Average annual temperature is 10.5 °C
Absolute maximum temperature: 36.8 °C
Absolute minimum temperature: -13.4 °C
Number of sunny days: 143 days
Number of rainy days: 220 days
Number of snow days: 2 days
Look at detailed online map of Cowlitz County
* Weather data for Cowlitz 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) | 12.9 | 14.1 | 16.8 | 29.0 | 30.9 | 28.5 | 32.3 | 36.8 | 29.1 | 27.5 | 15.1 | 15.4 |
| Average daytime temperature (°C) | 8.3 | 7.2 | 9.5 | 12.0 | 21.1 | 22.2 | 27.1 | 28.3 | 21.2 | 16.6 | 10.7 | 10.3 |
| Average temperature (°C) | 4.9 | 3.0 | 4.5 | 7.0 | 13.7 | 14.5 | 18.3 | 19.8 | 14.8 | 11.1 | 6.3 | 7.1 |
| Average night temperature (°C) | 2.5 | 0.1 | 1.4 | 3.9 | 8.6 | 9.0 | 11.7 | 13.8 | 10.5 | 7.6 | 3.4 | 4.6 |
| Absolute minimum temperature (°C) | -6.7 | -13.4 | -3.6 | -0.6 | 5.2 | 5.2 | 8.9 | 9.2 | 6.2 | -2.7 | -4.5 | -1.4 |
| 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) | 9.1 | 10.3 | 11.9 | 13.6 | 15.0 | 15.7 | 15.4 | 14.1 | 12.6 | 10.9 | 9.5 | 8.7 |
| 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) | 3.4 | 4.2 | 5.9 | 5.4 | 10.0 | 11.5 | 12.9 | 11.2 | 8.0 | 6.4 | 5.0 | 3.1 |
| Precipitation (mm) | 135 | 115 | 133 | 207 | 35 | 41 | 6 | 25 | 76 | 95 | 175 | 301 |
| Sunny days | 6 | 8 | 3 | 5 | 12 | 18 | 27 | 20 | 13 | 13 | 12 | 6 |
| Rainy days | 25 | 19 | 27 | 25 | 19 | 12 | 4 | 11 | 17 | 18 | 18 | 25 |
| Snow days | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Cowlitz County during the most sunny months:
Months with the longest average daylight duration in Cowlitz County:
The largest precipitation sum in Cowlitz County is at