Average annual temperature is 13.3 °C
Absolute maximum temperature: 32.7 °C
Absolute minimum temperature: 2.5 °C
Number of sunny days: 252 days
Number of rainy days: 113 days
Look at detailed online map of Ross Valley
* Weather data for Ross Valley 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) | 18.1 | 17.2 | 17.6 | 23.4 | 25.1 | 24.4 | 32.7 | 31.7 | 26.7 | 31.9 | 23.5 | 18.4 |
| Average daytime temperature (°C) | 13.7 | 13.0 | 12.4 | 16.4 | 17.5 | 18.6 | 24.5 | 24.4 | 21.0 | 22.5 | 17.6 | 15.0 |
| Average temperature (°C) | 10.0 | 8.6 | 9.0 | 11.4 | 13.0 | 14.2 | 17.2 | 17.8 | 16.2 | 16.6 | 13.2 | 11.4 |
| Average night temperature (°C) | 7.5 | 5.5 | 6.5 | 7.8 | 10.1 | 11.2 | 12.2 | 13.9 | 13.1 | 12.6 | 9.9 | 8.9 |
| Absolute minimum temperature (°C) | 2.5 | 3.2 | 2.7 | 4.5 | 7.1 | 9.2 | 10.3 | 12.2 | 10.6 | 7.0 | 6.3 | 5.2 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 14.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.9 | 10.8 | 12.0 | 13.2 | 14.2 | 14.7 | 14.5 | 13.6 | 12.4 | 11.2 | 10.1 | 9.6 |
| Daylight minimum duration (h) | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 | 9.0 |
| Sunshine mean duration (h) | 6.0 | 7.7 | 7.9 | 11.3 | 11.8 | 12.6 | 12.7 | 11.3 | 10.6 | 9.1 | 7.8 | 5.6 |
| Precipitation (mm) | 384 | 82 | 321 | 16 | 44 | 6 | 0 | 1 | 6 | 18 | 82 | 210 |
| Sunny days | 12 | 15 | 8 | 26 | 23 | 28 | 31 | 28 | 23 | 23 | 19 | 16 |
| Rainy days | 19 | 13 | 23 | 4 | 8 | 2 | 0 | 3 | 7 | 8 | 11 | 15 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Ross Valley during the most sunny months:
The largest precipitation sum in Ross Valley is at