Last updated: June 24, 2025
In September, the average temperature in Saint Clair, United States is a comfortable 18°C (65°F). However, temperatures can range from a cool 3°C (37°F) to a warm 33°C (92°F). Expect about 137 mm (5.4 in) of precipitation spread over 9 days, and with an average humidity of 75%, you might want to pack an umbrella along with your sunglasses!
In September in Saint Clair, the average temperature is 18°C (65°F), with maximums that can reach 33°C (92°F) and minimums that can drop to as low as 3°C (37°F). Overall, travelers should be prepared for a range of temperatures, ensuring they pack both warm clothing for the cooler evenings and lighter attire for the hotter days.
In Saint Clair in September, the total precipitation amount is 137 mm (5.4 in) over the course of 9 days.
In Saint Clair in September, humidity is 75%. With an average temperature of 18°C (65°F), this humidity feels like a warm, enveloping blanket that can make outdoor exploration feel a bit stifling, potentially leading to discomfort during travel activities.
In Saint Clair 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 Saint Clair.
UV Risk Categories
Weather in Saint Clair varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Saint Clair, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | -8°C (17°F) | 34 mm (1.3 inches) | 82% | moderate |
February Weather | -9°C (17°F) | 41 mm (1.6 inches) | 84% | moderate |
March Weather | 1°C (34°F) | 68 mm (2.7 inches) | 80% | moderate |
April Weather | 7°C (45°F) | 91 mm (3.6 inches) | 81% | very high |
May Weather | 15°C (60°F) | 140 mm (5.5 inches) | 74% | very high |
June Weather | 22°C (72°F) | 118 mm (4.7 inches) | 80% | very high |
July Weather | 23°C (74°F) | 103 mm (4.1 inches) | 80% | very high |
August Weather | 21°C (71°F) | 119 mm (4.7 inches) | 77% | very high |
September Weather | 18°C (65°F) | 137 mm (5.4 inches) | 75% | very high |
October Weather | 9°C (49°F) | 93 mm (3.7 inches) | 80% | moderate |
November Weather | 1°C (35°F) | 36 mm (1.4 inches) | 87% | moderate |
December Weather | -4°C (25°F) | 44 mm (1.7 inches) | 83% | moderate |