Are there ticks in New Hampshire?

Yes. New Hampshire has ticks in every county, led by the deer tick (blacklegged tick) that spreads Lyme disease, along with the American dog tick and the lone star tick. They are active whenever the ground is not frozen, and today 244 of the state's 244 towns are at moderate or high tick risk on TickZone's daily score.

What types of ticks live in New Hampshire?

New Hampshire has the deer tick (blacklegged tick), which carries Lyme disease; the American dog tick; and the lone star tick, which is established in the state and causes alpha-gal syndrome. See the New Hampshire tick identification chart for photos and how to tell them apart.

When does tick season start and end in New Hampshire?

In New Hampshire, ticks are active whenever the ground is not frozen, roughly March through November. Nymph deer ticks peak in June and July and cause most Lyme cases, and adult ticks have a second peak in the fall. On any winter day above freezing, adult ticks can still bite.

When is flea and tick season?

Flea and tick season generally runs from early spring through late fall, peaking in the warm summer months. In New Hampshire, start prevention for pets and people in March and keep it up through November, since ticks can bite on any mild day.

Which tick carries Lyme disease in New Hampshire?

The deer tick, also called the blacklegged tick, is the tick that spreads Lyme disease in New Hampshire. The American dog tick and lone star tick do not carry Lyme.

Ticks in New Hampshire

Ticks are active in New Hampshire whenever the ground is not frozen, led by the Lyme-carrying deer tick. TickZone scores all 244 New Hampshire towns every morning, so risk stays local: pick your town for today's number, a 7-day outlook, and what's driving it.

Tick season in New Hampshire

Tick season in New Hampshire runs whenever the ground is not frozen, roughly March through November, with two peaks. Nymph deer ticks, the poppy-seed-sized stage that causes most Lyme cases, peak from late May through July. Adult deer ticks make a second push in October and November, and on any winter day above about 40 F they can quest again. American dog ticks are busiest from April through July.

Generalized for the Northeast and Upper Midwest Lyme belt.
Life stage	J	F	M	A	M	J	J	A	S	O	N	D
Deer tick nymphs
Deer tick adults
American dog tick
Lone star tick

Peak Active

Generalized for the Northeast and Upper Midwest Lyme belt. Activity windows by life stage from TickEncounter (Univ. of Rhode Island) and the Northeast Regional Center for Excellence in Vector-Borne Diseases. Any warm spell can wake ticks earlier than the calendar suggests.

Those are averages, and any single week can run hotter or colder than the calendar suggests. The daily score on every town page folds the season, the weather, and local habitat into one number each morning, so it is the safer way to time yard work, hikes, and pet prevention.

Highest-risk towns in New Hampshire (2026)

New Hampshire's highest structural tick risk concentrates in Sullivan County, which holds 5 of the state's top 10 towns (187 CDC-reported Lyme cases per 100k). The top 10 towns run 92 to 96 percent forest, ranked at peak season so the list stays stable.

1Washington Sullivan CountyHigh at peak
2Springfield Sullivan CountyHigh at peak
3Goshen Sullivan CountyHigh at peak
4Grantham Sullivan CountyHigh at peak
5Lempster Sullivan CountyHigh at peak
6Newbury Merrimack CountyHigh at peak
7Hill Merrimack CountyHigh at peak
8Warner Merrimack CountyHigh at peak
9Bradford Merrimack CountyHigh at peak
10Wilmot Merrimack CountyHigh at peak

See the riskiest towns in every state →

All New Hampshire towns, by county

Belknap County · 11 towns · 84/100k Lyme

Carroll County · 19 towns · 75/100k Lyme

Cheshire County · 23 towns · 135/100k Lyme

Coos County · 29 towns · 30/100k Lyme

Grafton County · 39 towns · 130/100k Lyme

Hillsborough County · 31 towns · 86/100k Lyme

Merrimack County · 27 towns · 106/100k Lyme

Rockingham County · 37 towns · 73/100k Lyme

Strafford County · 13 towns · 109/100k Lyme

Sullivan County · 15 towns · 187/100k Lyme

New Hampshire tick questions

Are there ticks in New Hampshire?: Yes. New Hampshire has ticks in every county, led by the deer tick (blacklegged tick) that spreads Lyme disease, along with the American dog tick and the lone star tick. They are active whenever the ground is not frozen, and today 244 of the state's 244 towns are at moderate or high tick risk on TickZone's daily score.
What types of ticks live in New Hampshire?: New Hampshire has the deer tick (blacklegged tick), which carries Lyme disease; the American dog tick; and the lone star tick, which is established in the state and causes alpha-gal syndrome. See the New Hampshire tick identification chart for photos and how to tell them apart.
When does tick season start and end in New Hampshire?: In New Hampshire, ticks are active whenever the ground is not frozen, roughly March through November. Nymph deer ticks peak in June and July and cause most Lyme cases, and adult ticks have a second peak in the fall. On any winter day above freezing, adult ticks can still bite.
When is flea and tick season?: Flea and tick season generally runs from early spring through late fall, peaking in the warm summer months. In New Hampshire, start prevention for pets and people in March and keep it up through November, since ticks can bite on any mild day.
Which tick carries Lyme disease in New Hampshire?: The deer tick, also called the blacklegged tick, is the tick that spreads Lyme disease in New Hampshire. The American dog tick and lone star tick do not carry Lyme.