Climate averages 1991–2020
Nampa weather
in August.
A hot, very dry month: the 2nd warmest and one of the driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Nampa: daytime highs average 32.3°C and nights cool to about 18.3°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 3.4 mm of rain on fewer than one day, which makes August a very dry month (one of the driest months of the year). Daylight, from sunrise to sunset, lasts about 13 h 59 min on an average August day.
The nearest other city in this atlas is Meridian (16 km away). In August its highs average 31.8°C, about as warm as Nampa, with 3.4 mm of rain.
Among the 498 cities listed in the United States, Nampa ranks joint 123rd of 498 for the warmest August highs and joint 96th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Nampa is 2.4°C warmer than that mean.
From August to September, average highs fall by 5.8°C to 26.5°C, and monthly rainfall rises from 3.4 mm to 9.8 mm.
The annual picture
August 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
Nampa climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 4.6°C-3.4°C | -3.4°C | 40 | 9.0 | 9.39 h |
| February | 7.7°C-1.9°C | -1.9°C | 26 | 7.4 | 10.510 h |
| March | 12.8°C1.5°C | 1.5°C | 31 | 8.6 | 11.912 h |
| April | 16.8°C4.7°C | 4.7°C | 28 | 6.4 | 13.413 h |
| May | 22.4°C9.8°C | 9.8°C | 29 | 5.9 | 14.715 h |
| June | 27.3°C14.2°C | 14.2°C | 16 | 3.4 | 15.415 h |
| July | 33.3°C19.2°C | 19.2°C | 3.4 | 1.0 | 15.115 h |
| August, selected | 32.3°C18.3°C | 18.3°C | 3.4 | 0.9 | 14.014 h |
| September | 26.5°C13.4°C | 13.4°C | 9.8 | 2.0 | 12.613 h |
| October | 18.2°C6.9°C | 6.9°C | 20 | 4.2 | 11.111 h |
| November | 9.9°C0.9°C | 0.9°C | 30 | 7.3 | 9.710 h |
| December | 4.4°C-2.9°C | -2.9°C | 42 | 9.3 | 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
August in nearby cities
- Meridian in AugustUnited States · 16 kmHigh 31.8°C · Low 17.4°C · 3.4 mm rain
- Boise in AugustUnited States · 30 kmHigh 31.9°C · Low 17.4°C · 3.3 mm rain
- Kennewick in AugustUnited States · 360 kmHigh 33.0°C · Low 18.5°C · 4.2 mm rain
- Tri-Cities in AugustUnited States · 365 kmHigh 33.2°C · Low 18.6°C · 4.2 mm rain
- Bend in AugustUnited States · 386 kmHigh 27.2°C · Low 11.3°C · 14 mm rain
- Missoula in AugustUnited States · 422 kmHigh 28.6°C · Low 14.9°C · 19 mm rain
- Ogden in AugustUnited States · 457 kmHigh 30.4°C · Low 16.4°C · 11 mm rain
- Yakima in AugustUnited States · 460 kmHigh 30.2°C · Low 15.1°C · 3.0 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 Nampa) is explained once on the Nampa year overview and on the Sources, method and limits page.
Meridian lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.