Average temperature in September is 18.5 °C
Average daytime temperature is 24.3 °C
Average night temperature is 13.9 °C
Absolute maximum temperature: 33.4 °C
Absolute minimum temperature: 8.5 °C
Number of sunny days: 13
Number of rainy days: 17
Number of snow days:
Precipitation sum: 45 mm
* Weather data for Washington 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 | 27 | 30.2 | 31.7 | 32.6 | 33.4 | 32.5 | 27.8 | 25.5 | 24.4 | 24.1 | 25.8 | 24.7 | 21.9 | 21.1 | 21.9 | 23.8 | 20.4 | 21.1 | 19.8 | 23.5 | 25.1 | 23 | 18 | 17.7 | 20.8 | 19.4 | 22.9 | 23 | 23.7 | 22.4 |
| Apparent max temperature | 27.9 | 31.6 | 32.8 | 34.7 | 35.9 | 33.3 | 30.4 | 28.2 | 26 | 25.5 | 26.7 | 25.9 | 22.1 | 19.5 | 21 | 23.8 | 20.8 | 20.1 | 18.6 | 23.7 | 25 | 21.4 | 15.4 | 17.8 | 21.9 | 18.6 | 22.8 | 22.9 | 25.1 | 22.5 |
| Mean temperature | 18.8 | 21.6 | 24.6 | 25.7 | 25.8 | 26 | 23.1 | 20.7 | 19.4 | 19.9 | 19.9 | 19.6 | 18.1 | 15.5 | 14.8 | 15.6 | 15.1 | 15.9 | 14.8 | 16.2 | 17.7 | 17.4 | 14.3 | 14.1 | 16.7 | 16.6 | 17.2 | 16.7 | 16.5 | 17.3 |
| Apparent mean temperature | 10.1 | 14.3 | 19.8 | 21.6 | 21.7 | 22 | 22.1 | 18.5 | 15.7 | 17.6 | 16.1 | 15.8 | 15.3 | 9.5 | 6.3 | 7.8 | 10.7 | 11.1 | 8.6 | 9 | 10.7 | 10.6 | 9.5 | 10.4 | 14.3 | 13.3 | 12.8 | 10.9 | 10.9 | 13.3 |
| Minimum temperature | 11.5 | 14.7 | 18.6 | 19.8 | 19.3 | 20 | 19.6 | 17 | 15.5 | 16.5 | 15.4 | 15.6 | 14.9 | 10.5 | 8.5 | 8.9 | 11.7 | 11.7 | 9.9 | 9.8 | 11.7 | 12.1 | 11.8 | 12.1 | 13.7 | 14.3 | 13.9 | 12.3 | 11.6 | 12.9 |
| Apparent min temperature | 18.2 | 21.8 | 25.8 | 27.7 | 28.1 | 27.8 | 25.5 | 22.8 | 20.7 | 21.5 | 21 | 20.6 | 18.5 | 14.5 | 13.1 | 15 | 15 | 15.4 | 13.8 | 15.4 | 17.2 | 16.1 | 12 | 13.1 | 17.5 | 16.1 | 16 | 16 | 16.6 | 17.8 |
| 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 | 13 | 13 | 12.9 | 12.9 | 12.8 | 12.8 | 12.7 | 12.7 | 12.7 | 12.6 | 12.6 | 12.5 | 12.5 | 12.4 | 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 | 12.1 | 12 | 11.6 | 11.9 | 11.8 | 8.1 | 7.8 | 4.8 | 7.3 | 9.8 | 8.6 | 11.6 | 11.5 | 11.5 | 11.5 | 6.2 | 10.8 | 9.2 | 11.4 | 11.3 | 11.2 | 4.2 | 1 | 0.8 | 5.3 | 10.7 | 6.7 | 10.7 | 8 |
| Precipitation (mm) | 0 | 0 | 0 | 0 | 0 | 0 | 6.7 | 0.8 | 2.3 | 10.2 | 0.4 | 4.6 | 1.7 | 0.2 | 0 | 0 | 8 | 1 | 0 | 0 | 0 | 0 | 0.9 | 5.1 | 1 | 0.4 | 0.3 | 0.3 | 0.8 | 0 |
| Precipitation hours | 0 | 0 | 0 | 0 | 0 | 0 | 10 | 6 | 12 | 13 | 3 | 5 | 7 | 1 | 0 | 0 | 10 | 3 | 0 | 0 | 0 | 0 | 6 | 19 | 7 | 1 | 3 | 1 | 6 | 0 |
| Wind speed (m/s) | 10.6 | 11.8 | 15.5 | 11.6 | 10.5 | 16 | 13.3 | 10.9 | 11.6 | 10.9 | 11.6 | 12.1 | 10.9 | 11.5 | 12.4 | 8.7 | 9.2 | 13.6 | 10.3 | 10.2 | 10.2 | 13.3 | 17.7 | 17.2 | 7.4 | 15.2 | 13.7 | 12.7 | 11.3 | 10.2 |
In September 2023, the highest daytime temperature in Washington was 33.4°C.
While the minimum temperature at night dropped to 8.5°C.
The average nighttime and daytime temperatures during September in Washington are 13.9°C and 24.3°C respectively.
The precipitation sum in September is about 45 mm.