Average temperature in September is 23.4 °C
Average daytime temperature is 29.1 °C
Average night temperature is 18.6 °C
Absolute maximum temperature: 33.6 °C
Absolute minimum temperature: 14.4 °C
Number of sunny days: 16
Number of rainy days: 14
Number of snow days:
Precipitation sum: 47 mm
* Weather data for Allentown 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 | 27.7 | 26.8 | 29 | 30.7 | 30.3 | 33.6 | 32.3 | 30.9 | 30.4 | 29.5 | 31.5 | 32.2 | 31.7 | 30.8 | 27.8 | 29.3 | 27.1 | 27.7 | 27.1 | 27.5 | 26.5 | 27.2 | 29.5 | 30.1 | 31.7 | 27.3 | 25.8 | 24.7 | 28.4 | 28.7 |
| Apparent max temperature | 30.3 | 28.5 | 33.1 | 35.3 | 34.6 | 36.7 | 35.4 | 34.3 | 34.1 | 34.8 | 35.6 | 36.1 | 35.4 | 34.9 | 29.4 | 31 | 29.6 | 28.4 | 29.2 | 28 | 27.8 | 27 | 29.9 | 30.9 | 33.8 | 30.4 | 26.1 | 24.8 | 30.6 | 30 |
| Mean temperature | 25 | 23.2 | 23.2 | 24.1 | 24.2 | 25.9 | 26.5 | 24.1 | 24.2 | 24.1 | 25.9 | 26.2 | 25.2 | 24.9 | 23.3 | 23.2 | 23.2 | 22.1 | 21.6 | 22 | 22.1 | 22 | 21.5 | 22.3 | 23.1 | 22.5 | 21.6 | 20 | 20.9 | 22.5 |
| Apparent mean temperature | 25.3 | 19.8 | 19.1 | 18.3 | 20.2 | 22.3 | 24.6 | 21.8 | 22.3 | 23.9 | 23.4 | 23.1 | 23.6 | 23.8 | 22.9 | 20.8 | 22.7 | 16.6 | 14.6 | 17.2 | 19.4 | 18.5 | 15.6 | 13.7 | 17 | 19.2 | 19.5 | 15.6 | 15.9 | 18.1 |
| Minimum temperature | 22.7 | 19.6 | 17.7 | 17.4 | 18.7 | 20.3 | 22.6 | 19.1 | 19.4 | 20.4 | 20.5 | 20.3 | 20.8 | 20.8 | 20.3 | 19.5 | 20.2 | 16.7 | 14.6 | 16.7 | 18.6 | 18 | 15.4 | 14.4 | 16.9 | 18.5 | 18.7 | 16.2 | 15.9 | 17.1 |
| Apparent min temperature | 27.4 | 23.8 | 25.5 | 26.4 | 26.8 | 28.6 | 29.2 | 26.9 | 27.3 | 28 | 29.4 | 29.4 | 28.3 | 28.6 | 25.6 | 24.4 | 25.5 | 22.5 | 22.5 | 22.5 | 23 | 22.5 | 21.6 | 22.3 | 24.1 | 24 | 22.2 | 19.6 | 21.8 | 23.8 |
| 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) | 12.8 | 12.8 | 12.8 | 12.7 | 12.7 | 12.7 | 12.7 | 12.6 | 12.6 | 12.6 | 12.5 | 12.5 | 12.5 | 12.4 | 12.4 | 12.4 | 12.3 | 12.3 | 12.3 | 12.2 | 12.2 | 12.2 | 12.1 | 12.1 | 12.1 | 12 | 12 | 12 | 11.9 | 11.9 |
| Sunshine duration (h) | 11.2 | 11 | 11.7 | 11.9 | 10.5 | 11.6 | 10 | 11.3 | 11.4 | 10.2 | 11.3 | 11.3 | 9.2 | 9.8 | 10.3 | 11 | 5.6 | 11.2 | 11.1 | 9.5 | 10.2 | 11.1 | 11.1 | 11.1 | 11.1 | 3.4 | 3.4 | 10.8 | 11 | 10.9 |
| Precipitation (mm) | 0 | 0 | 0 | 0 | 0.1 | 0 | 11 | 0.6 | 1.3 | 1.2 | 0.6 | 0 | 0.5 | 3.9 | 1.7 | 0.3 | 22.6 | 0 | 0 | 0 | 0.6 | 0 | 0 | 0 | 0 | 2.8 | 0.2 | 0 | 0 | 0 |
| Precipitation hours | 0 | 0 | 0 | 0 | 1 | 0 | 3 | 2 | 4 | 5 | 2 | 0 | 4 | 5 | 6 | 2 | 15 | 0 | 0 | 0 | 4 | 0 | 0 | 0 | 0 | 6 | 2 | 0 | 0 | 0 |
| Wind speed (m/s) | 18.4 | 13.2 | 7.8 | 8.7 | 9.4 | 10.9 | 12.5 | 13 | 11 | 9.4 | 7.5 | 10.2 | 12 | 8.9 | 15.8 | 13.6 | 13.7 | 12.8 | 9.4 | 11.7 | 16.8 | 21.6 | 13.8 | 12 | 13 | 13.9 | 20.1 | 15.8 | 10.8 | 13.7 |
In September 2023, the highest daytime temperature in Allentown was 33.6°C.
While the minimum temperature at night dropped to 14.4°C.
The average nighttime and daytime temperatures during September in Allentown are 18.6°C and 29.1°C respectively.
The precipitation sum in September is about 47 mm.