Average annual temperature is 12.3 °C
Absolute maximum temperature: 39.0 °C
Absolute minimum temperature: -16.1 °C
Number of sunny days: 201 days
Number of rainy days: 157 days
Number of snow days: 7 days
Look at detailed online map of Umatilla County
* Weather data for Umatilla County United States is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 13.3 | 13.4 | 15.1 | 26.5 | 31.9 | 33.0 | 37.2 | 39.0 | 33.0 | 26.1 | 20.3 | 17.9 |
| Average daytime temperature (°C) | 8.3 | 8.2 | 10.1 | 14.9 | 24.1 | 27.1 | 32.9 | 31.0 | 24.7 | 17.4 | 9.2 | 7.8 |
| Average temperature (°C) | 3.8 | 2.8 | 4.9 | 9.2 | 17.3 | 20.2 | 25.5 | 24.1 | 17.9 | 11.9 | 4.9 | 4.0 |
| Average night temperature (°C) | 0.6 | -1.1 | 1.2 | 4.6 | 11.2 | 13.9 | 17.9 | 17.9 | 12.5 | 7.4 | 1.7 | 1.4 |
| Absolute minimum temperature (°C) | -11.3 | -16.1 | -3.8 | -2.6 | 5.1 | 7.3 | 14.9 | 10.5 | 6.1 | -4.1 | -5.7 | -4.2 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 9.0 | 11.0 | 12.0 | 14.0 | 15.0 | 15.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 8.0 |
| Daylight mean duration (h) | 9.2 | 10.4 | 11.9 | 13.5 | 14.9 | 15.6 | 15.3 | 14.1 | 12.5 | 10.9 | 9.5 | 8.8 |
| Daylight minimum duration (h) | 8.0 | 9.0 | 11.0 | 12.0 | 14.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 8.0 | 8.0 |
| Sunshine mean duration (h) | 4.6 | 5.6 | 7.4 | 8.6 | 12.1 | 13.2 | 14.0 | 11.0 | 9.5 | 8.2 | 5.7 | 4.3 |
| Precipitation (mm) | 42 | 41 | 78 | 80 | 19 | 2 | 0 | 25 | 28 | 62 | 55 | 64 |
| Sunny days | 12 | 12 | 6 | 10 | 22 | 23 | 31 | 21 | 19 | 18 | 16 | 11 |
| Rainy days | 17 | 13 | 23 | 20 | 9 | 7 | 0 | 10 | 11 | 13 | 14 | 20 |
| Snow days | 2 | 3 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Umatilla County during the most sunny months:
Months with the longest average daylight duration in Umatilla County:
The largest precipitation sum in Umatilla County is at