Are ticks active in winter?

Yes, at least partially. Unlike mosquitoes and wasps, ticks do not die at the first frost. According to NH DHHS, ticks are active any time the outside temperature is above 40°F and they are not covered by snow. That means a mild, snow-free stretch in December, January, or February can still produce questing ticks and bite risk, even though overall activity is much lower than the May–July and October peaks. Snow cover offers real protection, but a warm winter with little snow keeps ticks more active than homeowners expect.

When is Lyme season / risk highest in NH?

Lyme risk in New Hampshire is highest in June and July, the peak months for nymphal blacklegged ticks, according to UNH Extension and NH surveillance data. Nymphs emerge around May 15 and remain active through mid-July, and because they are roughly the size of a poppy seed, they're easy to miss on skin and clothing, which lets them stay attached long enough to transmit disease. A smaller secondary risk period comes in fall, when larger, more visible adult ticks are active from early October through late November.

Which tick stage is most dangerous?

Nymphs are the most dangerous life stage of the blacklegged tick in New Hampshire. They measure under 2 millimeters — about the size of a poppy seed — making them far harder to spot than adult ticks, according to NH DHHS. Because they often go unnoticed on skin or clothing, nymphs stay attached longer and are responsible for most Lyme disease transmission in the state. Their peak activity window, May 15 through mid-July, is why late spring and early summer are the highest-risk months for tick-borne illness in NH, even though adult ticks are larger and more visible.

How long does a tick have to be attached to transmit Lyme?

Transmission risk rises the longer a tick stays attached. Removing an attached tick within roughly 24 hours can prevent Lyme disease transmission, according to NH DHHS and CDC guidance. However, other tick-borne pathogens move faster — anaplasmosis and Borrelia miyamotoi can transmit within 24 hours, and Powassan virus has been documented transmitting in as little as 15 minutes. Because of this, prompt removal with tweezers after any outdoor exposure matters regardless of how long the tick appears to have been attached. Watch the bite site and your overall health for 30 days, and see a physician if fever or an expanding rash develops.

How common is Lyme disease in NH?

Lyme disease is very common in New Hampshire. The state reported 1,085 cases in 2022, an incidence rate of 78.8 per 100,000 people — above the 2022 median of 68.3 per 100,000 among the 15 CDC-designated high-incidence jurisdictions, according to the CDC's MMWR (February 2024). NH is one of the states where Lyme is considered endemic, driven by a blacklegged tick population in which roughly 60% of sampled ticks carry the Lyme-causing bacterium, Borrelia burgdorferi, according to NH DHHS. Reported cases likely undercount true infections nationally.

What other diseases do NH ticks carry?

Beyond Lyme disease, New Hampshire's blacklegged tick population carries several other pathogens homeowners should know about, according to NH DHHS: anaplasmosis, babesiosis, Powassan virus, and Borrelia miyamotoi. These diseases vary in how quickly they transmit after a bite — Powassan virus can transmit in as little as 15 minutes of attachment, far faster than the roughly 24-hour window often cited for Lyme. Symptoms across these illnesses can include fever, chills, headache, and fatigue; because they can be serious, any fever or unusual illness following a tick bite warrants a call to a physician rather than a wait-and-see approach.

Is the lone star tick in New Hampshire?

Yes. The CDC confirmed the presence of the lone star tick in New Hampshire as of 2020, and the species is continuing to expand north into New England, according to Tick Free NH. Historically more common in the southeastern and mid-Atlantic United States, the lone star tick is now an established concern for NH homeowners alongside the longer-established blacklegged (deer) tick and American dog tick. It's identifiable by the single white dot on the back of adult females. Its northward expansion is one more reason tick precautions in NH now need to run essentially year-round rather than just in summer.

When should I treat my yard for ticks in NH?

The most effective yard-treatment timing follows the tick life cycle. UNH Extension recommends an early-June acaricide or leaf-litter barrier treatment specifically to control nymphs during their peak window. A mid-May treatment also helps against American dog ticks, and an October application targets the fall adult surge. In spring, build a tick-safe zone with a 3-foot wood-chip or gravel border between lawn and woods, keep grass short, and move woodpiles and bird feeders — which attract the mice that serve as a Lyme reservoir — away from the house.

What is the tick life cycle?

The blacklegged tick that spreads Lyme disease in New Hampshire has a two-year, three-host life cycle with four stages: egg, larva, nymph, and adult, according to UNH Extension. Each active stage — larva, nymph, and adult — must feed on a different host's blood before molting to the next stage or, for adults, laying eggs. This two-year span is why ticks overwinter multiple times before completing their cycle, and why a single warm winter or dry summer can shift the timing of the following year's nymph and adult peaks.

Daniel Brady · NH-Licensed Pesticide Applicator · License #782664

|Reviewed by Daniel Brady

When Are Ticks Most Active in NH? Tick & Lyme Timing

Seasonal Biters & Stingers

Ticks quest any day above about 40°F when there's no snow cover, so exposure is possible year-round in NH (NH DHHS). Activity is bimodal: adult blacklegged ticks peak in spring (late March–May) and again in fall (early October–late November), while nymphs peak May 15 through mid-July (UNH Extension). Nymphs drive most Lyme transmission because they're poppy-seed-sized and easy to miss. Roughly 60% of NH blacklegged ticks carry the Lyme bacterium (NH DHHS).

At a glance

Activity threshold: Any day above 40°F, snow-freeEffectively year-round, not just summer — NH DHHS
Adult activity (bimodal): Oct–late Nov & late Mar–MayBlacklegged tick adult peaks — UNH Extension
Nymph window: May 15–mid-JulyDrives most Lyme transmission; peak June–July — UNH Extension; NH DHHS
NH infection rate: ~60% of blacklegged ticks carry the Lyme bacteriumBorrelia burgdorferi — NH DHHS

Activity threshold
Any day above 40°F, snow-free
Effectively year-round, not just summer — NH DHHS
Adult activity (bimodal)
Oct–late Nov & late Mar–May
Blacklegged tick adult peaks — UNH Extension
Nymph window
May 15–mid-July
Drives most Lyme transmission; peak June–July — UNH Extension; NH DHHS
NH infection rate
~60% of blacklegged ticks carry the Lyme bacterium
Borrelia burgdorferi — NH DHHS

The timing answer

The short of it

The verdict · seasonal biters & stingers

Active year-round; nymph/Lyme peak now

Ticks are active any NH day above ~40°F — effectively year-round — but you're in the most dangerous stretch right now: nymph-driven Lyme risk peaks May–July.

NH activity calendar

When are they active — the whole year at a glance

Unlike mosquitoes and wasps, ticks never fully shut down in New Hampshire — they simply slow down in the cold and quest again on any mild, snow-free day.

12-month activity · New Hampshire

Peak · May, Jun, Jul, OctYou are here · Aug

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

PeakActiveBuildingDecliningDormantCurrent season · Summer

Best window to act · Early June acaricide/leaf-litter barrier treatment to yard edges targets blacklegged nymphs (UNH Extension); a mid-May treatment also hits American dog ticks; an October treatment targets fall adults. Build a tick-safe zone in April: a 3-foot wood-chip or gravel border between lawn and woods, short grass, and woodpiles/feeders moved away from the house.

What else peaks thenMay Jun Jul Oct

Unlike mosquitoes and wasps, ticks do NOT die at frost — they quest any day above ~40°F without snow, so winter cold is only partial relief. Nymph-driven Lyme risk peaks May–July; adults peak again Oct–Nov (NH DHHS / UNH Extension; frost anchor Manchester ~Oct 19, NOAA).

Season by season

A year in the life

Tick risk in New Hampshire is bimodal and never fully disappears, which sets it apart from the other pests in this cluster.

01
Spring
Adults quest first as snow melts in March, then nymphs emerge around mid-May. This is the window to start tick checks and yard management, and the best time to schedule a barrier treatment before the dangerous nymph season arrives.
02
Summer
The dangerous nymph season. Most Lyme, anaplasmosis, and babesiosis exposures happen here, peaking in June and July. Nymphs are poppy-seed-sized and easy to miss, so daily tick checks after outdoor time are essential.
03
Fall
Adult ticks surge again from early October through late November. Hunters, hikers, and gardeners face renewed bite risk well after mosquito and wasp seasons have ended for the year.
04
Winter
Ticks do not truly hibernate. Adults quest on any day above 40°F with no snow cover, so cold snaps offer only partial relief — a mild, low-snow winter can mean tick exposure even in January.

New Hampshire context

Ticks in southern New Hampshire

NH is a CDC-designated high-incidence Lyme state — 1,085 reported cases in 2022 (78.8 per 100,000), above the high-incidence-state median. Blacklegged (deer) ticks dominate wooded and edge habitat across Manchester, Nashua, and Concord, with the American dog tick common in open fields and the lone star tick now expanding into the state. Because ticks quest any day above 40°F, the risk window is far longer than most homeowners assume.

Key local data

About 60% of NH blacklegged ticks carry the Lyme bacterium; ticks quest any day above ~40°F without snow — NH DHHS. Frost (~Oct 19, Manchester) does NOT end tick season — NOAA.

We serve these communities

ManchesterNashuaConcordDerryBedfordSalemHudsonAmherst

Merrimack, Rockingham, and Hillsborough Counties

NH-licensed applicator · #782664
Same-day service
Family-owned since 2017

Service Area Map

Southern New Hampshire

When to act

Timing your treatment

The cheapest, most effective play is a spring/early-summer yard barrier plus year-round pet prevention — before nymph season hits full force.

The right window

Early June acaricide/leaf-litter barrier treatment to yard edges targets blacklegged nymphs (UNH Extension); a mid-May treatment also hits American dog ticks; an October treatment targets fall adults. Build a tick-safe zone in April: a 3-foot wood-chip or gravel border between lawn and woods, short grass, and woodpiles/feeders moved away from the house.

Heavy yard tick pressure — kids or pets picking up ticks in the yard

Property bordering woods, stone walls, or shaded perennial beds — prime tick habitat

Recurring ticks despite pet preventives and regular mowing

An attached tick found more than 24 hours after exposure — see a physician, don't wait

Fever or an expanding rash within 30 days of a bite — see a physician immediately

Tick Control

Free inspection and same-day tick service across southern New Hampshire. NH-licensed #782664.

Get a Free Inspection (603) 785-0118

Learn more about this pest

Common Questions

Frequently asked

Sources & references

UNH Extension — Biology and Management of Ticks in New Hampshire
activity windows, 40°F floor, nymph/adult peaks, June/May/Oct control timing
NH DHHS — Tickborne Diseases
40°F activity floor, April–Nov peak, 60% infection rate, NH tickborne diseases
CDC MMWR (Feb 15, 2024)
NH 1,085 Lyme cases in 2022; 78.8/100,000; high-incidence median 68.3
Tick Free NH — Identify
lone star tick confirmed in NH (2020), species identification
NH DHHS — Mosquito and Tick Transmitted Infections Announcement
tickborne infection surveillance context
NOAA/NWS Gray — Frost/Freeze Program
frost anchor context (frost does NOT end tick season)

Editorial disclaimer: This content is provided for informational purposes only and does not constitute pest control advice. Every property is unique — consult a licensed professional for guidance specific to your situation. Anchor Pest Services is licensed in New Hampshire (#782664).

Written & reviewed by

Verified

Daniel Brady

NH-Licensed Pesticide Applicator · License #782664 (NHDAMF, RSA 430)

Daniel Brady is the New Hampshire–licensed applicator behind Anchor Pest Services, a family-owned pest control company serving the Manchester area since 2017.

Verify license

Last updated Jul 2026

Anchor Pest Services

Whatever the season — we handle the timing for you.

Same-day service across Southern New Hampshire. NH-licensed #782664, family-owned since 2017. We track the local calendar so you don't have to guess the right window.

Get a Free Inspection (603) 785-0118

NH-licensed applicator
Same-day service
Pet & family-conscious

NH License #782664 · No obligation · We answer in person

Keep Exploring

When Are Ticks Most Active in NH? Tick & Lyme Timing

The short of it

When are they active — the whole year at a glance

A year in the life

Spring

Summer

Fall

Winter

Ticks in southern New Hampshire

Timing your treatment

Frequently asked

Sources & references

Whatever the season — we handle the timing for you.

Your next step

What Time of Year Are Ticks Most Active?

What Diseases Can Ticks Transmit to Dogs?

What Diseases Can Ticks Transmit to Cats?

Can Ticks Survive Winter in a Yard?

When Are Ticks Most Active in NH? Tick & Lyme Timing

The short of it

When are they active — the whole year at a glance

A year in the life

Spring

Summer

Fall

Winter

Ticks in southern New Hampshire

Timing your treatment

Frequently asked