Last updated: June 24, 2025
In September, the average temperature in Mount Morris, United States hovers around 18°C (65°F), with extremes ranging from a cool 1°C (34°F) to a warm 34°C (94°F). Expect about 87 mm (3.4 in) of precipitation over approximately 10 days, contributing to an average humidity of 80%. Whether you're planning to explore or relax, be prepared for a mix of comfortable warmth and refreshing rain!
In September in Mount Morris, the average temperature is 18°C (65°F), with maximums reaching up to 34°C (94°F) and minimums dipping as low as 1°C (34°F). Be prepared for a range of temperatures during your travels, bringing both lightweight clothing for the heat and warmer layers for the cooler moments.
In Mount Morris in September, the precipitation amount is 87 mm (3.4 in) over the course of 10 days.
In Mount Morris in September, humidity is 80%. With an average temperature of 18°C (65°F), this humidity feels like wandering through a warm, damp blanket, making every step slightly heavy and resulting in a constant sheen of sweat, which can be both refreshing and exhausting for travelers.
In Mount Morris 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 Mount Morris.
UV Risk Categories
Weather in Mount Morris varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Mount Morris, focusing on differences in temperature, rainfall, humidity, and UV levels.
| Temperature | Precipitation | Humidity | UV | |
|---|---|---|---|---|
| January Weather | -4°C (26°F) | 62 mm (2.4 inches) | 88% | low |
| February Weather | -3°C (27°F) | 65 mm (2.6 inches) | 87% | moderate |
| March Weather | 2°C (36°F) | 65 mm (2.6 inches) | 85% | moderate |
| April Weather | 8°C (46°F) | 92 mm (3.6 inches) | 86% | very high |
| May Weather | 15°C (59°F) | 104 mm (4.1 inches) | 80% | very high |
| June Weather | 21°C (70°F) | 104 mm (4.1 inches) | 80% | very high |
| July Weather | 23°C (74°F) | 76 mm (3.0 inches) | 80% | very high |
| August Weather | 22°C (72°F) | 80 mm (3.2 inches) | 80% | very high |
| September Weather | 18°C (65°F) | 87 mm (3.4 inches) | 80% | high |
| October Weather | 12°C (53°F) | 108 mm (4.3 inches) | 84% | moderate |
| November Weather | 3°C (38°F) | 65 mm (2.5 inches) | 89% | moderate |
| December Weather | 0°C (32°F) | 53 mm (2.1 inches) | 86% | low |