Last updated: March 2, 2024
The weather in Lake Forest, United States, during September is characterized by an average temperature of 28°C (82°F). Highs can soar to 32°C (89°F), while lows may dip to 24°C (76°F). Typically, the humidity level in Lake Forest throughout September hovers around 76%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In September, Lake Forest averages 215 mm (8.5 inches) of rainfall, typically over the course of 24 rainy days. The month enjoys an average of 12 hours 15 minutes of daylight, with the sun shining for approximately 10 hours 25 minutes each day. Additionally, there is a 32% probability of sunny days during this period.
Precipitation
Rainy days
Sunshine hours
Chance of sun
In September, the UV Index in Lake Forest reaches a maximum of 11, indicating a level of Extreme exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 10 minutes.
| 07:00 | 08:00 | 09:00 | 10:00 | 11:00 | 12:00 | 13:00 | 14:00 | 15:00 | 16:00 | 17:00 | 18:00 | 19:00 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UVI | 1 | 1 | 2 | 5 | 7 | 10 | 11 | 11 | 9 | 6 | 3 | 1 | 1 |
| Exposure | Low | Moderate | High | VeryHigh | Extreme | VeryHigh | High | Moderate | Low | ||||
| Time to burn | 45 min | 30 min | 25 min | 15 min | 10 min | 15 min | 25 min | 30 min | 45 min | ||||