Last updated: March 2, 2024
The weather in Riverside, United States, during September is characterized by an average temperature of 27°C (80°F). Highs can soar to 37°C (98°F), while lows may dip to 16°C (61°F). Typically, the humidity level in Riverside throughout September hovers around 69%.
Minimum temperature
Average temperature
Maximum temperature
Humidity
In September, Riverside averages 121 mm (4.8 inches) of rainfall, typically over the course of 11 rainy days. The month enjoys an average of 12 hours 18 minutes of daylight, with the sun shining for approximately 9 hours 12 minutes each day. Additionally, there is a 53% probability of sunny days during this period.
Precipitation
Rainy days
Sunshine hours
Chance of sun
In September, the UV Index in Riverside reaches a maximum of 10, indicating a level of VeryHigh exposure. The most intense UV radiation typically occurs between 13:00 and 15:00, during which unprotected skin may burn in as little as 15 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 | 4 | 7 | 9 | 10 | 9 | 8 | 5 | 3 | 1 | 1 |
| Exposure | Low | Moderate | High | VeryHigh | Moderate | Low | |||||||
| Time to burn | 45 min | 30 min | 25 min | 15 min | 30 min | 45 min | |||||||