Quick Answer
Tick season is not a date on the calendar — it is a temperature threshold. Most ticks become active when sustained daily temperatures hold above 35–40°F (2–4°C). In the Deep South and Gulf Coast, that means ticks never fully stop; activity is near year-round. In the Northeast and upper Midwest, the window typically opens in March or April and closes in November. The lone star tick activates earlier and stays active longer than the deer tick across most of its range. For the majority of Americans east of the Rockies, the practical answer is: ticks are active from early spring through late fall — and you should be protecting yourself before they peak, not after your first bite.
The tick doesn't care what month it is. It cares about temperature.
That single fact explains why people who move from Phoenix to Pennsylvania get blindsided, why hunters in Virginia are pulling ticks off in February, and why the standard advice to "watch out for ticks in summer" misses the actual window by four to six weeks on both ends.
This guide covers when ticks become active in every major US region, when each region peaks, which species you are dealing with, and — most practically — when to start applying protection so you are not making reactive decisions after a bite.
This article is for informational purposes only. If you have been bitten by a tick and are experiencing symptoms, contact a healthcare provider promptly.
Why Tick Season Is Temperature-Driven, Not Date-Driven
Tick activity is governed by one primary variable: temperature, specifically the 10-day rolling average in the air at ground level where ticks quest. Each species has a different cold-activity floor:
- Blacklegged (deer) tick (Ixodes scapularis): adults remain active whenever temperatures are above approximately 35–40°F (2–4°C). This is the tick that is famously active during winter thaws in the Northeast — it does not need spring to wake up, it just needs a stretch of days above freezing.
- Lone star tick (Amblyomma americanum): adults and nymphs become active in the mid-40s°F (~7–8°C) for adults, slightly warmer for larvae. In the South, this means they are active most of the year. In northern expansion states, they appear in late March or April.
- American dog tick (Dermacentor variabilis): somewhat more temperature-sensitive; typically active April through August in northern states, extending through fall further south.
- Gulf Coast tick (Amblyomma maculatum): warm-weather specialist, most active May through August in coastal southern states.
What this means in practice: there is no single national "tick season." There are regional tick windows, and in the South there is no off-season worth counting on. CDC tick phenology research consistently shows that tick encounter rates track 2–3 weeks behind sustained temperature shifts — meaning the first warm week of spring is not peak risk. The second and third weeks are.
Climate change is extending these windows. A CDC analysis of tick surveillance data from 2004–2018 found that the established range of both the blacklegged tick and the lone star tick expanded significantly, with northern range boundaries advancing at rates consistent with observed warming trends. In states like Minnesota, Wisconsin, and Maine, ticks are now active weeks earlier in spring and weeks later in fall than they were two decades ago.
US Tick Season by Region: The Data Table
The table below draws from CDC tick phenology data, state health department surveillance programs (including NY DOH, NJ DOH, VA DOH, and NC DHHS), and published phenological research on tick life cycle timing. "Active season" represents the typical window when human encounter rates are elevated. "Peak weeks" are when nymph and adult activity are highest and bite risk is greatest.
| Region | Typical Active Season | Peak Weeks | Primary Tick Species | Key Diseases |
|---|---|---|---|---|
|
Northeast ME, NH, VT, MA, RI, CT, NY, PA, NJ |
Late March – November (deer tick adults also active Nov–Mar on warm days) |
May–July (nymphs) Oct–Nov (adults) |
Blacklegged tick (dominant) Lone star tick (expanding) American dog tick |
Lyme disease, anaplasmosis, babesiosis, Powassan virus, alpha-gal syndrome (expanding) |
|
Mid-Atlantic MD, DE, VA, WV, DC |
March – November | April–July; second peak Sep–Oct | Lone star tick (dominant) Blacklegged tick American dog tick |
Alpha-gal syndrome, ehrlichiosis, Lyme disease, Rocky Mountain spotted fever |
|
Southeast / Gulf Coast NC, SC, GA, FL, AL, MS, LA |
Year-round (brief lull Dec–Jan in northern parts) |
March–August (peak intensity) | Lone star tick (dominant) American dog tick Gulf Coast tick Blacklegged tick |
Alpha-gal syndrome, ehrlichiosis, RMSF, tularemia, Heartland virus |
|
South-Central TX, OK, AR, MO, KS |
February – November (year-round in southern TX) |
April–September | Lone star tick (dominant) American dog tick Brown dog tick |
Alpha-gal syndrome, ehrlichiosis, RMSF, tularemia, Bourbon virus |
|
Midwest / Great Plains OH, IN, IL, MI, WI, MN, IA, NE, SD, ND |
April – October | May–July (nymphs); Oct (adults) | Blacklegged tick (northern) Lone star tick (southern/expanding) American dog tick |
Lyme disease, anaplasmosis, ehrlichiosis (expanding), RMSF |
|
Mountain West CO, UT, WY, MT, ID, NM, AZ, NV |
April – September (elevation-dependent; lower elevations start earlier) |
May–August | Rocky Mountain wood tick American dog tick Western blacklegged tick |
Rocky Mountain spotted fever, Colorado tick fever, tick paralysis, tularemia |
|
Pacific Coast CA, OR, WA |
March – October (year-round in coastal CA) |
April–July | Western blacklegged tick Pacific Coast tick American dog tick |
Lyme disease (western variant), anaplasmosis, RMSF, tick paralysis |
Sources: CDC Division of Vector-Borne Diseases tick surveillance; CDC tick geographic distribution data; New York State Department of Health tick surveillance; New Jersey DOH tick-borne disease program; Virginia Department of Health tick-borne disease surveillance; North Carolina DHHS tick-borne disease epidemiology data; published phenological research (Diuk-Wasser et al., Journal of Medical Entomology; Ogden et al., PLOS ONE climate projections).
Region-by-Region Breakdown
Northeast (ME, NH, VT, MA, RI, CT, NY, PA, NJ)
The Northeast has one of the country's most complex tick pictures: the blacklegged deer tick dominates and is active nearly year-round in adults, with nymphs surging May through July. Nymphs are the most dangerous life stage for Lyme transmission — they are poppy-seed sized, hard to detect, and at their peak precisely when trail use is highest. CDC Lyme disease surveillance data consistently shows the Northeast as the highest-incidence region in the country, with a dense concentration in coastal New England and the New York–New Jersey–Connecticut corridor.
The lone star tick is no longer a visitor in the Northeast — it is establishing permanent populations. See the 2026 range expansion data here. For residents and visitors, this means the bite-risk calculus now includes both Lyme disease and alpha-gal syndrome — two distinct threats requiring the same prevention response.
When to start protection in 2026: Mid-March or earlier during mild years. Do not wait for the calendar to read "May."
Mid-Atlantic (MD, DE, VA, WV, DC)
The Mid-Atlantic is lone star tick country, full stop. Virginia's state health department tracks lone star tick bites from late February onward in the Piedmont and coastal plain regions. This is the heart of the alpha-gal syndrome and ehrlichiosis belt — diseases the lone star tick transmits and the blacklegged tick does not. The mix of deer tick (Lyme risk) and lone star tick (AGS, ehrlichiosis risk) in the same woodland habitats makes the Mid-Atlantic one of the higher-risk zones in the US for tick-borne illness overall.
When to start protection in 2026: Early March if you are anywhere near wooded or brushy terrain. Virginia DOH surveillance regularly documents human tick encounters in the first week of March during normal years.
Southeast / Gulf Coast (NC, SC, GA, FL, AL, MS, LA)
There is no real off-season in the Southeast. January is the lightest month for tick activity, and even then, North Carolina's tick surveillance program documents encounters in every month of the year. The lone star tick peaks in late spring through summer, but adult ticks remain active through November and into December in most of the region. Florida and coastal Louisiana see meaningful lone star tick activity even in winter months.
When to start protection in 2026: Year-round is the correct answer. If you are being practical, February at the latest — before the spring surge.
South-Central (TX, OK, AR, MO, KS)
Texas has the longest tick season in the contiguous US. Lone star ticks are active in the eastern and central parts of the state from February through November, and in south Texas near year-round. Oklahoma and Arkansas mirror this timeline closely. The South-Central region is also the core range for Bourbon virus and Heartland virus, emerging tick-borne pathogens with no specific antiviral treatment that are both transmitted by the lone star tick.
When to start protection in 2026: February in Texas and Oklahoma. March in Missouri and Kansas.
Midwest / Great Plains (OH, IN, IL, MI, WI, MN, IA, NE, SD, ND)
The Midwest is experiencing a genuine tick expansion — both the blacklegged tick and the lone star tick have pushed north and west into states that did not have established populations fifteen years ago. Minnesota's Department of Health documents blacklegged tick populations now established in over 50 counties. Wisconsin's surveillance program shows similar northward creep. In the southern tier (Ohio, Indiana, Illinois), lone star ticks are now established and contributing to ehrlichiosis and alpha-gal syndrome case counts that were negligible a decade ago.
When to start protection in 2026: April for most of the region; late March in southern Ohio, Indiana, and Illinois.
Mountain West (CO, UT, WY, MT, ID, NM, AZ, NV)
The Mountain West tick picture differs from the East: the dominant medical threat here is Rocky Mountain spotted fever (RMSF) from the Rocky Mountain wood tick and American dog tick — a disease that, untreated, kills faster than Lyme. Tick season is strongly elevation-dependent: valley floors and lower foothills see activity starting in April, while high-alpine terrain may not see active ticks until June. Overall tick diversity and encounter frequency is lower than the East, but individual bites carry a higher per-bite risk of serious disease from RMSF.
When to start protection in 2026: April for anyone spending time at lower elevations; May for most recreational use.
Pacific Coast (CA, OR, WA)
The western blacklegged tick (Ixodes pacificus) is the primary Lyme vector on the Pacific Coast, but infection rates in ticks are notably lower than in eastern Ixodes scapularis populations — roughly 1–2% of western blacklegged ticks carry Borrelia burgdorferi compared to 20–30% in the Northeast. That is not a reason for complacency; it changes the per-bite probability, not the outcome of an infected bite. Coastal California sees near-year-round activity in the coastal ranges; Oregon and Washington have a more defined spring–fall window.
When to start protection in 2026: March in California; April in Oregon and Washington.
State Spotlights: Tick Season Start Dates for High-Risk States
These states account for the majority of tick-borne illness reports in the US. If you live in or are traveling to one of them, these are the specific dates and threats to know.
New York — Tick Season Start: Late March (Long Island); April (Upstate)
Suffolk County on Long Island is among the highest-density Lyme disease counties in the country and is considered an epicenter for alpha-gal syndrome in the Northeast. Blacklegged ticks are active from late March; lone star ticks (confirmed on Long Island) overlap from April through October. NYSDOH tick surveillance documents lone star tick activity increasing year over year on Long Island. Start tick prevention: mid-March.
New Jersey — Tick Season Start: March
New Jersey is one of the most Lyme-endemic states in the country. Blacklegged ticks are active from March; lone star ticks (established throughout the state) overlap from April. NJDOH reports two to three times the national average rate of Lyme disease diagnoses. The Pinelands and suburban-woodland interfaces are particularly high-exposure areas. Start tick prevention: early March.
Connecticut — Tick Season Start: March (Lyme disease was named here)
Connecticut is where Lyme disease was first characterized in the 1970s — the town of Lyme, Connecticut gave the disease its name. Blacklegged tick density in the state remains among the highest in the nation. Active from March through November, with peak nymph activity in May and June. Start tick prevention: March.
Virginia — Tick Season Start: March (Northern VA); February (Southwest VA)
Virginia is a high-exposure state for both Lyme (blacklegged tick, statewide) and alpha-gal syndrome (lone star tick, statewide). The Charlottesville/UVA area is home to Dr. Scott Commins' alpha-gal research program — meaning AGS case diagnosis is unusually high there partly due to clinical recognition, not just tick density. Shenandoah Valley and the Blue Ridge are year-round active zones. Start tick prevention: early March in Northern VA; late February in Southwest VA.
Pennsylvania — Tick Season Start: March (Southeast PA); April (North/West)
Pennsylvania has among the highest total Lyme disease case counts of any US state in absolute numbers. Blacklegged ticks are established statewide; lone star ticks are expanding northward from the southeast counties. The Pocono Mountains, Appalachian ridges, and forested suburban areas around Philadelphia are high-exposure zones. Start tick prevention: late February in Southeast PA; April elsewhere.
Maryland — Tick Season Start: March
Maryland is fully within the blacklegged tick and lone star tick overlap zone. Eastern Shore counties have particularly high lone star tick density; Baltimore and DC-area suburbs have high blacklegged tick exposure. Start tick prevention: early March.
Tennessee — Tick Season Start: February (Memphis/Nashville area); March (East TN)
Tennessee sits at the heart of the lone star tick's established range. Alpha-gal syndrome rates are among the highest in the country here, driven by high lone star tick density from February through November. Western Tennessee has documented lone star tick activity even in mild January periods. Start tick prevention: February in Western and Middle Tennessee; March in the mountains.
Texas — Tick Season Start: February (East/Central TX); March (Panhandle)
Eastern Texas and the Hill Country are lone star tick epicenters. Central Texas (Austin, San Antonio corridor) sees active lone star ticks from late February; East Texas is effectively year-round in its southernmost counties. The Hill Country specifically sees concentrated lone star tick activity that extends longer into fall than most of the state. Start tick prevention: February across most of Texas.
Minnesota — Tick Season Start: April (South/Central MN); May (North MN)
Minnesota has seen a dramatic increase in Lyme disease cases over the past decade as blacklegged ticks have colonized new counties each year. The Minnesota Department of Health now considers roughly the southern two-thirds of the state endemic for Lyme. Lone star ticks have been confirmed in southern Minnesota counties. Start tick prevention: early April in the Twin Cities metro and southern MN; May in the North Woods.
Florida — Tick Season: Year-Round
Florida has no reliable tick dormancy period. Lone star ticks, American dog ticks, and Gulf Coast ticks are active year-round in most of the state. Northern Florida counties see slightly reduced activity in January and February, but "reduced" does not mean "absent." If you are hiking, hunting, or spending time outdoors in Florida, apply tick prevention every time regardless of the calendar month. Tick prevention: year-round, no off-season.
The Year-Round Risk in Southern States
The "tick season" framing actively misleads people in the South. There is no month in Florida, Louisiana, coastal Georgia, or south Texas where lone star ticks are reliably dormant. State health departments in all four states document tick-borne illness cases every month of the year, with January and February as the lightest months in terms of case counts — not zero-risk months.
What changes in the South is not "on or off" — it is relative intensity. The peak surge of nymph activity in May and June in Virginia or North Carolina is a real escalation above the winter baseline. But the winter baseline is not zero. It is "lower than peak, still real."
For people who moved to the South from northern states: your instinct to relax tick prevention in October and restart it in April is correct behavior for a northeastern tick calendar. It is the wrong behavior for the South. If you are in the Southeast and you stop protecting yourself after Labor Day, you are skipping the late-fall adult surge — which, for lone star ticks, runs October through December across much of the region.
The practical protocol for Gulf Coast states, Florida, and south Texas: year-round protection. Choose a routine and keep it.
State Spotlight
Suffolk County, Long Island — The Alpha-Gal and Lyme Disease Epicenter
Suffolk County, New York consistently ranks among the highest Lyme disease incidence counties in the United States. The combination of dense hardwood forest habitat, a massive white-tailed deer population, and proximity to millions of suburban and exurban residents creates conditions for tick exposure at a scale found nowhere else in the Northeast.
In 2026, the picture has compounded: lone star ticks — previously uncommon on Long Island — are now established in Suffolk County's south-shore and central pine barrens habitats. This means Long Island residents face simultaneous risk from both blacklegged tick–transmitted Lyme disease and lone star tick–transmitted alpha-gal syndrome in the same backyards, trail systems, and golf course rough.
The Suffolk County Department of Health Services runs one of the country's most active tick surveillance programs. Their data shows blacklegged tick nymph activity beginning as early as late April in warm years, peaking in late May through mid-June. Lone star tick nymph activity follows approximately two to three weeks later.
Suffolk County start date for 2026: Apply protection beginning no later than April 15. If you are hiking, gardening, or walking a dog near any wooded or brushy terrain — that means every time, from mid-April through November.
When to Start Tick Prevention: Lead the Season
The single most common mistake tick-aware people make: they start protecting themselves after their first bite of the year, or after the first news story about tick season. Both are reactive. Both are too late.
The reason to start early matters: protection from a CDC-recommended repellent works on contact, but the habit of applying it before going outside — not after you notice something moving on your ankle — takes a week or two to become automatic. Starting two weeks before your first anticipated outdoor exposure in tick country means your protection routine is already running by the time tick activity spikes.
The regional start calendar for 2026, based on typical season-opening temperature patterns:
- Southeast, Gulf Coast, south Texas: Year-round. If you stopped, restart now.
- Mid-Atlantic (VA, MD, DE, WV): No later than March 1
- Northeast (NY, NJ, PA, CT): No later than March 15; early April for Maine, Vermont, New Hampshire
- South-Central (TX, OK, AR, MO): February for southern areas; March for northern
- Midwest (OH, IN, IL, MI): Late March to early April
- Upper Midwest (WI, MN, IA): April 1 – April 15
- Mountain West: April for valley areas; May for higher elevations
- Pacific Coast (CA, OR, WA): March for California; April for Oregon and Washington
These dates assume you are outdoors regularly — walking a dog, gardening, hiking, hunting, or living near wooded terrain. If you are driving to a trailhead once a month, adjust accordingly. But note: the yard is tick habitat. The dog brings ticks inside. The risk calculus for suburban families with any wooded or brushy yard nearby is not "only when hiking." It is "anytime outdoors."
Climate Change and the Extending Season
The tick season table above represents 2026 conditions. It is not the permanent state. Every year since the mid-1990s, CDC surveillance data shows the effective tick season expanding at both ends in most of the country — earlier in spring, later in fall, and with northern range boundaries advancing.
The mechanism is straightforward. Blacklegged ticks and lone star ticks require sustained cold to kill off overwintering populations. As mild winters become more frequent, tick survival over winter improves and spring emergence happens earlier. Migratory birds carry tick larvae and nymphs to new latitudes — white-crowned sparrows, gray catbirds, and American robins have all been identified as significant tick dispersal vectors in published ornithological studies. When those birds carry ticks to regions with now-warmer winters, the ticks can establish rather than die out.
The practical implication: if the tick season in your area seems to be starting earlier than it used to, you are not imagining it. CDC surveillance data supports that perception with county-level documentation across all major tick species.
For planning purposes, the conservative assumption is to treat the season as two to three weeks longer on each end than the decade-old regional norms suggested — and to watch state health department updates in your county for current-year data.
Practical Protocol: Start Early, Apply Every Time
The prevention protocol does not change by region — only the start date and the stop date change. The protocol itself is consistent:
- Apply a CDC-recommended tick repellent to all exposed skin before going outside. For adults and children 3 and up, OLE/PMD (Oil of Lemon Eucalyptus / p-menthane-3,8-diol) at 30% is the only plant-based active on the CDC's list with peer-reviewed tick efficacy data. It provides approximately six hours of protection per application. DEET (20–30%), picaridin (20%), and IR3535 are also CDC-recommended. Choose one and use it consistently.
- Treat clothing and gear with permethrin. Permethrin kills ticks on contact and remains effective through 40–50 wash cycles on treated garments. Long pants tucked into treated socks create a ground-level barrier specifically effective against lone star ticks and deer tick nymphs, both of which approach from below.
- Do a full-body tick check within two hours of coming indoors. Every time. Check: hairline and scalp, behind ears, neck, armpits, chest, under arms, groin, behind knees, between toes. Check children and pets.
- Protect your pets year-round in tick country. A tick that rides indoors on a dog or cat can detach and seek a human host. Pet protection is not separate from human protection — it is part of the same household defense layer. See the full Lyme disease prevention guide for household tick reduction strategies.
- Shower within two hours of outdoor exposure. This washes off unattached ticks and makes it easier to find attached ones before they have time to transmit pathogens.
The repellent only works when it is on your skin before you go out. Not after. The tick that gives you alpha-gal syndrome, Lyme disease, or ehrlichiosis does not announce itself — it is the one you did not notice. Apply first, check after, and treat the routine as non-negotiable from the first warm week of spring through the first hard freeze of fall.
In the South: there is no first hard freeze to wait for. Year-round is the protocol.
Tick season is already open in most of the country
Start protecting your family before the peak.
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Not a guarantee against tick-borne illness. Repellents reduce bite risk — always combine with tick checks and treated clothing for comprehensive protection.
Sources: CDC Division of Vector-Borne Diseases tick surveillance and geographic distribution data (cdc.gov/ticks); CDC Lyme disease surveillance statistics; New York State Department of Health tick surveillance program; New Jersey Department of Health tick-borne disease surveillance; Virginia Department of Health tick-borne disease epidemiology; North Carolina DHHS Communicable Disease Branch tick-borne illness data; Suffolk County Department of Health Services tick surveillance; Diuk-Wasser MA et al., "Field and climate-based model for predicting the density of host-seeking nymph Ixodes scapularis," Journal of Medical Entomology; Ogden NH et al., "Climate change and the potential for range expansion of the Lyme disease vector Ixodes scapularis in Canada," International Journal for Parasitology. This article provides educational information only and is not a substitute for professional medical or veterinary advice.