Today’s Tick Risk in Illinois – Real-Time Forecast & Activity Map
Check your ZIP code for local tick activity, real-time risk levels, and prevention insights.
Built from CDC and NOAA data
Surveillance Insights
- Annual Lyme Cases
- Rising Lyme in north; high tick-borne disease diversity in south
- Based on CDC surveillance data
- Long-Term Trend
- Convergence of northern and southern tick species in central state
- Based on CDC surveillance data
- High Risk Zones
- Winnebago, Ogle, Lake, Jackson, Shawnee National Forest, Starved Rock State Park, Cook Forest Preserves
Current Situation in Illinois
Illinois presents a distinct and bifurcated tick risk profile. The tick forecast for Illinois highlights two main danger zones: the high-Lyme risk area in Northern Illinois (bordering Wisconsin) and the Spotted Fever/Ehrlichiosis risk in Southern Illinois. The blacklegged tick is well-established in the northern tier counties and is steadily moving south. The American Dog tick is found statewide. The Lone Star tick is abundant in the southern forests and is creeping northward. Residents in the Chicago suburbs (Collar Counties) are often surprised to learn that their local forest preserves are high-risk areas for Lyme disease, with infection rates in ticks rivaling those in Wisconsin.
Snapshot of the current tick situation in Illinois, based on regional surveillance data and seasonal activity patterns.
- Risk Level
- Moderate to High
- Peak Activity
- May - July
- Dominant Vector
- American Dog Tick (Dermacentor variabilis)
Where Ticks Hide in Illinois
Northern Illinois features a landscape of fragmented forests and "forest preserves" surrounded by dense suburbia—a perfect recipe for high deer numbers and tick proliferation. The Rock River valley is a known corridor for tick expansion. Southern Illinois, home to the Shawnee National Forest, offers deep, contiguous forests, cypress swamps, and rocky bluffs that support a high diversity of tick species. Central Illinois, while largely agricultural, maintains tick populations in river bottoms, woodlots, and state parks. The "edge effect" in suburban Chicago is a major driver of human exposure.
Seasonal Activity Pattern
Tick activity peaks May through July for nymphs in the north, which is the primary window for Lyme transmission. Adult deer ticks are active in fall (October-November) and spring (March-May). In Southern Illinois, tick activity begins earlier in the spring and lasts later into the fall due to the milder climate. Winter activity is possible for adult deer ticks on mild days, especially in the south. Residents should treat "tick checks" as a year-round habit if they spend time in the woods.
Check Your Local Tick Risk
Ready to see current tick activity in your area? Get today's tick forecast and personalized risk assessment for your ZIP code.
Local Vector Analysis
Understanding which ticks are active in Illinois helps you identify threats and take appropriate precautions.
Deer Tick / Blacklegged Tick
Ixodes scapularis
Appearance: Dark reddish-brown body with black shield on back. Adults are 3-5mm.
Peak Season: Adults: Oct-May | Nymphs: May-Aug
Habitat: Deciduous forests, shady moist areas, and leaf litter. Loves the boundary between lawns and woods.
Diseases: Lyme Disease, Anaplasmosis, Babesiosis, Powassan Virus, B. miyamotoi
Lone Star Tick
Amblyomma americanum
Appearance: Distinct white dot or "lone star" on female's back. Reddish-brown body.
Peak Season: Active from early Spring through late Fall
Habitat: Woodlands with dense undergrowth and around animal resting areas.
Diseases: Ehrlichiosis, Alpha-gal Syndrome, STARI, Heartland Virus, Bourbon Virus
Note: Aggressive hunter. Actively pursues hosts.
American Dog Tick
Dermacentor variabilis
Appearance: Brown with white/grey mottling. Ornate white patterns on shield.
Peak Season: Spring and Summer
Habitat: Grassy fields, walkways, and trails. More tolerant of dry conditions than Deer Ticks.
Diseases: Rocky Mountain Spotted Fever, Tularemia
Lyme Disease
Vector: Deer tick (Ixodes scapularis)
Lyme Disease
Lyme disease is a bacterial infection transmitted by deer ticks. If caught early, it's highly treatable with antibiotics. Left untreated, it can cause serious complications affecting joints, heart, and nervous system.
Early Warning Signs
- Erythema migrans (EM) rash - appears in 70-80% of cases
- Bullseye rash (circular red rash with clear center)
- Rash appears 3-30 days after bite
- Fever and chills
Progression & Symptoms
- Severe headaches and neck stiffness
- Facial palsy (loss of muscle tone on one or both sides of face)
- Arthritis with severe joint pain, especially knees
Prevention Strategies
The best way to avoid tick-borne diseases is to prevent tick bites in the first place. These strategies work together to create multiple layers of protection.
Permethrin-Treated Clothing
Permethrin is an insecticide that kills ticks on contact. When applied to clothing, it remains effective through multiple washes.
Daily Tick Checks
Since disease transmission typically requires 24-48 hours of attachment, finding and removing ticks quickly dramatically reduces infection risk.
Landscaping Defense
Creating a tick-hostile environment in your yard reduces the chance ticks will be waiting when you step outside.
Shower Within 2 Hours
Showering after outdoor activity gives you a chance to wash off ticks before they bite.
Tick Bite Protocol
Acting quickly and correctly is your best defense against infection.Follow these 6 critical steps.
Don't Panic
Most tick bites do not transmit disease, especially if removed quickly.
- Infection rates vary by region (20-50%)
- Transmission usually takes 24-48 hours
- Stay calm and use proper technique
Gather Tools
Use fine-tipped tweezers. Avoid fingers or chemicals.
- Fine-tipped tweezers are best
- Rubbing alcohol for cleaning
- Small container to save the tick
Grasp & Pull
Grasp close to skin and pull upward with steady pressure.
- Grab mouthparts near skin (not body)
- Pull straight up—don't twist
- Maintain steady, even pressure
Clean Area
Disinfect the bite site and your hands thoroughly.
- Wash with soap and water
- Apply rubbing alcohol
- Wash hands well
Save Tick
Keep the tick in a sealed container for potential testing.
- Seal in bag or container
- Label with date and location
- Bring to doctor if symptoms appear
Monitor (30 Days)
Watch for rash or flu-like symptoms for a month.
- Check for expanding rash daily
- Watch for fever or fatigue
- Seek care if you feel unwell
When does tick season end in Illinois?
Tick activity winds down after the first hard freeze, which in Illinois typically arrives around Oct 16. See the local first-frost window and city-by-city freeze dates.
Illinois first frost datesAlso worried about mosquitoes in Illinois?
West Nile virus, EEE, and the local mosquito season vary by state. Check your Illinois mosquito risk profile.
View Illinois mosquito forecastStay Safe in Illinois
Get personalized tick forecasts and prevention tips for your area