Summer temperatures · Arizona
How hot does Flagstaff get in summer?
In a typical summer, June to August, Flagstaff averages highs around 80°F and lows around 48°F.
About 3 days a year reach 90°F or hotter, and 100°F doesn’t show up in a typical year. About 61 days a year get to 80°F or warmer. That makes it the 6th coolest summer of the 129 US cities we track.
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The hottest high in the forecast for the next 48 hours is about 55°F.
Flagstaff averages summer highs around 80°F and lows around 48°F, so it is the part of Arizona that never got the memo about summer.
Live 48-hour forecast from OpenWeatherMap, refreshed about every half hour. Alerts from the National Weather Service.
Summer at a glance
| Average summer high | 80°F |
|---|---|
| Average summer low | 48°F |
| Days a year at 80°F or warmer | 61 |
| Days a year at 90°F or hotter | 3 |
| Days a year at 100°F or hotter | none |
| Average winter high, for comparison | 44°F |
Summer here is June to August. Counts are averages a year.
Cities with about the same summer
- San Francisco, California: highs around 73°F, lows around 55°F
- Duluth, Minnesota: highs around 75°F, lows around 54°F
- Great Falls, Montana: highs around 80°F, lows around 49°F
More about the weather here
Source: NOAA U.S. Climate Normals, 1991 to 2020, station USW00003103.