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Your nature year

Flagstaff, Arizonathrough the year

When do frost, green-up and fall color come to Flagstaff?

Expect about 116 frost-free days in Flagstaff: the last spring frost usually comes around Jun 4, the first fall one around Sep 28, going by NOAA's Flagstaff Airport station 3.8 miles away. The USA-NPN spring index puts first leaf here around Apr 4 and first bloom around May 15.

Spring takes about 6 weeks to go from leaf to bloom. We follow 3 places within 150 miles of Flagstaff; the nearest lies 8 miles to the northwest. San Francisco Peaks, 8 miles from Flagstaff, is the nearest fall foliage spot on this site, usually at its best throughout the month of October. Mingus Mountain (44 mi) is the pick for wildflowers, July and August, after the summer rains (local timing). Across Arizona, fall color is usually well under way by late October.

Updated Sep 29. Sources: US Census Bureau, 2024 Gazetteer (places) ↗ (opens in a new tab), US Census Bureau, city and town population estimates, 2024 ↗ (opens in a new tab), NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal) ↗ (opens in a new tab)

Near Flagstaff right now

  • Fall color is usually well under way by late October in ArizonaStatewide · USA-NPN volunteer observations, 2020–2025 · not a forecast
    ~4 weeks
  • Last spring frost usually around Jun 4 · first fall frost around Sep 28NOAA 1991–2020 normals, Flagstaff Airport (3.8 mi, 50% dates)
    ~8 months
  • Grand Canyon South Rim · 66 mi · Local timing: Flowers from May through SeptemberWildflowers · in its window now
    In season
  • Fall foliage · San Francisco Peaks · 8 miusually throughout the month of October
    ~1 day

Best this weekend nearby

Oct 3–Oct 4 · within 150 straight-line miles of Flagstaff
  1. San Francisco Peaks · 8 mi · Fall foliage

    Usually throughout the month of October

    Sat Oct 3: Sunny, 70°F · Sun Oct 4: Sunny, 69°F

    No report yet

Places in their own usual window that weekend; reports are the latest official ones, forecasts from the National Weather Service.

Your guide around Flagstaff

Nearest places we cover
Map: approximate positions; state lines US Census.

Nearby, season by season

Real places within 150 miles, straight-line

Fall foliage

Wildflowers

Flagstaff's nature year

From the town's own dates and its nearest places
  • Spring green-upApr
  • Last spring frostJun
  • Wildflowers · Mingus MountainJul–Aug
  • First fall frostNowSep
  • Fall color (AZ)Oct

Flagstaff's year at a glance

  • Frost possible
  • Frost-free, ~Jun 4 to ~Sep 28
  • First leaf ~Apr 4
  • First bloom ~May 15
  • Fall color under way ~Oct 30 (AZ)
  • Today

Frost and green-up

Last spring frost

Jun 4

Average (50% date)

First fall frost

Sep 28

About 116 days without frost between

Spring green-up

Apr 4

First bloom around May 15

Frost: NOAA 1991–2020 climate normals at Flagstaff Airport (3.8 mi from Flagstaff), the day a 32 °F night is as likely as not. Green-up: the USA-NPN Spring Index, 1991–2020 average at the town.

Snow in Flagstaff

NOAA 1991–2020 daily normals

Snow usually becomes possible around Nov 23 (our calculation from NOAA's daily snow chances: the first day the chance of 0.1" or more of snow reaches 10%). NOAA's normals at Flagstaff Airport (3.8 mi away): 90 inches of snow in an average year, about 18.7 days with 1 inch or more.

0%15%30%10% lineOctDecFebApr

NOAA's chance of at least 0.1 inch of snow on each date (one value per week, September to May), averaged over 1991–2020. A typical year, not a forecast.

Questions people ask

When is the first frost in Flagstaff?

On average around Sep 28, and the last spring frost around Jun 4: about 116 days without frost between. These are NOAA's 1991–2020 normals at Flagstaff Airport, 3.8 miles away (the day a 32 °F night is as likely as not).

When does spring green-up reach Flagstaff?

The USA-NPN Spring Index puts first leaf around Apr 4 and first bloom around May 15, on average for 1991–2020 at the town.

Where can I see fall foliage near Flagstaff?

San Francisco Peaks, 8 miles (usually throughout the month of October). Distances are straight-line.

Where can I see wildflowers near Flagstaff?

Mingus Mountain, 44 miles (local timing: July and August, after the summer rains); Grand Canyon South Rim, 66 miles (local timing: Flowers from May through September). Distances are straight-line.

When does it start snowing in Flagstaff?

Snow usually becomes possible around Nov 23: our calculation from NOAA's daily snow chances: the first day the chance of 0.1" or more of snow reaches 10%, at Flagstaff Airport. An average year brings 90 inches (NOAA 1991–2020). A typical year, not a forecast.Sources: NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal snowfall) ↗ (opens in a new tab), NOAA NCEI U.S. Climate Normals 1991–2020 (daily snowfall probabilities) ↗ (opens in a new tab)

How we know

US Census Bureau, 2024 Gazetteer (places) (opens in a new tab) (Sep 27) · US Census Bureau, city and town population estimates, 2024 (opens in a new tab) (Sep 27) · NOAA NCEI U.S. Climate Normals 1991–2020 (annual/seasonal) (opens in a new tab) (Sep 27) · USA National Phenology Network, Spring Index 1991–2020 averages (opens in a new tab) (Sep 27) · USA National Phenology Network, colored leaves observations (opens in a new tab) (Sep 29)

All our sources and how we use them →