Last updated: June 24, 2025
The average temperature in Bonner-West Riverside, United States during September is a comfortable 13°C (56°F). Be prepared for a wide temperature range, with minimums dipping to -3°C (26°F) and maximums soaring to 32°C (91°F). Expect 37 mm (1.5 in) of precipitation spread over 7 days, alongside an average humidity of 67%.
In September in Bonner-West Riverside, the average temperature is 13°C (56°F), with maximums reaching up to 32°C (91°F) and minimums dropping as low as -3°C (26°F). This wide temperature range makes it essential to pack both warm and cool clothing for your travels.
In Bonner-West Riverside in September, the precipitation amount is 37 mm (1.5 in) during a span of 7 days.
In Bonner-West Riverside in September humidity is 67%. With an average temperature of 13°C (56°F), this humidity feels like a damp chill that seeps into your bones, making outdoor activities a bit uncomfortable, but still manageable for travelers who embrace the cool, crisp air.
In Bonner-West Riverside in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Bonner-West Riverside.
UV Risk Categories
Weather in Bonner-West Riverside varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Bonner-West Riverside, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -5°C (24°F) | 48 mm (1.9 inches) | 93% | low |
| February Weather | -6°C (21°F) | 98 mm (3.8 inches) | 92% | moderate |
| March Weather | 0°C (32°F) | 59 mm (2.3 inches) | 89% | high |
| April Weather | 4°C (39°F) | 84 mm (3.3 inches) | 85% | high |
| May Weather | 10°C (50°F) | 88 mm (3.5 inches) | 80% | very high |
| June Weather | 15°C (59°F) | 74 mm (2.9 inches) | 78% | very high |
| July Weather | 20°C (68°F) | 19 mm (0.8 inches) | 77% | very high |
| August Weather | 19°C (67°F) | 27 mm (1.1 inches) | 66% | very high |
| September Weather | 13°C (56°F) | 37 mm (1.5 inches) | 67% | very high |
| October Weather | 5°C (41°F) | 70 mm (2.8 inches) | 77% | moderate |
| November Weather | 0°C (33°F) | 71 mm (2.8 inches) | 89% | moderate |
| December Weather | -3°C (27°F) | 70 mm (2.7 inches) | 95% | low |