Last updated: June 24, 2025
In September, the average temperature in Forest Park, United States hovers around 24°C (76°F), offering a pleasant climate. However, be prepared for temperature fluctuations; the mercury can dip to a cool 11°C (51°F) or climb to a sizzling 36°C (96°F). This month witnesses 109 mm (4.3 in) of precipitation spread over 8 days, contributing to an average humidity of 82%. Whether you're enjoying the warmth or bracing for a rain shower, Forest Park has a dynamic weather experience waiting for you!
In September in Forest Park, the average temperature is 24°C (76°F). The maximum can reach 36°C (96°F), and the minimum can be as low as 11°C (51°F). This makes it an ideal time for travelers seeking warm weather and a comfortable climate for outdoor activities.
In Forest Park in September, the total precipitation amount is 109 mm (4.3 in) spread over 8 days.
In Forest Park in September, humidity is 82%. With an average temperature of 24°C (76°F), this humidity feels like wearing a warm, damp blanket, making travel uncomfortable and sticky as you explore.
In Forest Park in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Forest Park.
UV Risk Categories
Weather in Forest Park varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Forest Park, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | 8°C (46°F) | 101 mm (4.0 inches) | 86% | moderate |
| February Weather | 11°C (52°F) | 133 mm (5.2 inches) | 84% | high |
| March Weather | 14°C (57°F) | 113 mm (4.5 inches) | 83% | very high |
| April Weather | 17°C (63°F) | 115 mm (4.5 inches) | 81% | extreme |
| May Weather | 22°C (72°F) | 93 mm (3.7 inches) | 81% | extreme |
| June Weather | 25°C (77°F) | 116 mm (4.6 inches) | 81% | extreme |
| July Weather | 27°C (80°F) | 103 mm (4.1 inches) | 83% | extreme |
| August Weather | 26°C (79°F) | 140 mm (5.5 inches) | 81% | very high |
| September Weather | 24°C (76°F) | 109 mm (4.3 inches) | 82% | very high |
| October Weather | 19°C (67°F) | 110 mm (4.3 inches) | 78% | very high |
| November Weather | 12°C (53°F) | 79 mm (3.1 inches) | 86% | high |
| December Weather | 9°C (49°F) | 133 mm (5.2 inches) | 89% | moderate |