Wisconsin Deer Tick Activity Rose in October
As tick bite emergencies spike, Wisconsin residents should remain vigilant for signs of Lyme disease.
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 has entered a secondary peak of deer tick activity this October, marking a seasonal surge in tick-related emergency room visits. This follows a record year in 2025 where the state reported 8,929 cases of Lyme disease.
Why it matters
Understanding this autumn surge is critical for residents because recent research indicates that adult ticks encountered in the fall may carry higher rates of Lyme-causing bacteria than those found in the spring. Heightened awareness can help you spot tick bites earlier and discuss potential symptoms with your doctor.
A 2024 study of 707 adult female deer ticks found that 51 percent carried the bacteria that causes Lyme disease. This research underscores a higher bacterial prevalence in fall ticks compared to those active during the spring.
The players
Centers for Disease Control and Prevention
The national public health agency responsible for monitoring tick-borne diseases and issuing safety alerts.
Tick Inventory Citizen Science Project
A research initiative that tracks tick populations through specimens collected and mailed in by community members.
The details
Adult deer ticks wait in tall grass and bushy areas, attaching themselves to hosts as they pass by. The autumn activity surge reflects the natural lifecycle of the adult deer tick, which reaches a second population peak during October. Residents contribute to tracking these trends through the Tick Inventory Citizen Science Project by mailing in ticks for evaluation.
Timeline
2024: A study found higher bacterial prevalence in fall ticks.
2025: Wisconsin reported 8,929 total cases of Lyme disease.
June and July: These months see the highest number of annual Lyme cases.
October: This month experiences an annual second peak of tick activity and ER visits.
April 2026: The CDC issued an alert regarding nationwide tick bite surges.
Health Landscape
The current autumn tick activity sits within the historical context of rising Lyme disease reporting in the state. This trend is exacerbated by both natural lifecycle peaks and the implementation of more precise, automated public health reporting systems.
Residents should perform thorough tick checks after spending time in grassy or bushy areas, especially during the current October peak. If you notice a tick bite or develop flu-like symptoms, contact your primary care provider to discuss potential testing or evaluation.
The takeaway
While most Lyme cases are reported in mid-summer, autumn remains a high-risk period for tick bites in Wisconsin. Vigilance should continue through the fall, and any unexplained symptoms following time spent outdoors should be discussed with a physician.
Further reading
For more on managing exposure to local pests and related health risks, visit 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?
