Climate averages 1991–2020
Spokane Valley weather
by month.
See how the year changes. July has the highest average daily maximum; August has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: JuneJulyAugustSeptember
Long-term climate patterns, not a forecast for a particular trip.
Across the year Spokane Valley averages a daytime high of 14.6°C and a nighttime low of 4.2°C, with about 619 mm of rain on roughly 107 days. July is the warmest month (average high 29.0°C) and December the coolest (1.7°C). December is the wettest month with 85 mm; August is the driest with 14 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): June, July, August and September. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in Spokane Valley
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 | 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
Nearby cities
- SpokaneUnited States · 14 kmHigh 15.1°C · Low 4.7°C · 551 mm rain a year
- KennewickUnited States · 217 kmHigh 19.2°C · Low 7.8°C · 228 mm rain a year
- Tri-CitiesUnited States · 217 kmHigh 19.4°C · Low 7.9°C · 228 mm rain a year
- MissoulaUnited States · 261 kmHigh 13.4°C · Low 3.1°C · 508 mm rain a year
- YakimaUnited States · 274 kmHigh 16.3°C · Low 4.7°C · 341 mm rain a year
- KelownaCanada · 296 kmHigh 14.0°C · Low 5.4°C · 622 mm rain a year
- BellevueUnited States · 372 kmHigh 14.8°C · Low 6.8°C · 1,316 mm rain a year
- EverettUnited States · 372 kmHigh 14.2°C · Low 6.8°C · 1,685 mm rain a year
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 limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC-8, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 47.70°, -117.20° (4 km from the city centre), adjusted up by 0.6°C for the difference between the city's elevation (610 m) and the cell's (698 m). Rain comes from the 0.25° cell at 47.75°, -117.25°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.