Wisconsin Deer Tick Activity Has Peaked
State residents see an increase in tick bites and Lyme disease cases during the autumn months.
Updated on Sept. 24, 2026 in Allergies
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Do you take extra precautions against ticks when spending time outdoors during the fall?
Wisconsin is experiencing a second surge in deer tick activity this October, mirroring a trend that aligns with the natural lifecycle of the parasite. This seasonal increase has prompted warnings for residents as ER visits related to tick bites rise.
Why it matters
Understanding this autumn peak is crucial for public health, as researchers have identified that fall ticks carry a higher prevalence of Lyme-causing bacteria compared to spring populations. Staying vigilant in bushy areas during this window remains the primary defense against infection.
A 2024 study of 707 adult female deer ticks confirmed 51 percent carried Lyme-causing bacteria. This data follows a 2025 record high of 8,929 reported Lyme disease cases across the state.
The players
Centers for Disease Control and Prevention
The national public health agency issued an alert in April 2026 regarding the surge in tick bite incidents.
Tick Inventory Citizen Science Project
This research initiative monitors tick populations by collecting and testing specimens mailed in by residents.
The details
Adult deer ticks are currently active in tall grass and bushy areas, waiting for hosts to pass by as part of their natural life cycle. The Tick Inventory Citizen Science Project continues to track the surge by analyzing ticks submitted by local residents.
Timeline
June and July mark the period when most annual Lyme disease cases occur.
2024 saw a study identify higher bacterial prevalence in fall ticks compared to spring ticks.
2025 recorded a total of 8,929 Lyme disease cases in Wisconsin.
April 2026 was when the CDC issued a national alert regarding spikes in tick bites.
October serves as the annual second peak for both tick activity and emergency room visits.
Health Landscape
The current autumn surge in Wisconsin aligns with patterns identified by the Centers for Disease Control and Prevention's April 2026 tick bite alert. This trend underscores a broader shift toward year-round monitoring of tick-borne illnesses as seasonal behavior patterns change.
Residents should remain vigilant when entering tall grass or bushy areas throughout October to avoid tick bites. Those who experience symptoms after spending time outdoors should consult a healthcare provider for early testing and treatment options.
The takeaway
The second seasonal peak of deer ticks in October serves as a reminder that the risk of Lyme disease persists well after the summer months. Residents should maintain preventative measures like wearing protective clothing and performing regular tick checks until temperatures drop.
Further reading
For more on managing environmental health risks, visit Wisconsin Allergies.
Source note: This article includes information reported by Wausau Pilot & Review.
Live Poll
Do you take extra precautions against ticks when spending time outdoors during the fall?
