Climate averages 1991–2020
Missoula weather
in August.
A hot, fairly dry month: the 2nd warmest and one of the driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Missoula: daytime highs average 28.6°C and nights cool to about 14.9°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 19 mm of rain on roughly 4 days, which makes August a fairly dry month (one of the driest months of the year). Daylight, from sunrise to sunset, lasts about 14 h 13 min on an average August day.
The nearest other city in this atlas is Spokane Valley (261 km away). In August its highs average 28.7°C, about as warm as Missoula, with 14 mm of rain.
Among the 498 cities listed in the United States, Missoula ranks joint 299th of 498 for the warmest August highs and 136th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Missoula is 1.3°C cooler than that mean.
From August to September, average highs fall by 6.2°C to 22.5°C, and monthly rainfall rises from 19 mm to 30 mm.
The annual picture
August in context
Monthly precipitation
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
Missoula climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 0.6°C-6.9°C | -6.9°C | 45 | 10.8 | 9.09 h |
| February | 2.7°C-5.7°C | -5.7°C | 41 | 9.9 | 10.310 h |
| March | 7.0°C-1.7°C | -1.7°C | 44 | 11.0 | 11.912 h |
| April | 11.4°C1.5°C | 1.5°C | 53 | 11.4 | 13.614 h |
| May | 17.9°C6.3°C | 6.3°C | 56 | 11.0 | 15.015 h |
| June | 22.2°C10.4°C | 10.4°C | 56 | 10.0 | 15.816 h |
| July | 28.8°C15.3°C | 15.3°C | 19 | 4.6 | 15.515 h |
| August, selected | 28.6°C14.9°C | 14.9°C | 19 | 3.8 | 14.214 h |
| September | 22.5°C9.8°C | 9.8°C | 30 | 5.8 | 12.613 h |
| October | 13.6°C3.5°C | 3.5°C | 44 | 8.6 | 10.911 h |
| November | 5.2°C-2.3°C | -2.3°C | 50 | 10.0 | 9.49 h |
| December | -0.1°C-7.4°C | -7.4°C | 51 | 10.4 | 8.69 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet 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
August in nearby cities
- Spokane Valley in AugustUnited States · 261 kmHigh 28.7°C · Low 15.1°C · 14 mm rain
- Spokane in AugustUnited States · 274 kmHigh 29.3°C · Low 15.7°C · 12 mm rain
- Lethbridge in AugustCanada · 326 kmHigh 25.2°C · Low 12.8°C · 35 mm rain
- Kennewick in AugustUnited States · 400 kmHigh 33.0°C · Low 18.5°C · 4.2 mm rain
- Boise in AugustUnited States · 401 kmHigh 31.9°C · Low 17.4°C · 3.3 mm rain
- Tri-Cities in AugustUnited States · 404 kmHigh 33.2°C · Low 18.6°C · 4.2 mm rain
- Meridian in AugustUnited States · 408 kmHigh 31.8°C · Low 17.4°C · 3.4 mm rain
- Nampa in AugustUnited States · 422 kmHigh 32.3°C · Low 18.3°C · 3.4 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 Missoula) is explained once on the Missoula year overview and on the Sources, method and limits page.