Average temperature in September is 21.6 °C
Average daytime temperature is 28.1 °C
Average night temperature is 16.1 °C
Absolute maximum temperature: 35.6 °C
Absolute minimum temperature: 9.1 °C
Number of sunny days: 21
Number of rainy days: 9
Number of snow days:
Precipitation sum: 40 mm
* Weather data for Fullerton United States is based on climate observations for 2023 year
| September (°C) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperature | 33.3 | 35.6 | 35.3 | 34.9 | 33 | 25.9 | 28.1 | 28.9 | 29.8 | 27.4 | 22.5 | 23.9 | 24.5 | 25 | 24.1 | 25.1 | 23.9 | 31.8 | 32 | 29.6 | 27.5 | 23.9 | 25.6 | 24.5 | 25.3 | 23 | 23.2 | 30.4 | 32.5 | 32.5 |
| Apparent max temperature | 32.9 | 35.9 | 35.1 | 34.1 | 30.9 | 24.9 | 26.7 | 29.5 | 31.3 | 26.2 | 21.2 | 23 | 22.1 | 23.2 | 23.4 | 23.8 | 23.9 | 29.6 | 32.5 | 29.7 | 28.1 | 25 | 25.4 | 22.1 | 23.8 | 22.4 | 22.9 | 29.1 | 31.2 | 30.8 |
| Mean temperature | 26.4 | 28.5 | 29.8 | 28.6 | 26.4 | 18.8 | 20 | 21.7 | 22.6 | 20.5 | 17.2 | 17.4 | 18.4 | 20.4 | 19 | 18.8 | 16.7 | 21.3 | 25 | 21.8 | 22.5 | 20.5 | 20.6 | 18.1 | 18.5 | 17.7 | 16.5 | 20.1 | 27.2 | 26 |
| Apparent mean temperature | 20.1 | 22.1 | 21.9 | 21.4 | 18.7 | 10.2 | 11.4 | 14.5 | 16.6 | 15.4 | 11.9 | 8.6 | 10.3 | 14.8 | 17.1 | 13.7 | 7.5 | 12.3 | 19.2 | 12.6 | 17 | 16.8 | 18.4 | 9.8 | 11.5 | 11.5 | 10.1 | 12.9 | 21 | 22 |
| Minimum temperature | 21.1 | 23.2 | 24.3 | 22.2 | 21 | 12.8 | 13 | 14.3 | 16.6 | 16.3 | 12.9 | 10.4 | 12.2 | 16.1 | 16.9 | 14.1 | 9.1 | 15.2 | 18.6 | 12.8 | 17.8 | 16.9 | 17.7 | 12.4 | 12.9 | 12 | 10.8 | 14.1 | 22.9 | 21.7 |
| Apparent min temperature | 25.4 | 27.9 | 28.1 | 27.5 | 24.5 | 16.1 | 18.6 | 21.2 | 22.5 | 20.4 | 16.4 | 15.9 | 16.2 | 18.8 | 19.1 | 18.3 | 15.4 | 19 | 24.2 | 21.7 | 21.7 | 20 | 21.2 | 15.7 | 17.5 | 16.8 | 16 | 19 | 25.4 | 25.8 |
| September | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight duration (h) | 13.1 | 13.1 | 13 | 13 | 13 | 12.9 | 12.9 | 12.8 | 12.8 | 12.7 | 12.7 | 12.6 | 12.6 | 12.5 | 12.5 | 12.5 | 12.4 | 12.4 | 12.3 | 12.3 | 12.2 | 12.2 | 12.1 | 12.1 | 12 | 12 | 12 | 11.9 | 11.9 | 11.8 |
| Sunshine duration (h) | 12.2 | 12.2 | 12.2 | 12.1 | 12.1 | 11.5 | 12 | 11.9 | 10.6 | 3.8 | 10.2 | 11.6 | 11.5 | 10.1 | 3.3 | 10.7 | 11.3 | 11.2 | 11 | 11.1 | 10.2 | 5 | 7.7 | 10.2 | 11 | 11 | 10.9 | 10.9 | 9.9 | 10.8 |
| Precipitation (mm) | 0 | 0 | 0 | 0 | 0 | 0 | 2.2 | 0 | 0 | 13.5 | 0.6 | 0 | 0 | 0 | 11 | 0.2 | 0 | 0 | 0 | 0 | 0.8 | 0.4 | 7.6 | 0 | 0 | 0 | 0 | 0 | 0 | 3.2 |
| Precipitation hours | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 6 | 2 | 0 | 0 | 0 | 10 | 1 | 0 | 0 | 0 | 0 | 4 | 3 | 7 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| Wind speed (m/s) | 26.5 | 22.3 | 23 | 30.3 | 34.6 | 37.7 | 15.1 | 22 | 10.6 | 18.1 | 15.6 | 9 | 19.6 | 22 | 13 | 14.4 | 10.5 | 26.6 | 19.9 | 14.7 | 28 | 24.5 | 23.3 | 24.4 | 17.3 | 15.9 | 13.2 | 23.2 | 23.1 | 26.7 |
In September 2023, the highest daytime temperature in Fullerton was 35.6°C.
While the minimum temperature at night dropped to 9.1°C.
The average nighttime and daytime temperatures during September in Fullerton are 16.1°C and 28.1°C respectively.
The precipitation sum in September is about 40 mm.