Summer temperatures · Idaho
How hot does Boise get in summer?
In a typical summer, June to August, Boise averages highs around 88°F and lows around 59°F.
About 55 days a year reach 90°F or hotter, and about 9 reach 100°F. About 103 days a year get to 80°F or warmer. That makes it the 60th 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 62°F.
Boise reaches 90°F on about 55 days a year, but the nights fall to about 59°F, and floating the river through town is basically a civic duty.
Live 48-hour forecast from OpenWeatherMap, refreshed about every half hour. Alerts from the National Weather Service.
Summer at a glance
| Average summer high | 88°F |
|---|---|
| Average summer low | 59°F |
| Days a year at 80°F or warmer | 103 |
| Days a year at 90°F or hotter | 55 |
| Days a year at 100°F or hotter | 9 |
| Average winter high, for comparison | 41°F |
Summer here is June to August. Counts are averages a year.
Cities with about the same summer
- Asheville, North Carolina: highs around 84°F, lows around 63°F
- Toledo, Ohio: highs around 85°F, lows around 63°F
- Quad Cities, Illinois and Iowa: highs around 85°F, lows around 63°F
More about the weather here
Source: NOAA U.S. Climate Normals, 1991 to 2020, station USW00024131.