Tick Season: When Are Ticks Most Active?

Month-by-month tick activity calendar, peak danger months, and regional variation across the United States.

When Is Tick Season?

Tick season in the United States generally runs from April through September, with the highest risk in May, June, and July. However, the exact timing varies by region, species, and weather conditions.

In southern states, ticks can be active nearly year-round. In northern states, adult deer ticks remain active on mild winter days above 35°F. Climate change is also expanding tick season and range in many areas.

Month-by-Month Tick Activity

January

Low

Adult deer ticks active on mild days (above 35°F). Other species dormant.

February

Low

Minimal activity. Adult deer ticks may emerge during warm spells.

March

Rising

Activity increases as ground thaws. Lone star and dog ticks begin emerging in southern states.

April

Moderate

Tick season begins across most of the US. Nymph-stage deer ticks start emerging. Begin daily tick checks.

May

High

Peak nymph activity begins. Highest risk for Lyme disease transmission. All species active.

June

Peak

Peak tick season. Nymph deer ticks at maximum activity. Most tick-borne disease cases originate from June bites.

July

Peak

Continued peak activity. Lone star ticks very aggressive. Hot, dry spells may reduce activity slightly.

August

High

Nymph activity declining. Adult lone star and dog ticks still active. Heat may drive ticks to shaded areas.

September

Moderate

Adult deer ticks begin their fall feeding cycle. Continued risk through first hard frost.

October

Moderate

Adult deer ticks actively seeking hosts. Peak mating season for deer ticks. Don't let your guard down.

November

Low–Mod

Activity decreasing with cold weather. Adult deer ticks still active until sustained freeze.

December

Low

Most species dormant. Adult deer ticks can still be active on warm days above freezing.

Tick Season by Region

Northeast & Mid-Atlantic

CT, DE, MA, MD, ME, NH, NJ, NY, PA, RI, VT, VA

Season: April – November
Peak: May – July

Highest Lyme disease risk. Adult deer ticks active in fall/winter on mild days.

Upper Midwest

MN, WI, MI, IA, IL, IN, OH

Season: April – October
Peak: May – July

Significant Lyme disease risk. Deer ticks and dog ticks common.

Southeast

AL, AR, FL, GA, KY, LA, MS, NC, SC, TN

Season: Year-round (reduced Dec–Feb)
Peak: April – August

Lone star ticks dominant. Alpha-gal syndrome risk. Ticks active in mild winters.

South Central

TX, OK, MO, KS

Season: March – November
Peak: April – July

Lone star ticks and dog ticks common. Rocky Mountain spotted fever risk.

West

CA, OR, WA, CO, AZ, NM, UT, NV, MT, WY, ID

Season: March – October
Peak: April – June

Rocky Mountain wood tick in mountains. Western black-legged tick in coastal areas. Generally lower overall risk.

When Each Tick Species Is Most Active

Deer Tick
Nymphs: May–July
Adults: Oct–May (above 35°F)

Two active periods — nymphs in summer, adults in fall/winter

Lone Star Tick
Nymphs: May–Aug
Adults: April–August

Very aggressive. All life stages bite humans.

American Dog Tick
Nymphs: Rarely bite humans
Adults: April–August

Most common tick found on people in many states

Brown Dog Tick
Nymphs: Year-round indoors
Adults: Year-round

Only tick that can complete its lifecycle indoors

Gulf Coast Tick
Nymphs: Summer
Adults: March–September

Expanding northward. Found along Gulf Coast and Atlantic seaboard.

Tick PreventionTick Removal GuideTick Bite SymptomsLyme Disease GuideTick Species Guide

Get Tick Alerts for Your Area

Free weekly digest of tick activity near you. No spam, unsubscribe anytime.