Last updated: June 24, 2025
In Sun Prairie, United States, the average temperature in September is a comfortable 15°C (59°F). However, be prepared for a temperature range where the minimum can drop to -2°C (28°F) and the maximum can soar to 35°C (95°F). During this time, expect about 38 mm (1.5 in) of precipitation over approximately 6 days, and enjoy an average humidity level of 68% to complete the experience.
In September in Sun Prairie, the average temperature is 15°C (59°F). The maximum can reach 35°C (95°F), while the minimum can drop to as low as -2°C (28°F). Travelers should be prepared for a wide range of temperatures and pack accordingly for a comfortable visit.
In Sun Prairie in September, the total precipitation amount is 38 mm (1.5 in) spread over 6 days.
In Sun Prairie in September, humidity is 68%. With an average temperature of 15°C (59°F), this humidity feels like a warm embrace, making it ideal for leisurely strolls and sightseeing, but travelers should be prepared for occasional discomfort as the mugginess can dampen outdoor activities.
In Sun Prairie in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Sun Prairie.
UV Risk Categories
Weather in Sun Prairie varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Sun Prairie, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -4°C (26°F) | 15 mm (0.6 inches) | 87% | low |
| February Weather | -7°C (19°F) | 39 mm (1.6 inches) | 88% | moderate |
| March Weather | 1°C (34°F) | 25 mm (1.0 inches) | 83% | moderate |
| April Weather | 5°C (42°F) | 59 mm (2.3 inches) | 78% | high |
| May Weather | 12°C (54°F) | 71 mm (2.8 inches) | 76% | very high |
| June Weather | 17°C (64°F) | 77 mm (3.0 inches) | 78% | very high |
| July Weather | 22°C (72°F) | 12 mm (0.5 inches) | 77% | very high |
| August Weather | 21°C (69°F) | 24 mm (0.9 inches) | 71% | very high |
| September Weather | 15°C (59°F) | 38 mm (1.5 inches) | 68% | high |
| October Weather | 7°C (44°F) | 37 mm (1.5 inches) | 72% | moderate |
| November Weather | 2°C (36°F) | 29 mm (1.2 inches) | 84% | moderate |
| December Weather | -2°C (29°F) | 26 mm (1.0 inches) | 90% | low |