Climate averages 1991–2020
Boise weather
in July.
A hot, very dry month: the warmest and the driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
July is a hot month in Boise: daytime highs average 32.7°C and nights cool to about 17.9°C. By daytime temperature it is the warmest month of the year.
Expect about 2.6 mm of rain on fewer than one day, which makes July a very dry month (the driest month of the year). Daylight, from sunrise to sunset, lasts about 15 h 05 min on an average July day.
The nearest other city in this atlas is Meridian (15 km away). In July its highs average 32.7°C, about as warm as Boise, with 3.4 mm of rain.
Among the 498 cities listed in the United States, Boise ranks joint 103rd of 498 for the warmest July highs and joint 78th of 498 for the driest July (rainfall, lowest first). The mean July high of those 498 cities is 30.3°C; Boise is 2.4°C warmer than that mean.
From July to August, average highs fall by 0.8°C to 31.9°C, and monthly rainfall rises from 2.6 mm to 3.3 mm.
The annual picture
July in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Boise climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 3.8°C-4.6°C | -4.6°C | 45 | 9.5 | 9.39 h |
| February | 6.8°C-2.5°C | -2.5°C | 31 | 7.7 | 10.510 h |
| March | 11.9°C0.9°C | 0.9°C | 36 | 8.9 | 11.912 h |
| April | 15.9°C3.8°C | 3.8°C | 31 | 7.2 | 13.413 h |
| May | 21.6°C8.5°C | 8.5°C | 31 | 5.9 | 14.715 h |
| June | 26.5°C13.0°C | 13.0°C | 16 | 3.2 | 15.415 h |
| July, selected | 32.7°C17.9°C | 17.9°C | 2.6 | 0.9 | 15.115 h |
| August | 31.9°C17.4°C | 17.4°C | 3.3 | 0.7 | 14.014 h |
| September | 26.2°C12.6°C | 12.6°C | 10 | 2.2 | 12.613 h |
| October | 17.7°C6.3°C | 6.3°C | 22 | 4.3 | 11.111 h |
| November | 9.3°C0.2°C | 0.2°C | 34 | 7.9 | 9.710 h |
| December | 3.7°C-4.1°C | -4.1°C | 50 | 10.1 | 9.09 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
July in nearby cities
- Meridian in JulyUnited States · 15 kmHigh 32.7°C · Low 18.1°C · 3.4 mm rain
- Nampa in JulyUnited States · 30 kmHigh 33.3°C · Low 19.2°C · 3.4 mm rain
- Kennewick in JulyUnited States · 370 kmHigh 34.1°C · Low 19.1°C · 3.8 mm rain
- Tri-Cities in JulyUnited States · 376 kmHigh 34.2°C · Low 19.2°C · 3.8 mm rain
- Missoula in JulyUnited States · 401 kmHigh 28.8°C · Low 15.3°C · 19 mm rain
- Bend in JulyUnited States · 413 kmHigh 27.7°C · Low 11.3°C · 14 mm rain
- Ogden in JulyUnited States · 437 kmHigh 31.4°C · Low 16.9°C · 9.3 mm rain
- Layton in JulyUnited States · 449 kmHigh 31.2°C · Low 16.9°C · 8.3 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Boise) is explained once on the Boise year overview and on the Sources, method and limits page.