Tick season in New Jersey runs from April through September, with the highest risk concentrated in late spring and early summer. That said, ticks can be active any time ground temperatures rise above 45°F, which means mild winter days in New Jersey aren’t necessarily tick-free.
Peak Months for Tick Activity
April marks the beginning of consistent tick activity across New Jersey, and it stays elevated through September. Within that window, June and July tend to be the most dangerous months. That’s when nymphal blacklegged ticks (the tiny juvenile stage responsible for most Lyme disease transmission) are actively seeking hosts. These nymphs are roughly the size of a poppy seed, making them easy to miss on your skin.
New Jersey’s Lyme disease case reports reflect this pattern clearly. State health data from 2022 to 2024 shows case numbers climbing sharply in late spring, peaking in June and July, then tapering through fall. The state averages about 69 cases per 100,000 residents annually, placing it among the highest-risk states in the country.
The Asian longhorned tick, an invasive species that has established itself across New Jersey, has an even wider active window: March through October. This species prefers tall grasses, meadows, pastures, and transitional areas where forest meets open fields. Soccer fields bordering woods are a common hotspot. While these ticks rarely bite people, they can produce itchy larval infestations in fall that resemble chigger bites, and they pose a serious threat to dogs and livestock.
Why Mild Winters Don’t Mean Safety
Ticks don’t die off in winter. They become dormant when temperatures drop below freezing but can reactivate on any day the ground temperature exceeds 45°F. In a state like New Jersey, where January and February regularly produce warm spells in the 50s, ticks can emerge and quest for hosts during what most people consider the off-season. A hike on a sunny 50-degree day in February carries real, if lower, tick risk.
Tick-Borne Diseases in New Jersey
Lyme disease gets the most attention, but it’s far from the only tick-borne illness circulating in New Jersey. The state’s Department of Health tracks nine tick-borne conditions: Lyme disease, anaplasmosis, babesiosis, ehrlichiosis, spotted fever rickettsiosis (which includes Rocky Mountain spotted fever), Powassan virus, tularemia, Borrelia miyamotoi infection, and alpha-gal syndrome, a meat allergy triggered by lone star tick bites.
Several of these are transmitted by the same blacklegged tick that carries Lyme, which means a single bite can potentially deliver more than one infection. Babesiosis and anaplasmosis are the most common co-infections, and they peak during the same summer months as Lyme.
What to Do After a Tick Bite
If you find an attached blacklegged tick and it appears engorged with blood (suggesting it’s been feeding for 36 hours or more), a single dose of the antibiotic doxycycline can lower your risk of developing Lyme disease. This prophylactic treatment is most effective when started within 72 hours of removing the tick. It applies specifically to blacklegged tick bites in high-incidence areas like New Jersey, where infection rates in ticks are well above the 20% threshold that triggers this recommendation.
Not every tick bite warrants antibiotics. The key factors are the species of tick (blacklegged ticks carry Lyme; dog ticks and lone star ticks do not), how long it was attached, and how quickly you can start treatment. Save the tick in a sealed bag if possible, since identification matters for determining your risk.
Protecting Yourself During Peak Season
Repellents and treated clothing are your two main tools. For skin, products containing DEET, picaridin, oil of lemon eucalyptus (OLE), or IR3535 all provide effective protection. Higher concentrations last longer: anything under 10% active ingredient typically protects for only one to two hours. DEET’s effectiveness peaks around 50% concentration, so there’s no benefit to going higher than that.
For clothing, permethrin is the standout. At 0.5% concentration, permethrin-treated clothing actively kills ticks, mosquitoes, and chiggers on contact. You can buy pre-treated gear or spray your own shoes, pants, socks, and hats. Treated items need 24 to 48 hours to dry before use. Permethrin goes on clothing only, not skin.
Beyond chemical protection, a few habits make a real difference during April through September. Stick to the center of trails when hiking. Tuck pants into socks in grassy or wooded areas (it looks ridiculous and works). Do a full-body tick check when you come inside, paying close attention to your hairline, behind your ears, armpits, groin, and behind your knees. Toss worn clothes in the dryer on high heat for 10 minutes, since the heat kills ticks that regular washing may not. Shower within two hours of being outdoors, which helps wash off unattached ticks and gives you a chance to spot any that have latched on.
Highest-Risk Habitats in New Jersey
Ticks in New Jersey aren’t confined to deep woods. They thrive in leaf litter, tall grass, shrubby edges, and the transitional zones between forests and open areas. Your backyard can be prime tick habitat if it borders woods or has overgrown areas with leaf debris. Stone walls, groundcover plants, and woodpiles near your home create the humid, shaded microenvironments that ticks need to survive.
Suburban yards in northern and central New Jersey carry particularly high risk, given the dense deer populations that sustain adult blacklegged ticks. Keeping your lawn mowed, clearing leaf litter, and creating a three-foot gravel or wood chip barrier between your lawn and any wooded edge can significantly reduce the number of ticks in your yard.