Climate averages 1991–2020
Spokane Valley weather
in September.
A warm, fairly dry month: the 3rd warmest and the 3rd driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Spokane Valley: daytime highs average 23.2°C and nights cool to about 10.5°C. By daytime temperature it is the 3rd warmest of the 12 months.
Expect about 22 mm of rain on roughly 4 days, which makes September a fairly dry month (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 38 min on an average September day.
The nearest other city in this atlas is Spokane (14 km away). In September its highs average 23.7°C, 0.5°C warmer than Spokane Valley, with 19 mm of rain.
Among the 498 cities listed in the United States, Spokane Valley ranks joint 393rd of 498 for the warmest September highs and joint 121st of 498 for the driest September (rainfall, lowest first). The mean September high of those 498 cities is 26.9°C; Spokane Valley is 3.7°C cooler than that mean.
From September to October, average highs fall by 8.5°C to 14.7°C, and monthly rainfall rises from 22 mm to 52 mm.
The annual picture
September 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
Spokane Valley climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.9°C-4.9°C | -4.9°C | 78 | 13.3 | 8.99 h |
| February | 4.6°C-4.0°C | -4.0°C | 54 | 10.7 | 10.210 h |
| March | 9.1°C-1.2°C | -1.2°C | 70 | 12.8 | 11.912 h |
| April | 13.7°C2.2°C | 2.2°C | 58 | 11.0 | 13.614 h |
| May | 19.2°C7.0°C | 7.0°C | 51 | 8.6 | 15.115 h |
| June | 23.0°C10.9°C | 10.9°C | 37 | 6.6 | 15.916 h |
| July | 29.0°C15.3°C | 15.3°C | 15 | 3.0 | 15.616 h |
| August | 28.7°C15.1°C | 15.1°C | 14 | 2.6 | 14.314 h |
| September, selected | 23.2°C10.5°C | 10.5°C | 22 | 4.4 | 12.613 h |
| October | 14.7°C4.5°C | 4.5°C | 52 | 8.5 | 10.911 h |
| November | 6.5°C-0.7°C | -0.7°C | 83 | 13.2 | 9.49 h |
| December | 1.7°C-4.3°C | -4.3°C | 85 | 12.8 | 8.59 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
September in nearby cities
- Spokane in SeptemberUnited States · 14 kmHigh 23.7°C · Low 11.0°C · 19 mm rain
- Kennewick in SeptemberUnited States · 217 kmHigh 27.4°C · Low 13.9°C · 6.9 mm rain
- Tri-Cities in SeptemberUnited States · 217 kmHigh 27.5°C · Low 14.0°C · 6.9 mm rain
- Missoula in SeptemberUnited States · 261 kmHigh 22.5°C · Low 9.8°C · 30 mm rain
- Yakima in SeptemberUnited States · 274 kmHigh 24.9°C · Low 10.7°C · 8.4 mm rain
- Kelowna in SeptemberCanada · 296 kmHigh 22.2°C · Low 12.7°C · 43 mm rain
- Bellevue in SeptemberUnited States · 372 kmHigh 20.7°C · Low 11.3°C · 67 mm rain
- Everett in SeptemberUnited States · 372 kmHigh 19.9°C · Low 11.2°C · 83 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 Spokane Valley) is explained once on the Spokane Valley year overview and on the Sources, method and limits page.