Flagstaff weather by month

The best time to visit Flagstaff is June, August and September — 94/100 in September, 24°C and 5 rainy days. The best season is summer, June to August (87/100 on average).

The worst month is January at 53/100 — cold, a little rain, clean air. See January →

Updated September 2026 · climate normals from ERA5 reanalysis

Planning the wider trip? Best time to visit United States →

Flagstaff🇺🇸 United States · Desert Southwest · City94
  1. 53Jan
  2. 60Feb
  3. 65Mar
  4. 78Apr
  5. 86May
  6. 91Jun
  7. 83Jul
  8. 88Aug
  9. 94Sep
  10. 81Oct
  11. 70Nov
  12. 61Dec

Best season: June to August (87/100 on average) · worst January (53/100)

Days
24°C
Nights
9°C
Wet days
5
Sun
11.1 h
Humidity
49%
Daylight
12 h
Flagstaff, United States
Photo: Dianna Sarmiento · Pexels

Flagstaff, month by month

Comfort score out of 100 for the kind of trip Flagstaff is best for, the average high, rainy days and hours of sun a day from the climate normals, and how busy it tends to be.

MonthScoreTierHighRainSunCrowdsOn
Jan53D6°C7 d8 hPeak2
Feb60C7°C4 d10 hBusy1
Mar65C10°C8 d10 hPeak1
Apr78B16°C2 d12 hBusy1
May86A20°C3 d13 hShoulder1
Jun91S27°C2 d13 hBusy2
Jul83A29°C10 d12 hPeak3
Aug88A27°C9 d12 hBusy1
Sep94S24°C5 d11 hPeak4
Oct81A18°C4 d10 hBusy3
Nov70B12°C4 d9 hPeak2
Dec61C8°C5 d8 hPeak3

What's on in Flagstaff through the year

Festivals, natural spectacles, holidays and the seasons to watch out for — curated and sourced. The month pages carry the detail.

May
  • Fire restrictions and smoke1 May – 10 Jul (usually)Hazard
June
  • Southwest monsoon15 Jun – 30 SepSeason
July
  • Fourth of July in the mountains3–5 JulHoliday
September
  • Flagstaff Festival of Science25 Sep – 4 OctFestival
  • Flagstaff Star Party1–3 OctFestival
  • Aspen colour on the Peaks20 Sep – 15 Oct (usually)Nature
November
  • Thanksgiving25–29 NovHoliday
  • Arizona Snowbowl season15 Nov – 10 Apr (usually)Opening
December
  • Christmas and New Year24 Dec – 1 JanHoliday

Everything on in Flagstaff through the year →

Crowds in Flagstaff in September

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Peak crowdsAspen colour on the Peaks, Summer break in United States(estimated)

JFMAMJJASOND

Peak crowdsBusyShoulder seasonQuiet

Traveller notes on Flagstaff

What people who have been say about the place — the year-round notes first, then month by month.

Forum posters cite an average March daytime high around 43F with nighttime lows in the teens, describing March as still genuinely winter in Flagstaff - posters are direct that snow at some point during the month is close to guaranteed, unless an unusually warm stretch arrives early. Posters describe a typical late-winter snowfall here as brief, usually gone within a day or two, with roads cleared quickly except during a major storm, which can shut down travel for several days at a time. Posters consistently recommend monitoring forecasts roughly a week ahead and building real flexibility into a March itinerary. Posters generally rate March as a high-precipitation, snow-capable month, workable for a visit but requiring genuine weather-contingency planning.
Tripadvisor community · March · 1 month ago · Read more on Tripadvisor ↗
Late September into early October is the window regulars name for this part of Arizona: temperatures cooling, patterns fairly stable and mostly sunny, crowds thinning. Flagstaff sits at about 7,000 feet, which is the whole point — days near 25°C while the desert below is still hot, and nights dropping to about 13, cold enough that a jacket or fleece is wanted early and late, with freezing possible in the second half of the month. The third week of September is when aspen, oak and birch begin turning on the Grand Canyon's North Rim. Layers you can shed is the standing advice.
Tripadvisor community · September · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Flagstaff's card on the map.