Average temperature in September is 17.6 °C
Average daytime temperature is 18.7 °C
Average night temperature is 16.7 °C
Absolute maximum temperature: 20.9 °C
Absolute minimum temperature: 13.1 °C
Number of sunny days: 12
Number of rainy days: 18
Number of snow days:
Precipitation sum: 68 mm
* Weather data for Castel Guernsey 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 | 17.4 | 17.7 | 20 | 20.9 | 20.5 | 20.1 | 19.7 | 19.3 | 20.8 | 20.3 | 18.3 | 17.8 | 17.8 | 17.2 | 19.6 | 19.4 | 18.9 | 17.9 | 17.9 | 19 | 16.6 | 15.7 | 18 | 19 | 18.2 | 17.9 | 19.3 | 19.4 | 17.9 | 18.3 |
| Apparent max temperature | 17.6 | 17.9 | 19.3 | 19.4 | 22.6 | 21 | 22.1 | 21.6 | 21.3 | 22.2 | 19.5 | 19 | 17.3 | 18 | 18.5 | 20.2 | 19.6 | 16.9 | 14.4 | 14.1 | 13.4 | 10.6 | 15.2 | 14.9 | 17.7 | 17.1 | 17.5 | 16.3 | 15.4 | 18.4 |
| Mean temperature | 16.8 | 17 | 18.4 | 20.1 | 19.2 | 18.7 | 18.7 | 18.4 | 19.3 | 18.6 | 17.6 | 17.7 | 16.7 | 16.5 | 18.3 | 18.5 | 18.1 | 17 | 17.4 | 17.7 | 15.2 | 14.8 | 16 | 17.7 | 17.3 | 17.5 | 17.7 | 17.7 | 16.3 | 16.9 |
| Apparent mean temperature | 14.4 | 16.1 | 15.9 | 17.5 | 18 | 18.8 | 18.5 | 18.2 | 18.2 | 16.1 | 17.1 | 14.4 | 13.4 | 15.6 | 16.1 | 16.5 | 14.4 | 10.5 | 10.8 | 11.6 | 9.8 | 9.4 | 10.5 | 13.1 | 15 | 14.4 | 12.1 | 12.8 | 11.4 | 13.6 |
| Minimum temperature | 16.5 | 16.6 | 17.1 | 19.2 | 18.4 | 17.8 | 18 | 17.9 | 18.1 | 16.7 | 16.7 | 17.1 | 16.1 | 16 | 17.2 | 18 | 17.2 | 16 | 16.5 | 16.2 | 13.5 | 13.1 | 15 | 16.9 | 16.9 | 16.9 | 17 | 16.6 | 15.6 | 15.9 |
| Apparent min temperature | 16.2 | 17.1 | 17.5 | 18.2 | 20.1 | 19.7 | 19.8 | 19.2 | 19.7 | 18.7 | 18.4 | 16.7 | 15.4 | 16.3 | 17.1 | 19 | 17.5 | 12.5 | 12.5 | 13.4 | 11.4 | 10 | 12.1 | 13.9 | 16.3 | 16.1 | 15 | 14.4 | 13.3 | 15.7 |
| 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) | 13.5 | 13.4 | 13.4 | 13.3 | 13.2 | 13.2 | 13.1 | 13.1 | 13 | 12.9 | 12.9 | 12.8 | 12.8 | 12.7 | 12.6 | 12.6 | 12.5 | 12.5 | 12.4 | 12.3 | 12.3 | 12.2 | 12.2 | 12.1 | 12 | 12 | 11.9 | 11.9 | 11.8 | 11.7 |
| Sunshine duration (h) | 11.7 | 12.2 | 12.1 | 12.1 | 12 | 11.8 | 11.6 | 10.6 | 11.9 | 10 | 8.9 | 11 | 11.7 | 11.7 | 11.6 | 2.4 | 7.3 | 10.3 | 3.3 | 3.5 | 10.5 | 11.2 | 7.2 | 10.6 | 10.5 | 10.2 | 2.4 | 5 | 10.2 | 10.3 |
| Precipitation (mm) | 4.7 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.8 | 2.2 | 0 | 0.3 | 0 | 0 | 5.5 | 11.5 | 6 | 1.2 | 14.9 | 4.3 | 3 | 0.3 | 0.7 | 0.5 | 9.2 | 1.9 | 0.5 | 0.1 | 0 |
| Precipitation hours | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | 3 | 0 | 2 | 0 | 0 | 7 | 10 | 11 | 12 | 11 | 12 | 9 | 2 | 3 | 1 | 11 | 5 | 3 | 1 | 0 |
| Wind speed (m/s) | 33.3 | 18.3 | 30.4 | 36.6 | 28.7 | 18.3 | 22.2 | 17.9 | 23 | 27.7 | 16.4 | 30.1 | 28.2 | 19.5 | 29.5 | 26.3 | 33.1 | 55.2 | 50.5 | 56.8 | 33.3 | 36.1 | 35.3 | 39.7 | 37.2 | 32.9 | 46.4 | 42.9 | 49.5 | 25.4 |
In September 2023, the highest daytime temperature in Castel was 20.9°C.
While the minimum temperature at night dropped to 13.1°C.
The average nighttime and daytime temperatures during September in Castel are 16.7°C and 18.7°C respectively.
The precipitation sum in September is about 68 mm.