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Flagstaff, Arizona climate
Csb Warm-summer Mediterranean
Flagstaff has a seasonal cool-temperate climate (Warm-summer Mediterranean, Köppen Csb). The hottest month is July with an average daily high near 28°C, while the coldest is December averaging around −8°C at night. Precipitation totals about 521 mm a year and is strongly seasonal — August alone averages 77 mm while June barely receives 8 mm. Snowfall is heavy (229 cm of snow per year on average).
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation split into rain and snow · 1991–2020 normals · hover a month for the exact figuresClear vs cloudy days
Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day countsFlagstaff climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 6 | 8 | 11 | 15 | 20 | 26 | 28 | 26 | 23 | 18 | 11 | 6 |
| Avg temp (°C) | −1 | 0 | 3 | 7 | 11 | 16 | 19 | 18 | 15 | 9 | 3 | −1 |
| Avg low (°C) | −8 | −7 | −5 | −2 | 1 | 6 | 11 | 10 | 6 | 0 | −5 | −8 |
| Precipitation (mm) | 52 | 55 | 48 | 23 | 20 | 8 | 66 | 77 | 47 | 39 | 39 | 48 |
| Snowfall (cm) | 53 | 49 | 40 | 13 | 3 | — | — | — | — | 4 | 21 | 47 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | 6 | 8 | 11 | 15 | 20 | 26 |
| Avg temp (°C) | −1 | 0 | 3 | 7 | 11 | 16 |
| Avg low (°C) | −8 | −7 | −5 | −2 | 1 | 6 |
| Precipitation (mm) | 52 | 55 | 48 | 23 | 20 | 8 |
| Snowfall (cm) | 53 | 49 | 40 | 13 | 3 | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 28 | 26 | 23 | 18 | 11 | 6 |
| Avg temp (°C) | 19 | 18 | 15 | 9 | 3 | −1 |
| Avg low (°C) | 11 | 10 | 6 | 0 | −5 | −8 |
| Precipitation (mm) | 66 | 77 | 47 | 39 | 39 | 48 |
| Snowfall (cm) | — | — | — | 4 | 21 | 47 |
How often — frequency of weather events
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 7 | 8 | 7 | 5 | 5 | 2 | 12 | 13 | 8 | 5 | 4 | 7 |
| Days with high ≥ 32°C (days) | — | — | — | — | — | 0.8 | 2 | 0.6 | 0.1 | — | — | — |
| Days with low ≤ 0°C (days) | 30 | 28 | 29 | 24 | 11 | 2 | — | — | 2 | 18 | 28 | 30 |
| Days with snowfall ≥ 2.5 cm (days) | 3 | 3 | 2 | 0.9 | 0.3 | — | — | — | — | 0.2 | 1 | 3 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 7 | 8 | 7 | 5 | 5 | 2 |
| Days with high ≥ 32°C (days) | — | — | — | — | — | 0.8 |
| Days with low ≤ 0°C (days) | 30 | 28 | 29 | 24 | 11 | 2 |
| Days with snowfall ≥ 2.5 cm (days) | 3 | 3 | 2 | 0.9 | 0.3 | — |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Days with measurable rain (days) | 12 | 13 | 8 | 5 | 4 | 7 |
| Days with high ≥ 32°C (days) | 2 | 0.6 | 0.1 | — | — | — |
| Days with low ≤ 0°C (days) | — | — | 2 | 18 | 28 | 30 |
| Days with snowfall ≥ 2.5 cm (days) | — | — | — | 0.2 | 1 | 3 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 48 | 49 | 46 | 42 | 38 | 30 | 54 | 52 | 34 | 33 | 36 | 47 |
| Clear days (≤ 30% cloud) | 11 | 10 | 11 | 12 | 15 | 19 | 8 | 8 | 16 | 18 | 15 | 11 |
| Partly cloudy days (30–70%) | 11 | 10 | 12 | 12 | 11 | 8 | 12 | 13 | 9 | 7 | 9 | 11 |
| Cloudy days (≥ 70%) | 9 | 9 | 8 | 6 | 5 | 4 | 11 | 10 | 5 | 6 | 5 | 9 |
| Relative humidity (%) | 63 | 61 | 53 | 44 | 38 | 28 | 44 | 52 | 47 | 46 | 52 | 62 |
| Wind speed (m/s) | 0.7 | 0.8 | 0.8 | 0.8 | 0.7 | 0.7 | 0.6 | 0.5 | 0.6 | 0.6 | 0.6 | 0.6 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 48 | 49 | 46 | 42 | 38 | 30 |
| Clear days (≤ 30% cloud) | 11 | 10 | 11 | 12 | 15 | 19 |
| Partly cloudy days (30–70%) | 11 | 10 | 12 | 12 | 11 | 8 |
| Cloudy days (≥ 70%) | 9 | 9 | 8 | 6 | 5 | 4 |
| Relative humidity (%) | 63 | 61 | 53 | 44 | 38 | 28 |
| Wind speed (m/s) | 0.7 | 0.8 | 0.8 | 0.8 | 0.7 | 0.7 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 54 | 52 | 34 | 33 | 36 | 47 |
| Clear days (≤ 30% cloud) | 8 | 8 | 16 | 18 | 15 | 11 |
| Partly cloudy days (30–70%) | 12 | 13 | 9 | 7 | 9 | 11 |
| Cloudy days (≥ 70%) | 11 | 10 | 5 | 6 | 5 | 9 |
| Relative humidity (%) | 44 | 52 | 47 | 46 | 52 | 62 |
| Wind speed (m/s) | 0.6 | 0.5 | 0.6 | 0.6 | 0.6 | 0.6 |
Methodology & sources
Temperature & precipitation — the official 1991–2020 climate normals from NOAA's U.S. Climate Normals, measured at Flagstaff AP (NOAA GHCN station USW00003103), about 6 km from the city centre.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.