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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 82°F, while the coldest is December averaging around 17°F at night. Precipitation totals about 21 inches a year and is strongly seasonal — August alone averages 3.0 inches while June barely receives 0.30 inches. Snowfall is heavy (90 inches of snow per year on average).

☀️ Summers
Warm
Highs near 82°F in July.
About 3 days a year above 90 °F
❄️ Winters
Very cold
Lows near 17°F in December.
About 202 freezing nights a year
🌧️ Rain & snow
Fairly dry
About 21 in of rain a year, plus 90 in of snow.
Snow falls through the winter months
Sky & trend
Fairly sunny
More sun than cloud through the year.
+0.7 °F vs 50 years ago

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 figures TEMPERATURE °F 20°40°60°80° PRECIPITATION (in) 024 RainSnow JanAprJulOct

Clear vs cloudy days

Share of days each month that are clear, partly cloudy or cloudy · 1991–2020 · hover a month for the day counts 0%25%50%75%100% JanAprJulOct Cloudy Partly Cloudy Clear

Flagstaff climate normals (1991–2020)

JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)434652596879827974645243
Avg temp (°F)313338445161676558483830
Avg low (°F)182024283543515143322317
Precipitation (in)2.12.21.90.90.80.32.63.01.81.51.61.9
Snowfall (in)20.919.315.65.01.11.58.218.5
Jan – JunJanFebMarAprMayJun
Avg high (°F)434652596879
Avg temp (°F)313338445161
Avg low (°F)182024283543
Precipitation (in)2.12.21.90.90.80.3
Snowfall (in)20.919.315.65.01.1
Jul – DecJulAugSepOctNovDec
Avg high (°F)827974645243
Avg temp (°F)676558483830
Avg low (°F)515143322317
Precipitation (in)2.63.01.81.51.61.9
Snowfall (in)1.58.218.5

How often — frequency of weather events

JanFebMarAprMayJunJulAugSepOctNovDec
Days with measurable rain (days)78755212138547
Days with high ≥ 90°F (days)0.820.60.1
Days with low ≤ 32°F (days)302829241122182830
Days with snowfall ≥ 1 in (days)3320.90.30.213
Jan – JunJanFebMarAprMayJun
Days with measurable rain (days)787552
Days with high ≥ 90°F (days)0.8
Days with low ≤ 32°F (days)30282924112
Days with snowfall ≥ 1 in (days)3320.90.3
Jul – DecJulAugSepOctNovDec
Days with measurable rain (days)12138547
Days with high ≥ 90°F (days)20.60.1
Days with low ≤ 32°F (days)2182830
Days with snowfall ≥ 1 in (days)0.213

Sky & atmosphere

JanFebMarAprMayJunJulAugSepOctNovDec
Cloud cover (%)484946423830545234333647
Clear days (≤ 30% cloud)1110111215198816181511
Partly cloudy days (30–70%)11101212118121397911
Cloudy days (≥ 70%)99865411105659
Relative humidity (%)636153443828445247465262
Wind speed (mph)1.61.71.81.71.61.71.31.21.41.41.41.4
Jan – JunJanFebMarAprMayJun
Cloud cover (%)484946423830
Clear days (≤ 30% cloud)111011121519
Partly cloudy days (30–70%)11101212118
Cloudy days (≥ 70%)998654
Relative humidity (%)636153443828
Wind speed (mph)1.61.71.81.71.61.7
Jul – DecJulAugSepOctNovDec
Cloud cover (%)545234333647
Clear days (≤ 30% cloud)8816181511
Partly cloudy days (30–70%)121397911
Cloudy days (≥ 70%)11105659
Relative humidity (%)445247465262
Wind speed (mph)1.31.21.41.41.41.4
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.

How we build these numbers →