FleaDatesTick season › Arizona

Mountain West · AZ

When are ticks active in Arizona?

Arizona ticks don't take a real winter break: average temperatures stay above the ~40°F questing threshold in every month, with pressure heaviest Mar–Nov.

Tick season year-round Heaviest Mar–Nov
January — Moderate February — Moderate March — High April — High May — Peak June — Peak July — Peak August — Peak September — Peak October — Peak November — High December — Moderate J F M A M J J A S O N D AZ ticks Heaviest Mar–Nov

Ticks to know in Arizona

Species brown dog tickSpecies Rocky Mountain wood tickSpecies American dog tick

Arizona's tick picture is unusual: the brown dog tick can finish its entire life cycle inside a house, kennel or garage, and in parts of the state it transmits Rocky Mountain spotted fever, so an indoor infestation here is treated as a health matter and not just a nuisance. Rocky Mountain wood ticks belong to the higher country around Flagstaff, appearing with spring warmth, and statewide pressure stays strong from March into November. Make the after-walk check a habit — ears, toes, groin, collar line — even when the outing was only around the neighborhood.

Wherever the calendar sits this month, the habit that actually catches ticks is the after-walk check: ears, collar line, armpits, between the toes. Prevention plus checks beats either alone.

Month-by-month tick activity in Arizona
MonthTypical activityAverage temperature
January Moderate 47°F
February Moderate 49.6°F
March High 55.4°F
April High 61.7°F
May Peak 70°F
June Peak 79.4°F
July Peak 83.5°F
August Peak 82.1°F
September Peak 76.8°F
October Peak 65.9°F
November High 54.7°F
December Moderate 46.3°F

Estimates from NOAA U.S. Climate Normals (1991–2020), averaged across 3 weather stations near Arizona's larger cities, using the ~40°F activity threshold reported in published tick research. Real years run early or late with the weather.

Fleas peak later. Arizona flea season typically runs early February to early December — see the Arizona flea season page.

Frequently asked questions

When does tick season start in Arizona?

It never fully stops. Arizona's average temperatures sit above the ~40°F questing threshold all year, so tick checks and prevention are a twelve-month routine, with extra vigilance Mar–Nov.

What ticks live in Arizona?

The species dog owners most often meet in Arizona: brown dog tick, Rocky Mountain wood tick, American dog tick. Arizona's tick picture is unusual: the brown dog tick can finish its entire life cycle inside a house, kennel or garage, and in parts of the state it transmits Rocky Mountain spotted fever, so an indoor infestation here is treated as a health matter and not just a nuisance. Rocky Mountain wood ticks belong to the higher country around Flagstaff, appearing with spring warmth, and statewide pressure stays strong from March into November. Make the after-walk check a habit — ears, toes, groin, collar line — even when the outing was only around the neighborhood.

Do I need tick prevention in winter in Arizona?

Yes. Ticks overwinter under leaf litter and snow rather than dying off, and mild spells wake them — which is why veterinary organizations recommend year-round parasite prevention. The calendar shows when pressure peaks, not when protection can lapse.

What about fleas in Arizona?

Fleas run on a warmer calendar — in Arizona that's early February to early December. See the Arizona flea season page for that month-by-month picture.

Nearby states