Average temperature in September is 17.4 °C
Average daytime temperature is 24.4 °C
Average night temperature is 12.4 °C
Absolute maximum temperature: 33.2 °C
Absolute minimum temperature: 7.8 °C
Number of sunny days: 16
Number of rainy days: 14
Number of snow days:
Precipitation sum: 71 mm
* Weather data for Lake Oswego 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 | 26.8 | 29.7 | 24.3 | 22.1 | 22.4 | 25.7 | 24.4 | 25.3 | 29.8 | 29.5 | 27.5 | 26.3 | 26.5 | 32.6 | 33.2 | 32.8 | 29.8 | 23.3 | 22.3 | 21.4 | 23.4 | 25 | 23.8 | 16.7 | 17.7 | 18.2 | 17.5 | 17.7 | 16.2 | 19 |
| Apparent max temperature | 25.5 | 30.8 | 25.4 | 21.3 | 21.8 | 25.6 | 24.2 | 24.9 | 29.4 | 29.4 | 26.9 | 26 | 25.5 | 31.7 | 32.3 | 30.7 | 28.5 | 21.9 | 20.3 | 19.6 | 21.3 | 23.8 | 21.3 | 17.9 | 17.3 | 16.4 | 15.4 | 16.4 | 15.7 | 16.6 |
| Mean temperature | 18.5 | 21.5 | 19.2 | 17.8 | 16.4 | 16.9 | 18 | 17.4 | 19.5 | 20.7 | 19.4 | 19.5 | 19.3 | 20.3 | 23 | 22 | 18.2 | 17.9 | 15.6 | 16 | 14.9 | 16 | 16.8 | 14.3 | 14.8 | 14.5 | 13.9 | 13.5 | 13.4 | 13.1 |
| Apparent mean temperature | 16.1 | 16 | 14.8 | 13.1 | 10.3 | 11.1 | 12.1 | 10.9 | 11.4 | 13.1 | 13.8 | 13.2 | 15.1 | 12.4 | 11.8 | 13.7 | 11 | 15.1 | 8.8 | 11.5 | 7 | 6.2 | 11.2 | 11.5 | 13.1 | 9.8 | 9.2 | 9.7 | 10.8 | 6.7 |
| Minimum temperature | 15.4 | 15.6 | 15.1 | 13.1 | 10.9 | 11.6 | 12.5 | 11.3 | 11.6 | 13.4 | 14.2 | 13.5 | 14.5 | 12.5 | 13.6 | 13.8 | 11.7 | 14.7 | 10.2 | 12.1 | 8.8 | 7.8 | 13.4 | 11.8 | 13.7 | 11.9 | 11.8 | 10.7 | 11.8 | 8.3 |
| Apparent min temperature | 19 | 21.9 | 19.2 | 17.3 | 15.8 | 16.5 | 17.7 | 16.9 | 19 | 20.5 | 18.9 | 19.3 | 19.4 | 19.5 | 21.7 | 21.7 | 16.9 | 17 | 13.6 | 14.6 | 13.1 | 14.5 | 14.8 | 14.6 | 14.4 | 12.7 | 11.8 | 12.4 | 12.5 | 11.4 |
| 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) | 13.3 | 13.2 | 13.2 | 13.1 | 13.1 | 13 | 13 | 12.9 | 12.9 | 12.8 | 12.8 | 12.7 | 12.7 | 12.6 | 12.6 | 12.5 | 12.5 | 12.4 | 12.4 | 12.3 | 12.3 | 12.2 | 12.1 | 12.1 | 12 | 12 | 11.9 | 11.9 | 11.8 | 11.8 |
| Sunshine duration (h) | 8.5 | 11.4 | 10.1 | 7.1 | 10.2 | 11.9 | 8 | 11.8 | 11.8 | 11.8 | 5.8 | 11.8 | 8.1 | 11.7 | 11.6 | 11.6 | 9.7 | 5.7 | 11.4 | 10.7 | 10.3 | 11.3 | 4.5 | 0 | 0 | 8 | 9.5 | 8.5 | 2.6 | 8.3 |
| Precipitation (mm) | 4.8 | 0 | 8.4 | 1.5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.4 | 0 | 0 | 0 | 0 | 0.1 | 0 | 1.1 | 0 | 0 | 1.8 | 8.3 | 13 | 11.1 | 14.8 | 2.5 | 1.7 | 1.8 |
| Precipitation hours | 10 | 0 | 3 | 8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 1 | 0 | 4 | 0 | 0 | 4 | 13 | 21 | 18 | 18 | 13 | 10 | 7 |
| Wind speed (m/s) | 18.7 | 14.5 | 20.4 | 13.4 | 9.4 | 7.8 | 14.7 | 12.8 | 8.8 | 8.9 | 12.3 | 10.8 | 15.2 | 14.4 | 14.4 | 12.3 | 12.3 | 12.3 | 16.3 | 15.8 | 14.8 | 10.1 | 15 | 8.3 | 22.2 | 27 | 24.1 | 13 | 11.6 | 17.2 |
In September 2023, the highest daytime temperature in Lake Oswego was 33.2°C.
While the minimum temperature at night dropped to 7.8°C.
The average nighttime and daytime temperatures during September in Lake Oswego are 12.4°C and 24.4°C respectively.
The precipitation sum in September is about 71 mm.