Tick Season in California: What You Need to Know to Stay Safe
May 23, 2026
California’s mild climate and diverse landscapes make it one of the most tick-active states in the country — and unlike many other regions, tick season here doesn’t simply end when summer does. Ticks can be a real concern for hikers, gardeners, pet owners, and families throughout the year.
Whether you spend time in the coastal redwoods, the Sierra Nevada foothills, or your own backyard, understanding when and where ticks are most active gives you the tools to protect yourself and the people you care about. This guide covers everything you need to know about tick season in California, from peak activity windows to the diseases ticks carry and what to do if you find one attached to your skin.
When Is Tick Season in California
In California, ticks can be found at any time of the year, though they are more abundant in spring and winter. That said, activity patterns vary by species and region, so it helps to understand the broader picture.
Ticks in California are known to increase their activity when late fall approaches until the months of May and June. Be particularly watchful during April and May because that’s the peak season for nymphal Western blacklegged ticks. These nymphs are especially concerning because they’re tiny and hard to spot.
Ticks in Northern California typically come out after the first big rain in the fall — often around Halloween — and remain a problem for hikers and others enjoying the outdoors through late spring into early summer.
In Southern California, the risk from ticks remains extremely low, with the season much shorter due to the drier and warmer climate. “There are ticks in Southern California, but it seems they have a narrow window in time when they’re an issue.”
Key Insight: Adult Western blacklegged ticks are most active October through April, while nymphs peak in spring. Both life stages can bite humans, making year-round awareness important.
Adult ticks are most active during the fall and winter months, while nymphal ticks are most active in the spring. Knowing which life stage is active during your outdoor activities can help you take the right precautions at the right time. You can also learn more about how ticks reproduce to better understand why populations fluctuate seasonally.
Types of Ticks Found in California
According to the California Department of Health, around 47 types of tick species have been identified in California, but only eight types of ticks have been known to bite humans. Of those, a handful are the most commonly encountered.
The western blacklegged tick is prevalent in California and is usually found in wooded and brush-covered landscapes. This species is a primary vector for Lyme disease in the western United States, and they prefer large mammals, such as deer, for their adult life stage but will also feed on humans and other mammals in all life stages.
The Rocky Mountain wood tick can be found in shrubby, grassy, and wooded habitats typical of California’s more mountainous regions. This tick species is a known vector for Colorado tick fever, Rocky Mountain spotted fever, and tularemia, and they are most active during the spring and early summer months.
The Pacific Coast tick is widespread in California and can be found in a variety of habitats, from coastal areas to sagebrush and even deserts. While less commonly associated with human diseases, it can transmit spotted fever group germs as well as the bacteria causing tularemia.
| Tick Species | Peak Activity | Primary Diseases | Common Habitat |
|---|---|---|---|
| Western Blacklegged Tick | October – April (adults); Spring (nymphs) | Lyme disease, anaplasmosis, babesiosis | Wooded, brushy areas; coastal ranges |
| Pacific Coast Tick | Spring – early summer | Pacific Coast tick fever, tularemia | Coastal areas, sagebrush, deserts |
| Rocky Mountain Wood Tick | Spring – early summer | Rocky Mountain spotted fever, Colorado tick fever | Mountainous, shrubby, grassy regions |
| American Dog Tick | Spring – summer | Rocky Mountain spotted fever, tularemia | Grassy areas, lower elevations |
| Brown Dog Tick | Year-round (indoors) | Rocky Mountain spotted fever (in dogs) | Homes, kennels, warm environments |
Somewhat unique among ticks, the brown dog tick can complete its entire life cycle indoors, making it a concern especially for pet owners. While brown dog ticks primarily target dogs, they also bite humans, and this species is a growing health threat to people in southern California.
Pro Tip: Ticks cannot fly or jump. They “quest” — hanging out on the ends of grasses or branches to try to grab on to a passerby. Staying in the center of trails dramatically reduces your contact with questing ticks.
Tick-Borne Diseases in California
Ticks become infected with germs — like bacteria, viruses, and parasites — when they feed on the blood of infected animals. Ticks can spread these germs to people and other animals when they bite and feed on their blood. Different types of germs spread by ticks can cause different diseases.
Lyme disease is the most widely known tick-borne illness in California. In California, the bacterium that causes Lyme disease is transmitted by the bite of an infected western black-legged tick. Wild rodents and other small animals are the natural reservoir hosts of the disease. The risk for Lyme disease across most of California is low, but with the exception of Sierra, Santa Cruz, Mendocino, Mariposa and Humboldt counties, the state reported fewer than two confirmed cases per 100,000 people from 2012 through 2021.
Other ticks commonly found in California also spread diseases, including Rocky Mountain spotted fever, Pacific Coast tick fever, anaplasmosis, babesiosis and tularemia, according to the state Department of Public Health.
Babesiosis is a parasitic disease spread through the bite of infected black-legged ticks that infects red blood cells, causing flu-like symptoms and potentially severe or fatal illness, especially in those with weakened immune systems.
Rocky Mountain spotted fever (RMSF) is another serious concern. RMSF is primarily caused by a bite from an American dog tick or wood tick and is considered the most severe illness in the U.S. resulting from a tick bite. Twenty percent of untreated cases lead to fatality, while 3 to 5 percent can also lead to death even under treatment.
Tick-borne relapsing fever is also present in California, particularly in mountain areas. Relapsing fever ticks are typically found in mountain cabins and other dwellings. Exposure often occurs when people stay in rustic or older structures in areas like Big Bear Lake and Lake Tahoe. You can read more about tick-borne encephalitis for a broader look at neurological tick-borne illnesses.
Important Note: If you were bitten by a tick, watch for symptoms of disease that may appear up to 30 days after being bitten. Symptoms can include rashes, which can look very different depending on the person or type of disease. Fever, headache, fatigue, and joint pain are also common warning signs.
Alpha-gal syndrome (AGS) is a tick-borne red meat allergy that is spread by the aggressive lone star tick. AGS is unlike other food allergies in that symptoms — which range from itching and nausea to trouble breathing to life-threatening anaphylaxis — are often delayed by several hours after consumption. Its range includes parts of California.
High-Risk Areas and Habitats in California
California’s diverse ecosystems, ranging from coastal areas to dense forests and grasslands, provide habitats for several tick species. Knowing which environments carry the highest risk helps you plan ahead before heading outdoors.
Northwest California remains a hot spot for ticks carrying disease. Researchers describe much of northwest California as a “hyper endemic” area for Lyme disease. Sierra, Santa Cruz, Mendocino, Mariposa and Humboldt counties have the highest rates of Lyme in the state.
Nymphs of the western blacklegged tick may be encountered in a variety of habitats, but they are most accessible and plentiful in certain types of dense woodlands or forests such as those harboring oak, Pacific madrone, or Douglas fir trees. The nymphs abound in hardwood forests or woodlands carpeted with leaf litter or fir needles, but they are much less abundant in more open habitats such as grassland.
Any activity that places you in direct contact with shed leaves, fir needles, or wood — such as gardening, gathering firewood, picnicking, sitting on logs or against tree trunks, and woodcutting — may increase your risk of encountering nymphs and possibly contracting Lyme disease.
Ticks are commonly found in areas with trees, shrubs, tall grass, rocks, logs and fallen leaves, and along trails. They also live in oak, pine and redwood forests. In campgrounds and parks, ticks have also been found on picnic benches and wood logs, so be alert when sitting or resting while camping or hiking.
Common Mistake: Many people assume their risk is limited to deep wilderness. If you live near natural areas, you may also find ticks in your neighborhood and even your backyard. Suburban yards that back up to open space or wooded areas can be just as risky.
If you enjoy hunting or other outdoor pursuits, be aware that dove hunting season in California falls during active tick periods in many parts of the state. Certain natural predators can also help keep tick populations in check — learn more about animals that eat ticks and their role in local ecosystems.
How to Protect Yourself, Children and Pets During Tick Season in California
Prevention is the most effective tool you have against tick-borne illness. A few consistent habits before, during, and after time outdoors can significantly reduce your risk.
Clothing and Repellent
When possible, wear a long-sleeved shirt and long pants to cover your skin and provide a barrier against ticks. Wear light-colored clothes to help you spot any ticks that might be crawling on you.
Treat clothing and gear, such as boots, pants, socks and tents, with products containing 0.5 percent permethrin. For skin, use EPA-registered repellents containing DEET. You can also use insect repellents particularly around your waist, wrists, and ankles where clothing shifts and exposes skin.
On the Trail and Outdoors
- Stay on trails and avoid brush and grassy areas.
- Tuck your pants into your socks or boots to seal off entry points.
- Check yourself for ticks daily, especially under the arms, in and around the ears, inside the belly button, behind the knees, between the legs, around the waist, and on the hairline and scalp.
- Shower soon after being outdoors.
- Run your clothes through a hot wash and high-heat dryer cycle to kill any remaining ticks, which are susceptible to heat.
Protecting Children
Parents should examine their children especially on the scalp and hairline after any time spent in tick-prone environments. Dress children in the same protective clothing you’d wear yourself, and consider having them wear a hat in heavily wooded areas. Keep them on designated trails and away from leaf litter and fallen logs.
Protecting Pets
Talk to your veterinarian about topical treatments that prevent ticks, as well as the Lyme disease vaccine that is available only for dogs. Make sure to groom your pet after taking them for a walk, as ticks may hang onto their fur for several hours before biting.
Check yourself, your children, and your pets for ticks thoroughly and frequently. Keep children and pets nearby, and for maximum safety, consider keeping your dog on a leash. For more detailed pet protection guidance, see these tips for preventing tick-borne diseases in your dog.
Around Your Home
Keep your yard well-maintained by mowing the lawn, removing brush, and clearing leaf litter. Creating a buffer zone of wood chips or gravel between your lawn and any wooded areas can also reduce tick migration into your yard.
Pro Tip: It is generally thought that if you remove a tick within 24 hours, it has not had time to infect you with Lyme or other diseases. Prompt tick checks after every outdoor outing are one of the most effective preventive measures you can take.
What to Do If You Find a Tick in California
Finding a tick attached to your skin can feel alarming, but staying calm and acting quickly is the right approach. Proper removal reduces the chance of disease transmission significantly.
How to Remove a Tick Safely
- Use tweezers to grab the tick as close to your skin as possible.
- Slowly and steadily pull the tick up and straight out, away from your skin — do not twist or jerk the tick out. Using a slow, steady motion will help prevent damage to the skin at the bite site and will also prevent the tick’s head or mouthparts from breaking off and staying in the skin.
- If you think the head or mouthparts are still in the skin, remove them with tweezers. If you can’t easily remove the mouthparts, leave the area alone and let the skin heal.
- Wash your hands and the bite area with soap and water, then apply an antiseptic or antibiotic ointment to the bite area.
- Dispose of the tick — throw it away in the trash, flush it down the toilet, or save it for identification by a public health agency.
Important Note: Tick removal techniques that don’t work — such as applying nail polish, burning the tick with a match, or swabbing it with soap or petroleum jelly — should not be used because they delay removal and can also be dangerous.
After Removal: What to Watch For
Most people who’ve been infected with the bacteria that leads to Lyme disease will see a red rash at or near the site of the tick bite. The rash enlarges over several days, developing a red ring with a clear or bluish center, resembling a bull’s-eye. At this early stage, people treated with antibiotics usually recover quickly and completely.
If you think the tick has been on your body for 24 hours or more, consider saving it in a sealed bag or container and taking it to your primary care doctor to evaluate whether it’s the kind that carries disease.
Monitor for symptoms such as rash, fever, fatigue, headache, muscle pain, and joint swelling for 30 days. If any of these symptoms occur, call your healthcare provider. Treatment for tick-borne diseases should be based on symptoms, history of exposure, and sometimes blood test results, with most conditions being treatable with a short course of antibiotics.
Reporting Tick Bites and Tick-Borne Illness in California
Reporting tick encounters and illnesses helps California public health authorities track disease trends, identify high-risk areas, and protect communities. Here’s how you can participate in that process.
Reporting a Tick-Borne Illness
If you’ve been diagnosed with a tick-borne illness, your healthcare provider is typically required to report it to the local county health department. If any symptoms occur after a tick bite, call your healthcare provider as soon as possible so that a diagnosis can be made and the case reported through the proper channels.
The California Department of Public Health (CDPH) Vector-Borne Disease Section oversees statewide surveillance of tick-borne diseases. You can contact them at (916) 552-9730 for educational resources or to learn more about reporting procedures in your area.
Submitting a Tick for Identification
Many county vector control districts in California accept ticks for identification. To submit a tick for identification, place it in a sealed zipper bag with a piece of slightly moist (not wet) cotton or paper towel, and be sure to include your email address and/or phone number.
Testing ticks removed from a person for the purposes of medical decision-making is not recommended by the California Department of Public Health — but identification can still help public health agencies track which species are active in your area.
Key Insight: The California Department of Public Health does not recommend that ticks be tested for Lyme disease bacteria to determine if medical treatment is necessary, because testing methods vary in accuracy and tick testing results do not necessarily predict if the person bitten will get Lyme disease. Treatment decisions should always be based on your symptoms and a doctor’s evaluation.
Online Reporting Tools and Resources
Several county health departments and vector control districts also maintain online portals and surveillance maps. The CDC’s interactive tick surveillance maps are a useful tool for checking which tick species have been documented in your county. Local resources such as the East Bay Regional Park District and the UC IPM Program also offer region-specific guidance and up-to-date tick activity advisories.
If you enjoy outdoor recreation and hunting across state lines, it’s worth knowing that tick awareness matters wherever you go. Whether you’re exploring goose hunting season in Wisconsin, pheasant hunting season in Kansas, or hunting closer to home, tick precautions should always be part of your outdoor routine.
Staying informed, checking your body after every outdoor outing, and knowing when and where to seek care are the most effective steps you can take during tick season in California. The good news is that with the right knowledge and habits, you can enjoy everything the Golden State’s outdoors has to offer — safely and confidently.