Average annual temperature is 20.2 °C
Absolute maximum temperature: 37.9 °C
Absolute minimum temperature: -2.1 °C
Number of sunny days: 166 days
Number of rainy days: 199 days
Look at detailed online map of Fairfax
* Weather data for Fairfax 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) | 26.0 | 29.2 | 30.1 | 33.9 | 33.5 | 35.1 | 37.9 | 37.0 | 32.8 | 28.2 | 27.1 | 24.3 |
| Average daytime temperature (°C) | 19.8 | 23.3 | 25.0 | 27.0 | 28.7 | 31.6 | 34.6 | 33.9 | 29.9 | 24.8 | 20.1 | 17.0 |
| Average temperature (°C) | 13.1 | 16.7 | 17.9 | 20.0 | 22.4 | 25.4 | 28.1 | 28.1 | 24.2 | 19.1 | 14.8 | 12.0 |
| Average night temperature (°C) | 8.1 | 11.9 | 12.0 | 14.5 | 17.2 | 20.7 | 23.3 | 23.5 | 19.6 | 14.4 | 10.4 | 8.0 |
| Absolute minimum temperature (°C) | -2.1 | 1.2 | 0.8 | 8.5 | 11.0 | 16.7 | 20.9 | 21.4 | 15.4 | 7.3 | 0.1 | -0.7 |
| 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 | 13.0 | 12.0 | 11.0 | 10.0 | 10.0 |
| Daylight mean duration (h) | 10.4 | 11.1 | 12.0 | 12.9 | 13.7 | 14.1 | 14.0 | 13.3 | 12.4 | 11.4 | 10.6 | 10.2 |
| Daylight minimum duration (h) | 10.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 13.0 | 12.0 | 11.0 | 10.0 | 10.0 | 10.0 |
| Sunshine mean duration (h) | 7.5 | 8.4 | 9.0 | 9.6 | 10.4 | 10.4 | 11.5 | 10.9 | 10.0 | 9.0 | 6.8 | 6.6 |
| Precipitation (mm) | 91 | 92 | 64 | 114 | 90 | 171 | 80 | 148 | 84 | 37 | 49 | 159 |
| Sunny days | 17 | 16 | 18 | 9 | 11 | 6 | 6 | 5 | 15 | 23 | 18 | 22 |
| Rainy days | 14 | 12 | 13 | 21 | 20 | 24 | 25 | 26 | 15 | 8 | 12 | 9 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The largest precipitation sum in Fairfax is at