September weather forecastBloomington, IL
September
Weather in September
September embarks upon the transition from summer to fall in Bloomington, with temperatures starting to cool slightly. The city witnesses a gradual decrease in daylight hours, signaling the forthcoming change of season. Although rain showers become less frequent, they are substantial enough for the foliage to retain its lush green appearance. The cool winds that blow through the city provide an added freshness to the weather. By the end, September has given way to the first signs of fall, with temperatures and foliage starting to change.Temperature
The onset of September notes an average high-temperature of a still moderately hot 75.7°F (24.3°C), subtly shifted from August's 79.9°F (26.6°C). Bloomington, during September nights, observes an average temperature of 57.2°F (14°C).Humidity
In Bloomington, the average relative humidity in September is 77%.Rainfall
In Bloomington, in September, it is raining for 12.2 days, with typically 1.5" (38mm) of accumulated precipitation. Throughout the year, there are 140.6 rainfall days, and 22.44" (570mm) of precipitation is accumulated.Snowfall
In Bloomington, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:27 pm. On the last day of September, sunrise is at 6:52 am and sunset at 6:39 pm CDT.
Sunshine
In Bloomington, the average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index of 5 during September leads to these instructions:
Be vigilant - Preventing sunburn is recommended. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Bloomington, IL
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (30.7°F).
- Average low temperature in September: 57.2°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Bloomington, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Bloomington, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is January (11.1mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in September
Bloomington, IL
- Average humidity in September: 77%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Bloomington, IL
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is May (2.99").
The driest month (with the least rainfall) is January (1.18").
Average rainfall days in September
Bloomington, IL
- Average rainfall days in September: 12.2 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is February (5.3 days).
Average snowfall in September
Bloomington, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.44").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Bloomington, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.5 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Bloomington, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is June (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Bloomington, IL
- Average sunshine days in September: 15 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is July (9.7 days).
Average UV index in September
Bloomington, IL
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Bloomington, IL
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is September (Cloud cover 33).
Average visibility in September
Bloomington, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
