Today’s Tick Risk in California – 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
Is there a tick outbreak in California in 2026?
California is seeing elevated tick activity in 2026, driven by wet winters that boosted grass and rodent habitat. The western blacklegged tick, the state Lyme disease vector, is most dense in coastal ranges and Sierra foothills. Peak nymph season runs March through June; the live map above shows current conditions.
Surveillance Insights
- Annual Lyme Cases
- Lyme endemic in coastal counties
- Based on CDC surveillance data
- Long-Term Trend
- Urban expansion into oak woodlands increasing risk
- Based on CDC surveillance data
- High Risk Zones
- Mendocino, Sonoma, Marin, Santa Cruz, San Mateo, Santa Clara
Current Situation in California
California's tick landscape is vast and complex. The tick forecast for California emphasizes the risk of Lyme disease in the coastal counties, from Mendocino down to Monterey. The Western Blacklegged Tick is the primary vector. Unlike the East Coast, nymphs here often feed on lizards (which don't transmit Lyme), but the risk to humans remains significant in oak woodlands and chaparral. In Southern California, risks are lower but present in the Santa Monica and San Gabriel mountains.
Snapshot of the current tick situation in California, based on regional surveillance data and seasonal activity patterns.
- Risk Level
- Moderate to High
- Peak Activity
- May - July
- Dominant Vector
- Western Blacklegged Tick (Ixodes pacificus)
Where Ticks Hide in California
Oak woodlands with leaf litter are the highest risk environments. Ticks also thrive in coastal scrub and chaparral, often questing on the underside of leaves or on grass stems. "Hill-topping" behavior has been observed in some species. Redwood forests are generally lower risk due to the tannins, but the edges are dangerous. Parks in the Bay Area (Tilden, Mt. Diablo) are known hotspots.
Seasonal Activity Pattern
California has a unique year-round tick season. Adult Western Blacklegged Ticks are most active in the cool, wet months (November-April). Nymphs, which are harder to spot and more likely to transmit disease, are active in late spring and early summer. "June Gloom" provides perfect humidity for questing ticks.
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 California helps you identify threats and take appropriate precautions.
Western Blacklegged Tick
Ixodes pacificus
Appearance: Similar to deer tick. Dark brown to black. Adults are 3-5mm.
Peak Season: Adults: Oct-May | Nymphs: May-Jul
Habitat: Chaparral, oak woodlands, coastal scrub. Often feeds on lizards as nymphs.
Diseases: Lyme Disease, Anaplasmosis, B. miyamotoi
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
Brown Dog Tick
Rhipicephalus sanguineus
Appearance: Uniform reddish-brown color with no ornate patterns or markings.
Peak Season: Year-round (can survive indoors)
Habitat: On dogs and in kennels. Can survive and reproduce indoors.
Diseases: Rocky Mountain Spotted Fever (in Southwest)
Note: Primarily feeds on dogs. Can establish indoor infestations.
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
Heading to a lake in California?
Live water temperatures and swim conditions for Lake Tahoe, Big Bear Lake, Shasta Lake.
See California lake temperaturesWhen does tick season end in California?
Tick activity winds down after the first hard freeze, which in California typically arrives around Dec 1. See the local first-frost window and city-by-city freeze dates.
California first frost datesAlso worried about mosquitoes in California?
West Nile virus, EEE, and the local mosquito season vary by state. Check your California mosquito risk profile.
View California mosquito forecastStay Safe in California
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