Last updated: June 24, 2025
In De Forest, United States, the average temperature in September is a pleasant 18°C (65°F). However, you may experience fluctuations, with temperatures dipping as low as 2°C (36°F) and peaking at 33°C (92°F). Expect around 110 mm (4.3 in) of precipitation over 9 days, and a comfortable average humidity of 79%.
In September, in De Forest, the average temperature is 18°C (65°F). The maximum can reach 33°C (92°F), while the minimum can be as low as 2°C (36°F). This temperature range makes De Forest an ideal destination for travelers seeking both warm days and cool nights.
In De Forest in September, the precipitation amount is 110 mm (4.3 in) over the course of 9 days.
In De Forest in September, humidity is 79%. With an average temperature of 18°C (65°F), this humidity feels like walking through a warm mist, making traveling slightly uncomfortable and sticky, but offering a refreshing escape when you find moments of shade or a breeze.
In De Forest 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 De Forest.
UV Risk Categories
Weather in De Forest varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in De Forest, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | -6°C (21°F) | 51 mm (2.0 inches) | 85% | moderate |
February Weather | -6°C (22°F) | 53 mm (2.1 inches) | 85% | moderate |
March Weather | 2°C (35°F) | 57 mm (2.3 inches) | 85% | moderate |
April Weather | 7°C (46°F) | 99 mm (3.9 inches) | 85% | very high |
May Weather | 15°C (59°F) | 130 mm (5.1 inches) | 78% | very high |
June Weather | 21°C (70°F) | 114 mm (4.5 inches) | 80% | very high |
July Weather | 24°C (75°F) | 99 mm (3.9 inches) | 78% | very high |
August Weather | 22°C (71°F) | 106 mm (4.2 inches) | 76% | very high |
September Weather | 18°C (65°F) | 110 mm (4.3 inches) | 79% | very high |
October Weather | 11°C (51°F) | 118 mm (4.6 inches) | 83% | moderate |
November Weather | 2°C (36°F) | 43 mm (1.7 inches) | 88% | moderate |
December Weather | -2°C (29°F) | 46 mm (1.8 inches) | 81% | low |