Climate averages 1991–2020
Tri-Cities weather
in August.
A hot, very dry month: the 2nd warmest and the 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Tri-Cities: daytime highs average 33.2°C and nights cool to about 18.6°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 4.2 mm of rain on roughly 1 day, which makes August a very dry month (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 10 min on an average August day.
The nearest other city in this atlas is Kennewick (6 km away). In August its highs average 33.0°C, about as warm as Tri-Cities, with 4.2 mm of rain.
Among the 498 cities listed in the United States, Tri-Cities ranks joint 87th of 498 for the warmest August highs and joint 98th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Tri-Cities is 3.3°C warmer than that mean.
From August to September, average highs fall by 5.6°C to 27.5°C, and monthly rainfall rises from 4.2 mm to 6.9 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
Tri-Cities climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 6.0°C-1.5°C | -1.5°C | 34 | 8.1 | 9.19 h |
| February | 9.3°C-0.3°C | -0.3°C | 23 | 6.2 | 10.310 h |
| March | 14.3°C2.8°C | 2.8°C | 24 | 5.9 | 11.912 h |
| April | 19.3°C6.6°C | 6.6°C | 17 | 4.9 | 13.514 h |
| May | 25.0°C11.5°C | 11.5°C | 18 | 4.5 | 15.015 h |
| June | 28.9°C15.3°C | 15.3°C | 13 | 2.8 | 15.716 h |
| July | 34.2°C19.2°C | 19.2°C | 3.8 | 1.0 | 15.415 h |
| August, selected | 33.2°C18.6°C | 18.6°C | 4.2 | 1.0 | 14.214 h |
| September | 27.5°C14.0°C | 14.0°C | 6.9 | 1.8 | 12.613 h |
| October | 18.9°C7.9°C | 7.9°C | 22 | 5.0 | 11.011 h |
| November | 10.7°C2.3°C | 2.3°C | 29 | 7.3 | 9.59 h |
| December | 5.6°C-1.2°C | -1.2°C | 35 | 8.4 | 8.79 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
- Kennewick in AugustUnited States · 6 kmHigh 33.0°C · Low 18.5°C · 4.2 mm rain
- Yakima in AugustUnited States · 108 kmHigh 30.2°C · Low 15.1°C · 3.0 mm rain
- Spokane in AugustUnited States · 207 kmHigh 29.3°C · Low 15.7°C · 12 mm rain
- Spokane Valley in AugustUnited States · 217 kmHigh 28.7°C · Low 15.1°C · 14 mm rain
- Auburn in AugustUnited States · 259 kmHigh 24.1°C · Low 13.9°C · 28 mm rain
- Kent in AugustUnited States · 263 kmHigh 24.6°C · Low 14.4°C · 33 mm rain
- Gresham in AugustUnited States · 264 kmHigh 26.1°C · Low 13.9°C · 20 mm rain
- Federal Way in AugustUnited States · 266 kmHigh 23.7°C · Low 13.6°C · 28 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 Tri-Cities) is explained once on the Tri-Cities year overview and on the Sources, method and limits page.
Kennewick lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.