Utah Experienced Mild Sunday Before Fall Storms

The state saw sunshine and mild temperatures before a transition to showers on the first day of autumn.

Updated on Sept. 20, 2026 in Forecasts

Sunlight hitting the red rock ridges of a desert canyon while dark storm clouds gather in the distant sky over Utah. — Utah experienced mild temperatures on Sunday, with highs reaching the 70s and 90s across the state before a shift to autumn rain and thunderstorms starting Monday. AI Illustration. Upload story photo >

Utah enjoyed pleasant weather on Sunday as high temperatures reached the mid-70s along the Wasatch Front and the low 90s in St. George. This mild conditions precede a shift to rain, with showers and thunderstorms expected to arrive on Monday.

Why it matters

The transition marks a distinct seasonal shift as Utah moves from summer warmth into the first week of fall. Residents should prepare for unsettled conditions that are forecast to persist through the middle of the week.

Sunday high temperatures reached the mid-70s across the Wasatch Front and the low 90s in St. George. Overnight low temperatures have trended 5 degrees cooler than normal.

The details

Clouds are beginning to move into southern Utah, signaling a change in the weather pattern heading into the start of the week. Showers and thunderstorms are expected to develop across the region on Monday and linger through Wednesday.

September 21, 2026: The state experienced a final day of sunshine and mild temperatures.
September 22, 2026: The first day of fall marks the arrival of showers and thunderstorms.
September 23, 2026: Rain and chances for thunderstorms are forecast to persist.

Seasonal Patterns

This transition to cooler, wet weather reflects the broader shift in regional atmospheric patterns following the arrival of the autumnal equinox. These patterns represent a departure from summer heat toward the cooler, unsettled conditions typical of the early autumn season.

Residents should prepare for wet conditions and potential travel delays starting Monday as showers move into the state. Outdoor plans for early in the week may need to be adjusted to accommodate the arrival of rain and possible thunderstorms.

The takeaway

As fall begins, Utah residents should expect a sustained period of cooler and wetter weather through at least Wednesday. It is a good time to check that home gutters are clear and that vehicles are prepared for potentially slick driving conditions.