Flagstaff, Arizona climate: Normal weather by month, frost dates and records
Flagstaff's normal year runs from 17°F December nights to 82°F July afternoons, with 20.5 inches of precipitation and 90 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.2°C, December lows of −8°C, July highs of 28°C, 521 mm of precipitation a year.
- NOAA stationFlagstaff Airport
- Station IDUSW00003103
- Location35.14°N 111.67°W
- Elevation7,003 ft (2,135 m)
- Population77,539
On October 22, the normal high in Flagstaff is 61°F and the normal low 30°F, and the chance of measurable rain or snow is 16%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Flagstaff.
- Jan 43° 18°
- Feb 46° 20°
- Mar 52° 24°
- Apr 59° 28°
- May 68° 35°
- Jun 79° 43°
- Jul 82° 51°
- Aug 79° 51°
- Sep 74° 43°
- Oct 64° 32°
- Nov 52° 23°
- Dec 43° 17°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Flagstaff each month?
July is the warmest month, with normal highs of 82°F; December the coldest, with normal lows of 17°F. The most precipitation falls in August (3.04 in), the least in June (0.30 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 43°F | 18°F | 30.5°F | 2.05 | 20.9 | 7 | <1 | 31 | 10 h |
| February | 46°F | 20°F | 32.6°F | 2.17 | 19.3 | 8 | <1 | 27 | 10 h 50 min |
| March | 52°F | 24°F | 38.0°F | 1.88 | 15.6 | 7 | <1 | 29 | 11 h 50 min |
| April | 59°F | 28°F | 43.7°F | 0.89 | 5.0 | 5 | <1 | 24 | 13 h |
| May | 68°F | 35°F | 51.3°F | 0.77 | 1.1 | 5 | <1 | 12 | 14 h |
| June | 79°F | 43°F | 60.8°F | 0.30 | 0.0 | 2 | 1 | 2 | 14 h 30 min |
| July | 82°F | 51°F | 66.7°F | 2.61 | 0.0 | 12 | 2 | <1 | 14 h 20 min |
| August | 79°F | 51°F | 64.9°F | 3.04 | 0.0 | 13 | 1 | <1 | 13 h 30 min |
| September | 74°F | 43°F | 58.3°F | 1.84 | 0.0 | 8 | <1 | 2 | 12 h 30 min |
| October | 64°F | 32°F | 47.6°F | 1.52 | 1.5 | 5 | <1 | 18 | 11 h 20 min |
| November | 52°F | 23°F | 37.5°F | 1.55 | 8.2 | 4 | <1 | 28 | 10 h 20 min |
| December | 43°F | 17°F | 30.0°F | 1.90 | 18.5 | 7 | <1 | 30 | 9 h 50 min |
| Year (annual) | 62°F | 32°F | 46.8°F | 20.52 | 90.1 | 82 | 3 | 202 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 6°C | −8°C | −0.8°C | 52 mm | 53 cm |
| February | 8°C | −7°C | 0.3°C | 55 mm | 49 cm |
| March | 11°C | −5°C | 3.3°C | 48 mm | 40 cm |
| April | 15°C | −2°C | 6.5°C | 23 mm | 13 cm |
| May | 20°C | 1°C | 10.7°C | 20 mm | 3 cm |
| June | 26°C | 6°C | 16.0°C | 8 mm | 0 cm |
| July | 28°C | 11°C | 19.3°C | 66 mm | 0 cm |
| August | 26°C | 10°C | 18.3°C | 77 mm | 0 cm |
| September | 23°C | 6°C | 14.6°C | 47 mm | 0 cm |
| October | 18°C | 0°C | 8.7°C | 39 mm | 4 cm |
| November | 11°C | −5°C | 3.1°C | 39 mm | 21 cm |
| December | 6°C | −8°C | −1.1°C | 48 mm | 47 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00003103; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Flagstaff?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, June has the fewest days with rain (2).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00003103.
When is the last frost in Flagstaff?
In Flagstaff, the last spring frost (32°F) comes after June 4 in half of years and after June 19 in one year in ten; the first autumn frost comes before September 28 in half of years and before September 16 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- June 41 year in 10 after June 19; 9 in 10 after May 21
- First autumn frost, half of years before
- September 281 year in 10 before September 16; 9 in 10 before October 9
NOAA puts the median frost-free season at 115 days, and the season without a hard freeze (28°F) at 139 days.
A hard freeze (28°F) comes after May 20 in half of springs and before October 9 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Flagstaff in zone 6a in ZIP code 86005. By the map's own method, the average of each year's coldest night over 1991-2020, Flagstaff's NOAA station is in zone 6a: the coldest night of a typical year reaches −5°F (29 complete years).
Frost dates for every NOAA station in Arizona · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00003103; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Flagstaff?
In a normal year in Flagstaff, 3 days a year reach 90°F, 202 nights fall to 32°F or colder and 82 days bring measurable precipitation.
- Days at 90°F or more
- 3a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 202a normal year
- Days that stay below freezing
- 12high of 32°F or less
- Days with 0.01 inch of precipitation
- 82a normal year
- Days with 1 inch of snow or more
- 19a normal year
The highest temperature in Flagstaff's official record (kept by the National Weather Service since 1898) is 97°F, on July 5, 1973; the lowest is −30°F, on January 22, 1937.
The wettest calendar year on that record is 1965, with 36.59 in; the snowiest season is 1972–73, with 210.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00003103; records: ACIS (NOAA Regional Climate Centers), NWS threaded record FLGthr. Records use complete months only; a month missing more than three days is left out.
How sunny is Flagstaff?
Over a year 86% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Flagstaff, 5.6 kWh per square metre a day. June is the sunniest month (93%) and July the cloudiest (81%). Among the 459 U.S. places of 50,000 or more, that ranks tied 81st (with 7 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 83% | 3.2 |
| February | 84% | 4.2 |
| March | 87% | 5.7 |
| April | 88% | 7.0 |
| May | 89% | 7.8 |
| June | 93% | 8.4 |
| July | 81% | 6.9 |
| August | 82% | 6.4 |
| September | 89% | 5.9 |
| October | 89% | 4.8 |
| November | 89% | 3.6 |
| December | 81% | 2.8 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Flagstaff need?
A normal year in Flagstaff brings 6,746 heating degree days, 26% more than the median U.S. place (5,373), and 145 cooling degree days, 84% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,723 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,070 | 0 |
| February | 906 | 0 |
| March | 837 | 0 |
| April | 639 | 0 |
| May | 424 | 1 |
| June | 148 | 22 |
| July | 23 | 76 |
| August | 44 | 43 |
| September | 205 | 4 |
| October | 541 | 0 |
| November | 824 | 0 |
| December | 1,087 | 0 |
| Year (annual) | 6,746 | 145 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00003103. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Flagstaff been warmer than normal lately?
2025 averaged 49.1°F, 2.3°F above the 1991-2020 normal of 46.8°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 47.6°F | +0.8°F | 25.64 | 109.9 |
| 2022 | 47.4°F | +0.6°F | 18.50 | 56.3 |
| 2023 | 46.8°F | at normal | 24.66 | 143.8 |
| 2024 | 49.0°F | +2.3°F | 19.16 | 105.5 |
| 2025 | 49.1°F | +2.3°F | 20.31 | 65.7 |
Over 106 complete years from 1899 to 2025, the station's annual mean temperature rose at a fitted 3.4°F per century (+0.19°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00003103; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Flagstaff's climate compare?
Flagstaff is warmer than 3 of the other 96 places with their own NOAA record in Arizona, and wetter than 81. Across the 7,247 U.S. stations with normals, its annual mean of 46.8°F is warmer than 27%.
In the Köppen classification computed from these normals, Flagstaff is Dsb: continental, dry-summer, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Flagstaff share this climate record?
2 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Kachina Village, AZ3,212 people · 4 mi SW
- Mountainaire, AZ957 people · 4 mi S
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Flagstaff's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Flagstaff. This page uses Flagstaff Airport; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Flagstaff (4 mi SW) USC00023009 | 4 mi W | 7,125 ft | 44.7°F | 13°F | 82°F | 22.5 | 65 | June 23 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Flagstaff's climate
What is the coldest month in Flagstaff?
December, with a normal high of 43°F and a normal low of 17°F. The warmest is July (82°F by day, 51°F at night).
Does it snow in Flagstaff?
Yes: 90 inches in a normal year, falling on 28 days with 0.1 inch or more, the most in January (20.9 inches).
What is the rainiest month in Flagstaff?
August, with 3.04 in of precipitation in a normal year; the driest is June with 0.30 in.
What plant hardiness zone is Flagstaff in?
The USDA's 2023 map puts Flagstaff in zone 6a in ZIP code 86005. By the same method at Flagstaff's NOAA station, the coldest night of a typical year reaches −5°F (29 years, 1991-2020): zone 6a.
How late can frost come in Flagstaff?
In half of years the last 32°F night comes after June 4; in one year in ten it comes after June 19. Waiting until June 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Flagstaff in OctoberThis month day by day, its records and recent years
- Arizona climateThe statewide normals and every place in the state
- Walnut Canyon National Monument, AZ9 miles from this station, 50.6°F a year
- Fort Valley, AZ9 miles from this station, 47.4°F a year
- Bellemont, AZ11 miles from this station, 44.4°F a year
- Oak Creek Canyon, AZ14 miles from this station, 57.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made