2026 Tick Season Alert: Why This Year Is Worse for Westchester Homeowners

What the 2026 Data Is Already Showing

Every spring, Westchester County health officials and pest professionals watch several indicators to project tick season severity. In 2026, every major signal is pointing in the same direction — toward higher tick populations, earlier emergence, and expanded geographic range compared to prior years.

Orkin's annual Mosquito Cities List ranked New York third in the country for 2026, citing increased risk of mosquito-borne illness alongside an "itchy summer ahead." While the Orkin ranking focuses on mosquitoes, it is built on the same underlying conditions that drive tick activity: warm, humid spring weather, mild winter temperatures, and abundant wildlife host populations. New York's climb to third nationally reflects a regional shift in vector pressure that extends directly to ticks in Westchester County.

The New York Times reported just one week ago that 2026 is "already a bad tick season" — a phrase that entomologists use carefully. It reflects field counts and early-season Lyme disease case reports, not predictions. The NY Post characterized the spring's combined tick and mosquito outlook as a "perfect storm" driven by warming winters and rainfall patterns that expand and sustain tick habitat well beyond traditional forest edges.

For Scarsdale homeowners, these national and regional signals are not abstractions. Westchester County already ranks among the highest-incidence counties for Lyme disease in the United States. A year when every trend indicator moves in the wrong direction demands earlier, more aggressive personal and property-level action than homeowners may be used to.

The Longhorned Tick: A New Threat in Westchester

Native blacklegged ticks (deer ticks) and American dog ticks are the established tick species in Westchester County. But in 2026, a third species demands attention: the longhorned tick (Haemaphysalis longicornis), an invasive species that ABC7 NY confirmed is now present in Westchester County.

The longhorned tick originated in East Asia and was first detected in the United States in New Jersey in 2017. It has since spread across the Mid-Atlantic and Northeast. What makes it distinctly alarming compared to native ticks is its reproductive strategy: longhorned ticks are parthenogenetic, meaning females can reproduce without mating. A single female that reaches a new habitat can establish a population alone. The result is that longhorned tick populations build rapidly and can infest a host — including humans, pets, deer, and livestock — in numbers far exceeding anything seen from native species.

The disease transmission risk of longhorned ticks to humans in the U.S. is still under active research. In Asia, longhorned ticks transmit Severe Fever with Thrombocytopenia Syndrome (SFTS) virus — a serious hemorrhagic fever. No confirmed SFTS transmission to humans has been documented in the U.S. to date, but the CDC is actively monitoring for it. What is confirmed is that longhorned ticks can carry and transmit spotted fever group Rickettsia bacteria.

For Westchester homeowners, the immediate concern is volume: a property edge or deer trail that previously hosted dozens of blacklegged tick nymphs can now host thousands of longhorned ticks in an established population. Standard tick checks after outdoor activity, while always essential, become more demanding when tick densities reach this scale. Our LymeShield tick and mosquito program accounts for both native and invasive tick species in its treatment approach.

Why Mild Winters Set Records for Tick Populations

The 2025–2026 winter across the Northeast was notably mild. Extended cold snaps — particularly sustained temperatures below 10°F over multiple consecutive days — are the primary natural mechanism that suppresses overwintering tick populations. When winters fail to deliver those events, ticks that would otherwise die survive in greater numbers and emerge earlier in spring.

Cornell University Cooperative Extension data shows that mild winters correlate with tick nymph emergence that is two to three weeks earlier than in colder years. In practical terms, this means that nymph-stage blacklegged ticks — the stage responsible for the majority of Lyme disease transmission because of their small size and long feeding times — are already active and questing in Westchester this week.

The nymph stage is the highest-risk period of the tick life cycle. Nymphs are the size of a poppy seed. They are easy to miss during tick checks, they feed for longer periods than adults, and in Westchester County, infection rates in nymph populations have reached 30–50% in some surveyed areas according to Westchester County Department of Health data. A single bite from an infected nymph is sufficient to transmit Lyme disease if the tick feeds for more than 36 hours.

If you have been deferring your first tick control treatment of the season, the mild winter data suggests that window has already passed. To understand what a complete season protection plan looks like, our guide on when to start tick prevention in the Hudson Valley walks through the timing week by week.

The High-Risk Zones in Scarsdale and Westchester

Not all areas of a property carry equal tick risk, and not all neighborhoods in Westchester carry identical exposure. Understanding where risk concentrates helps prioritize both personal protection and professional treatment areas.

At the property level, the highest tick densities are found in the transitional zone between maintained lawn and wooded or brushy areas — called the ecotone. Ticks do not thrive in short, dry, sunny lawn; they concentrate in leaf litter, tall grass, and brush where humidity stays high and hosts (deer, mice, rabbits) move through regularly. In Scarsdale's residential landscape — large lots, wooded property edges, stone walls, and mature ornamental plantings — these transitional zones are frequently found just steps from patios and play areas.

Deer are the primary reproductive host for adult blacklegged ticks. In neighborhoods where deer movement is high — including much of the Heathcote, Greenacres, and Fox Meadow sections of Scarsdale — tick pressure on properties along deer corridors is measurably higher than in areas with less deer access. Deer-attracting landscaping features (fruit trees, bird feeders, low ornamentals) positioned near the property edge increase exposure further.

For the longhorned tick specifically, surveyed populations in the Northeast have concentrated along deer trails, in meadow areas adjacent to forest, and in locations where livestock or white-tailed deer pass regularly. If your property or adjacent open space shows high deer activity, longhorned tick monitoring should be part of your 2026 plan.

What to Do Right Now (May Through July)

The window between now and late July is the period of highest Lyme disease transmission risk in Westchester. Here is a prioritized action list for the next 60 days:

This week: Walk your property perimeter and yard edge. Look for leaf litter accumulation, tall grass, and brushy areas within 10 feet of areas where children or pets spend time. Clear what you can — ticks need humidity and do not survive in short, exposed grass. Create a 3-foot wood chip or gravel barrier between lawn and wooded edges if possible.

This month: Schedule a professional tick control application if you have not done so. The first application of the season — typically a targeted barrier treatment applied to the tick habitat zones identified above — should happen by mid-May. For properties with known deer pressure or adjacent wooded areas, a second application in late June extends protection through the nymph peak. Our LymeShield program structures these applications into a coordinated seasonal plan.

Every day outdoors: Wear light-colored clothing so ticks are visible, tuck pants into socks, apply EPA-registered repellent (DEET 20–30% or permethrin on clothing), and perform a full-body tick check within two hours of coming indoors. Pay particular attention to the scalp, behind the ears, armpit area, behind the knees, and the groin — areas where nymphs frequently attach and are easily missed.

Know the symptoms: The bullseye rash (erythema migrans) appears in approximately 70–80% of Lyme cases, but not all. Early Lyme symptoms also include fatigue, fever, headache, and muscle aches. If you have had a tick attached for more than 24 hours and develop any of these symptoms within 30 days, contact your physician promptly. Early treatment with antibiotics is highly effective. Delayed treatment is significantly more complex. For a detailed review of Lyme disease symptoms and what Westchester residents need to know, our full guide covers the clinical picture and the co-infections that can occur alongside Lyme.

For a complete personal protection plan with seasonal timing, see our dedicated tick prevention guide for New York homeowners — built specifically for the Westchester County risk profile.

FAQ: 2026 Tick Season in Westchester County

When does tick season peak in Westchester County?

In Westchester County, blacklegged tick nymphs peak from mid-May through July — the period of highest Lyme disease transmission risk. Adult ticks remain active in fall (October–November) and can bite on any day when temperatures stay above 35°F, which in recent mild winters includes much of December. There is no true off season for tick activity in this region anymore.

What is the longhorned tick and is it in Westchester?

The longhorned tick (Haemaphysalis longicornis) is an invasive species first confirmed in New Jersey in 2017. It has since spread across the Northeast, and ABC7 NY confirmed its presence in Westchester County. Unlike native ticks, the longhorned tick can reproduce without mating and can infest a host in massive numbers. Its disease transmission risk in the U.S. is still under active research, but its sheer population density poses a significant nuisance and potential health concern.

Does a mild winter really mean more ticks in spring?

Yes. Tick survival through winter is directly tied to temperature. Extended cold snaps (sustained temperatures below 10°F) reduce overwintering tick populations. The 2025–2026 winter across the Northeast was notably mild, with fewer extended cold events than prior years. Research from Cornell University Cooperative Extension confirms that mild winters correlate with higher tick survival rates and earlier spring emergence — typically two to three weeks earlier than in colder winters.

How do I reduce tick risk on my Westchester property?

The most effective property-level steps are: mow grass short and clear leaf litter from yard edges, create a 3-foot wood chip or gravel barrier between lawn and wooded areas, remove deer attractants from the yard perimeter, and schedule professional tick control treatments in April and again in late June. Personal protection — wearing light-colored clothing, tucking pants into socks, and performing daily tick checks — remains essential regardless of property treatment status.

What diseases do ticks carry in Westchester County?

The blacklegged tick in Westchester County can transmit Lyme disease, Babesiosis, Anaplasmosis, and Powassan virus. Lyme disease is by far the most common — Westchester County consistently ranks among the highest-incidence counties in the U.S. Babesiosis and Anaplasmosis are co-infections that can occur alongside Lyme and complicate diagnosis. The American dog tick, also present in the region, can transmit Rocky Mountain Spotted Fever.