quality Days
1.8%
Ranked in the US
#41
Wyoming has the tenth worst air quality in the US with 78.90% good air quality days. The state experienced 1.80% unhealthy air quality days and 19.30% moderate air quality days. The primary contributor to air pollution in Wyoming is the burning of fossil fuels for energy production and transportation. Wyoming is a major producer of coal, oil, and natural gas, and the energy sector is the largest source of pollution in the state. Additionally, Wyoming experiences high levels of wildfire smoke, particularly during the summer months, which contributes to poor air quality.
FAQs
What state has the best air quality ?
Hawaii has the best air quality in the US with 99.40% of good air quality days.
What state has the worst air quality ?
California has the worst air quality in the US with only 60.60% of good air quality days.
Need to survey a highly targeted audience?
Talk to our Experts