Average annual temperature is 17.3 °C
Absolute maximum temperature: 37.3 °C
Absolute minimum temperature: -4.2 °C
Number of sunny days: 178 days
Number of rainy days: 187 days
Look at detailed online map of Fullerton
* Weather data for Fullerton 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) | 20.4 | 25.5 | 25.2 | 28.8 | 30.1 | 33.9 | 35.8 | 37.3 | 33.0 | 29.2 | 25.6 | 21.2 |
| Average daytime temperature (°C) | 14.0 | 17.4 | 18.6 | 21.7 | 25.9 | 29.9 | 32.9 | 32.5 | 29.5 | 23.4 | 17.8 | 13.6 |
| Average temperature (°C) | 9.0 | 11.6 | 12.5 | 15.8 | 20.0 | 23.6 | 26.7 | 26.3 | 23.3 | 17.6 | 11.9 | 8.3 |
| Average night temperature (°C) | 5.2 | 7.3 | 7.4 | 10.8 | 14.9 | 18.6 | 21.7 | 21.8 | 18.2 | 13.0 | 7.4 | 4.2 |
| Absolute minimum temperature (°C) | -3.5 | -3.3 | -4.2 | 5.4 | 5.8 | 14.6 | 18.7 | 17.9 | 13.8 | 6.1 | -2.7 | -2.6 |
| 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) | 10.2 | 11.0 | 12.0 | 13.0 | 13.9 | 14.4 | 14.2 | 13.4 | 12.4 | 11.3 | 10.4 | 9.9 |
| Daylight minimum duration (h) | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 13.0 | 12.0 | 11.0 | 10.0 | 10.0 | 9.0 |
| Sunshine mean duration (h) | 5.6 | 6.5 | 8.4 | 9.2 | 10.6 | 11.4 | 11.3 | 10.3 | 10.5 | 8.5 | 7.2 | 6.8 |
| Precipitation (mm) | 216 | 131 | 137 | 155 | 87 | 86 | 80 | 129 | 29 | 19 | 90 | 84 |
| Sunny days | 11 | 11 | 17 | 12 | 9 | 14 | 8 | 12 | 21 | 21 | 20 | 22 |
| Rainy days | 20 | 17 | 14 | 18 | 22 | 16 | 23 | 19 | 9 | 10 | 10 | 9 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Fullerton during the most sunny months:
The largest precipitation sum in Fullerton is at