Tick Season in Wisconsin: Types of Ticks, Diseases, and How to Stay Protected

Wisconsin’s warm months are an invitation to get outside — but they also mark the return of one of the state’s most persistent health concerns: ticks. In recent decades, Wisconsin has experienced wetter and warmer climate, creating more hospitable conditions for ticks. Whether you’re hiking a trail in the Northwoods, hunting in the fall, or simply working in your backyard, understanding tick season in Wisconsin can make a real difference in protecting your health.

Tick-borne diseases were once primarily a problem in western and northern Wisconsin, but just in the past 10 to 15 years, ticks have spread across the state so that cases of tick-borne illnesses are now being reported from every county. Knowing when ticks are most active, which species to watch for, and what steps to take if you find one are the foundations of staying safe all season long.

When Is Tick Season in Wisconsin

Tick exposure can occur year-round, but ticks are most active during warmer months, particularly April through September. That said, different tick life stages have their own activity windows, and understanding those patterns helps you know when your risk is highest.

Tick activity in Wisconsin peaks from May through July and again from October through November. Residents should be vigilant year-round, especially during these months when ticks are most active. The spring surge corresponds with adult ticks emerging from winter dormancy, while the summer peak reflects the emergence of nymphs — the most dangerous stage because of their tiny size.

When tick bite-related emergency department visits begin to increase in the spring, it typically corresponds with adult ticks becoming more active in the environment. That spring increase then moves into a summer peak, which corresponds with when nymphal stage ticks typically emerge.

Key Insight: Most cases of Lyme disease occur during June and July. However, it’s possible to get Lyme disease whenever ticks are active, and ticks are active when temperatures are above freezing.

Ticks are also being found farther north than before thanks to changing patterns that keep weather warmer longer. Weather, temperature, and rainfall patterns are changing, and ticks can better survive over the winter. This means the traditional boundaries of tick season in Wisconsin are gradually expanding, and year-round awareness is increasingly important. If you spend time outdoors during goose hunting season in Wisconsin or trout fishing season, tick awareness should be part of your preparation.

Types of Ticks Found in Wisconsin

There are at least 16 reported species of ticks in Wisconsin, but only a few feed on and spread diseases to humans. The most commonly encountered are the deer tick (Ixodes scapularis, called the blacklegged tick by specialists) and the wood tick (Dermacentor variabilis, called the American dog tick by specialists).

Here is a closer look at the three primary tick species you may encounter:

Tick Species	Also Known As	Appearance	Primary Activity	Main Disease Risk
Ixodes scapularis	Deer tick / Blacklegged tick	Reddish to dark brown; no white markings; sesame seed size (adult)	Spring & Fall (adults); May–August (nymphs)	Lyme disease, anaplasmosis, babesiosis, Powassan virus
Dermacentor variabilis	Wood tick / American dog tick	Larger; white markings on body	Spring & Summer	Rocky Mountain Spotted Fever (rare in WI)
Amblyomma americanum	Lone star tick	Rounder body; female has white spot on back	Spring through Summer	STARI rash illness; ehrlichiosis

Blacklegged or deer ticks are no larger than a sesame seed as a juvenile and only slightly bigger as an adult. Males are all black while females are dark brown to reddish-orange with a dark patch on their upper bodies. Blacklegged ticks are the primary ticks that transmit Lyme disease, anaplasmosis, babesiosis, and Powassan virus.

The wood tick is also known as the American dog tick in other parts of the United States. Nymphs typically feed on smaller mammals such as rabbits, while adults feed on larger animals. The wood tick is incredibly common and is known to transmit the bacteria causing Rocky Mountain Spotted Fever.

Pro Tip: Nymphs are of particular concern — before feeding, they are the size of a poppy seed, making them incredibly difficult to find. Studies by the University of Wisconsin-Madison found an average nymphal infection rate of Borrelia burgdorferi, the bacteria that causes Lyme disease, around 20%.

The lone star tick is rounder in shape, and females have a distinctive white spot in the middle of their back, while males have white markings near the rear. The lone star tick is more prevalent in the southern United States but can be found in Wisconsin, and the University of Wisconsin-Madison receives more submissions of these ticks every year, typically from the southern half of the state. To understand more about how ticks reproduce and spread, visit our guide on how ticks reproduce.

Tick-Borne Diseases in Wisconsin

There are many diseases that can be spread by ticks in Wisconsin. Anaplasmosis, babesiosis, ehrlichiosis, Lyme disease, Powassan virus infection, and Rocky Mountain Spotted Fever are among them, and most are spread by the black-legged tick.

Wisconsin is one of the states with the highest number of Lyme disease cases each year. The Wisconsin Department of Health Services reported more than 5,300 incidents of the disease in 2022. Researchers at UW-Madison have found that approximately 40% of adult deer ticks in Wisconsin currently carry the microorganism responsible for Lyme disease.

Lyme Disease: Lyme disease is transmitted through the bite of a blacklegged tick. Symptoms include fever, headache, fatigue, joint pain, swelling, and skin rash known as erythema migrans. It sometimes starts with a bulls-eye or dusky red, round rash followed by flu-like illness. Lyme disease commonly progresses to severe fatigue, joint pain, and swelling if not treated early. A doctor can treat most cases with antibiotics.

Anaplasmosis: Anaplasmosis is also transmitted through the bite of a blacklegged tick. Symptoms include fever, headache, muscle aches, chills, nausea, vomiting, joint pain, fatigue, and in rare cases, skin rash. A doctor can treat most cases with antibiotics.

Babesiosis: Babesiosis is a disease that infects red blood cells and can be life-threatening to those with a weak immune system, causing flu-like symptoms. July to August are peak months for positive babesiosis laboratory test results, raising the risk by seven times compared to other months.

Powassan Virus: Ticks are vectors of microorganisms that cause diseases such as Lyme disease, anaplasmosis, ehrlichiosis, Powassan (deer tick virus), and babesiosis. Powassan virus is rare but serious — unlike Lyme disease, it can be transmitted in as little as 15 minutes of tick attachment. Learn more about tick-borne encephalitis and related neurological tick diseases.

Important Note: Signs and symptoms of Lyme disease include fever, joint pain, headaches, muscle pain, brain fog, and the EM (erythema migrans) rash or bullseye rash. Keep in mind that you can still have Lyme disease and not develop the bullseye rash.

Rocky Mountain Spotted Fever (RMSF): The wood tick is known to transmit the bacteria causing Rocky Mountain Spotted Fever. Fortunately, RMSF is not currently prevalent in Wisconsin, with the Wisconsin Department of Health Services receiving reports of only 5–10 human cases each year.

STARI (Southern Tick-Associated Rash Illness): People bitten by a lone star tick occasionally develop a circular rash. This condition has been named STARI, and the rash can be accompanied by fatigue, headache, fever, and muscle pains.

High-Risk Areas and Habitats in Wisconsin

Ticks are commonly found throughout Wisconsin. They are prevalent in wooded areas, tall grass, and brush, along roadsides and walkways, waiting to cling to people and pets just passing by. The density of tick populations can vary, but they are a notable concern, especially in areas with dense vegetation.

Lyme disease has been reported in every county in the state, with the highest incidence in the northwestern region. People in northwest Wisconsin are at greatest risk for having a positive laboratory test result. However, that doesn’t mean the rest of the state is low-risk. It is important to remember that ticks are present in all counties in Wisconsin, and people living in any county can contract Lyme disease and other tick-borne diseases.

Hikers, hunters, and farmers are at the highest risk as they brush up against vegetation where ticks reside, but anyone who spends time outdoors, including in their yards, may potentially be at risk in Wisconsin. If you enjoy pheasant hunting in Wisconsin or dove hunting, be especially vigilant after time spent in fields and brushy cover.

• Wooded areas and forest edges — Dense tree cover with leaf litter provides ideal tick habitat
• Tall grass and meadows — Ticks wait on grass blades for a passing host
• Brushy trail edges — The border between woods and open areas is a prime tick zone
• Residential yards near woods — Nymphal deer ticks can be in your lawn — researchers found them in mowed grass near woods while sampling at home sites in Eau Claire, Wisconsin and near Mirror Lake.
• Wildlife-heavy areas — Changes in forestry practices and increases in deer and white-footed mouse populations, which host the ticks, have led to increased prevalence of ticks.

Common Mistake: Many people assume ticks only live deep in the woods. In reality, ticks typically live in wooded areas, tall grass, and brush. They do not jump or fly but can attach to the end of a leaf or blade of grass and wait for a person or animal to brush against it.

How to Protect Yourself, Children and Pets During Tick Season in Wisconsin

Reducing your exposure to ticks is the most effective strategy for avoiding tick-borne illness. A combination of protective clothing, repellents, and regular tick checks gives you the strongest defense during Wisconsin’s tick season.

Protective Clothing

Wear long sleeves, long pants, and tall socks. This helps keep ticks on the outside of clothing rather than on your skin. Wear light-colored clothing to make ticks easier to spot. Tuck shirts into pants, and tuck pants into shoes or socks — this keeps ticks on the outside of clothing.

Repellents

Repellents should contain one of these active ingredients: 20–30% DEET, 10–20% Picaridin, 15–20% IR3535, or 30–40% oil of lemon eucalyptus. Do not use oil of lemon eucalyptus on children under 3 years of age.

Use permethrin on clothes, shoes, and gear but do not apply it directly to skin. Permethrin is a pesticide that kills ticks when they crawl on your clothes and can last through several washes.

Tick Checks

To effectively transmit the bacteria that cause Lyme disease, deer ticks have to be attached and feeding for extended periods of time, usually at least 24 hours. This time requirement means that daily checks can help find and remove ticks before they’ve had a chance to transmit the bacteria.

Check areas that are dark, warm, and cozy — your armpits, belt line, groin, hairline, and behind the ears. Do this immediately after you come in from any activity considered high risk.

Throw your clothes in the dryer for 20 minutes on high heat, which will kill any ticks that are potentially on your clothes.

Protecting Children

Parents should apply repellents to children, using caution and avoiding hands, eyes, and mouth. Dress children in long sleeves and pants when playing near wooded areas or tall grass, and check them thoroughly after outdoor play, paying special attention to the hairline, neck, and behind the ears.

Protecting Pets

Ticks are just as dangerous to pets as they are to humans. Since ticks are so small, they can be difficult to find in the dense fur of a dog or cat, but they can commonly be found around their head, ears, neck, or feet. In animals, symptoms may not be present for seven to 21 days, so monitor your pet closely and do full-body checks.

Don’t forget about four-legged friends — pets that spend time outdoors can also be affected by tick-borne diseases. Veterinarians should be consulted to select appropriate preventative tick products. Topical repellent sprays are also available for those times you take your pets hiking in prime tick habitat. For more guidance on protecting your dog, read our tips on preventing tick-borne diseases in dogs. You can also learn about animals that naturally eat ticks as part of understanding tick ecology.

Reducing Ticks in Your Yard

• Clear tall grass, brush, and leaf litter from the yard or trails.
• Use wood chips or gravel as a barrier between lawns and wooded areas, and around patios and play equipment.
• Mow lawns often and remove cut grass and leaves.
• Keep tables, swing sets, and other play equipment away from woods, shrubs, and tall grass — place them in a sunny location if possible.
• Don’t feed deer.

Pro Tip: If you spend a lot of time outdoors, download The Tick App — a free app from partners at the Midwest Center of Excellence for Vector-Borne Disease. It allows people living in areas with a high risk of Lyme disease to report ticks and learn tick bite prevention tips.

What to Do If You Find a Tick in Wisconsin

Finding a tick on your skin is understandably alarming, but staying calm and acting quickly is the most important thing you can do. Several popular homeopathic remedies can cause more harm than good. The proper removal procedure does not involve petroleum jelly, matches, nail polish remover, or simply pinching the tick off.

Follow these steps for safe tick removal:

1. Gather your tools. You’ll want a clean pair of fine-tipped tweezers, rubbing alcohol, or soap and water.
2. Grasp the tick correctly. Grasp the tick as close to the surface of the skin as possible.
3. Pull steadily upward. Apply steady, even pressure and pull up, making sure not to twist the tick as you pull it out. Alternatively, place the tweezers at the head of the tick perpendicular to its body and pull straight up until it releases from the skin. Tick removal tools like the tick twister and tick key can help remove a tick without squeezing the body.
4. Clean the area. Once the tick has been removed, clean the bite area and your hands with soap and water or rubbing alcohol if available.
5. Monitor for symptoms. If you were bitten by a tick, or think you may have been bitten, monitor yourself for rash, fever, new muscle and joint pain, and new fatigue for 30 days.

Important Note: You may notice a small bump or redness at the site of the bite. This should go away in one to two days. If it does not, consult a doctor. If you are bitten by a tick and see a bullseye rash, you should consult a doctor right away.

If you have been bitten by a tick, getting it tested for any diseases isn’t recommended. The only way to know if a tick bite made you sick is through an evaluation performed by a health care provider.

In Wisconsin, where Lyme disease is common, it’s especially important to seek medical help soon after your tick exposure — a single dose of antibiotics could help prevent illness.

Reporting Tick Bites and Tick-Borne Illness in Wisconsin

Wisconsin has several resources in place to help residents report tick encounters and get support after a tick bite. Using these tools benefits both your personal health and statewide tick research efforts.

Wisconsin DHS Tick Identification Service

The Wisconsin Department of Health Services offers a fast and simple Tick Identification Service based on a few questions and photographs you submit online. You can send a submission if you live in Iowa, Illinois, Michigan, Minnesota, and Wisconsin. The Tick Identification Service cannot determine if the tick you found was carrying any germs or whether it made you sick. If you were bitten by a tick, monitor yourself for rash, fever, new muscle and joint pain, and new fatigue for 30 days.

The Tick App

The Tick App is a free app from partners at the Midwest Center of Excellence for Vector-Borne Disease. It allows people living in areas with a high risk of Lyme disease to report ticks and learn tick bite prevention tips, and it also helps researchers understand ticks and the illnesses they spread. This app is available for both iOS and Android devices and is helping researchers get a better understanding of tick habitat in the US.

Marshfield Clinic Research Institute — Citizen Tick Collecting

Building on growing community support, Marshfield Clinic Research Institute asks Wisconsin residents to send in ticks they find while working and recreating outside. In 2024, the Research Institute launched the Tick Inventory via Citizen Science (TICS) to identify ticks found in the state — information that can be used to assess risk of encountering a tick-borne disease.

In both 2024 and 2025, nearly 6,000 ticks were collected annually from nearly every Wisconsin county. To participate or request a collection kit, contact Marshfield Clinic Research Institute at marshfieldresearch.org.

Reporting to Your Healthcare Provider

Symptoms of tick-borne diseases may include fever, chills, muscle aches, fatigue, headache, and rash (not present in all tick-borne diseases). Contact your doctor right away if you have any of these symptoms.

The bi-weekly Tick Surveillance Report from Wisconsin DHS summarizes tick activity based on tick collections from three sentinel sites in Iowa County, Lincoln County, and Waupaca County. The most recent report and all tick reports for the 2025–2026 tick season are available. You can monitor this data at the Wisconsin DHS tick surveillance page.

Key Insight: Tick-borne illness is a reportable condition in Wisconsin. Your healthcare provider is required to report confirmed cases to the Wisconsin DHS, which helps track disease trends statewide. If you’re diagnosed with Lyme disease, anaplasmosis, or another tick-borne illness, that data contributes directly to public health monitoring and future prevention efforts.

Staying informed and taking consistent precautions is the best approach to enjoying Wisconsin’s outdoors safely. Whether you’re spending time in the woods during pheasant season, fishing along wooded riverbanks during trout season, or simply enjoying your backyard, a little tick awareness goes a long way toward keeping you and your family healthy all year round.