Last updated: June 24, 2025
In Monticello, United States, the average temperature in September reaches a warm 25°C (78°F). However, be prepared for a range of temperatures, as it can drop to a chilly 11°C (53°F) or soar up to a scorching 38°C (100°F). Expect about 91 mm (3.6 in) of precipitation over 7 days, coupled with an average humidity level of 73%, making it an ideal time for outdoor adventures with the right preparations!
In September in Monticello, the average temperature is 25°C (78°F), with maximums reaching 38°C (100°F) and minimums dropping as low as 11°C (53°F). This varied climate makes it an ideal time for travelers to enjoy both warm and cooler activities, so pack accordingly!
In Monticello in September, the precipitation amount is 91 mm (3.6 in) over a span of 7 days.
In Monticello in September, humidity is 73%. With an average temperature of 25°C (78°F), this humidity feels like stepping into a warm, heavy blanket that wraps around you, making travel feel sluggish and requiring regular breaks to stay refreshed.
In Monticello 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 Monticello.
UV Risk Categories
Weather in Monticello varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Monticello, focusing on differences in temperature, rainfall, humidity, and UV levels.
Temperature | Precipitation | Humidity | UV | |
---|---|---|---|---|
January Weather | 7°C (46°F) | 115 mm (4.5 inches) | 84% | moderate |
February Weather | 9°C (49°F) | 183 mm (7.2 inches) | 83% | high |
March Weather | 15°C (59°F) | 179 mm (7.1 inches) | 80% | very high |
April Weather | 17°C (63°F) | 163 mm (6.4 inches) | 82% | very high |
May Weather | 23°C (73°F) | 147 mm (5.8 inches) | 83% | extreme |
June Weather | 26°C (80°F) | 118 mm (4.6 inches) | 80% | extreme |
July Weather | 28°C (83°F) | 97 mm (3.8 inches) | 80% | extreme |
August Weather | 27°C (82°F) | 111 mm (4.4 inches) | 75% | extreme |
September Weather | 25°C (78°F) | 91 mm (3.6 inches) | 73% | very high |
October Weather | 19°C (67°F) | 150 mm (5.9 inches) | 76% | high |
November Weather | 12°C (53°F) | 75 mm (3.0 inches) | 84% | high |
December Weather | 10°C (50°F) | 142 mm (5.6 inches) | 88% | moderate |