Flagstaff climate — normals and trends
Flagstaff (United States) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 8.4 °C and it receives 662 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (19.6 °C on average) and the coldest is January (-1.8 °C). Rainfall peaks in August.
Flagstaff averages 152 frost days, 7 hot days (≥ 30 °C) and 97 rainy days per year.
Flagstaff has warmed by +3.0 °C between 1940 and 2025, or +0.35 °C per decade. This trend is statistically significant.
The number of frost days there went from about 175 to 129 per year over the period.
The hottest day of the period reached 35.1 °C (on 10 July 2021) and the coldest -28.0 °C (on 23 December 1990).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
FlagstaffArizona
- coords
- 35.20°, -111.65°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
8.4°C
Average daily high
14.9°C
Average daily low
2.3°C
Annual rainfall
662mm
Sunshine / day
11.2h
Mean relative humidity
52%
Average peak wind
15.2km/h
Seasonal range
21.4°C
Frost days (< 0 °C)
152 d/yr
Hot days (≥ 30 °C)
7 d/yr
Rainy days (≥ 1 mm)
97 d/yr
Annual snowfall
140.4 cm
Average feels-like high
11.9 °C
Average feels-like low
-1.2 °C
Average peak gust
44.2 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
20.5 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+3.0 °C
since 1940
+0.4 °C per decade · r² = 0.65 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
35.1 °C
10 July 2021
Coldest day
-28.0 °C
23 December 1990
Wettest day
169 mm
11 August 1942
Windiest day
50.6 km/h
20 May 1975
Strongest gust
133.9 km/h
7 December 2009
Hottest feels-like
35.2 °C
9 July 2003
Coldest feels-like
-32.9 °C
12 January 1963
Snowiest day
46.2 cm
21 January 2010
Sunniest day
14.4 h
13 June 1941
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 4.7 °C | +0.5 °C | 8 mm | -38 mm |
| Feb | 10.8 °C | +5.1 °C | 23 mm | -23 mm |
| Mar | 9.4 °C | +0.9 °C | 73 mm | +17 mm |
| Apr | 14.2 °C | +1.0 °C | 34 mm | -3 mm |
| May | 19.8 °C | +1.1 °C | 41 mm | +10 mm |
| Jun | 26.5 °C | +1.6 °C | 49 mm | +30 mm |
| Jul | 27.6 °C | +1.3 °C | 46 mm | -74 mm |
| Aug | 28.3 °C | +3.8 °C | 41 mm | -94 mm |
| Sep | 22.5 °C | +0.5 °C | 54 mm | -2 mm |
| Oct | 17.8 °C | +1.5 °C | 70 mm | +29 mm |
| Nov | 12.9 °C | +3.3 °C | 48 mm | +15 mm |
| Dec | 10.7 °C | +5.6 °C | 18 mm | -23 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Flagstaff?
Flagstaff has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 8.4 °C and it receives 662 mm of precipitation per year.
What is the hottest day ever recorded in Flagstaff?
The hottest day measured in Flagstaff between 1940 and 2025 was 10 July 2021, reaching 35.1 °C.
What is the coldest day in Flagstaff?
The coldest day measured in Flagstaff between 1940 and 2025 was 23 December 1990, at -28.0 °C.
Does it snow in Flagstaff?
Yes. Flagstaff gets on average 140.4 cm of snow per year and has around 152 frost days.
Has the climate of Flagstaff warmed?
Yes: Flagstaff warmed by +3.0 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Flagstaff?
The wettest day measured in Flagstaff between 1940 and 2025 was 11 August 1942, with 169 mm of rain in 24 hours.
What was the windiest day in Flagstaff?
The windiest day measured in Flagstaff between 1940 and 2025 was 20 May 1975, with winds reaching 50.6 km/h.
What is the warmest month in Flagstaff?
The warmest month in Flagstaff is July (19.6 °C on average); the coldest is January (-1.8 °C).
How much does it rain in Flagstaff?
Flagstaff receives on average 662 mm of precipitation per year, spread over about 97 rainy days.
Is it sunny in Flagstaff?
Flagstaff gets on average 11.2 hours of sunshine per day, roughly 4,088 hours per year over 1940-2025.
What is the biggest single-day snowfall in Flagstaff?
The heaviest 24-hour snowfall measured in Flagstaff between 1940 and 2025 was 21 January 2010, with 46.2 cm.
Are there tropical nights in Flagstaff?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Flagstaff.
What was the most extreme apparent temperature in Flagstaff?
In Flagstaff, between 1940 and 2025, the highest apparent temperature reached 35.2 °C on 9 July 2003, and the lowest was -32.9 °C on 12 January 1963.
Compare Flagstaff with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Flagstaff