September weather forecastManhattan, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Manhattan, Illinois, with an average temperature fluctuating between 74.3°F (23.5°C) and 57°F (13.9°C).Temperature
Manhattan records a mild change in average high-temperature during September, easing from 80.2°F (26.8°C) in August to a still moderately hot 74.3°F (23.5°C). Manhattan's temperature drops to an average low of 57°F (13.9°C) during the nights of September.Humidity
In Manhattan, the average relative humidity in September is 77%.Rainfall
In September, the rain falls for 13.2 days. Throughout September, 2.52" (64mm) of precipitation is accumulated. In Manhattan, during the entire year, the rain falls for 149.8 days and collects up to 31.26" (794mm) of precipitation.Snowfall
May through September are months without snowfall in Manhattan.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September, sunrise is at 6:18 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:34 pm CDT.
Sunshine
In Manhattan, the average sunshine in September is 8.3h.UV index
In September, the average daily maximum UV index in Manhattan is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: During September, 4 as the daily maximum UV index converts into the following advice:
Take necessary precautions - Suggestions to elude sunburn are provided. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Manhattan, IL
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in September: 57°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (17.4°F).
Average pressure in September
Manhattan, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Manhattan, IL
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is January (9.7mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in September
Manhattan, IL
- Average humidity in September: 77%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Manhattan, IL
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is May (4.21").
The driest months (with the least rainfall) are February and December (1.61").
Average rainfall days in September
Manhattan, IL
- Average rainfall days in September: 13.2 days
The months with the highest number of rainy days are June and July (17.3 days).
The month with the least rainy days is February (5.3 days).
Average snowfall in September
Manhattan, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Manhattan, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.3 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
Manhattan, IL
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 18min
The month with the most sunshine is August (Average sunshine: 9h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Manhattan, IL
- Average sunshine days in September: 15 days
The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is April (10.7 days).
Average UV index in September
Manhattan, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Manhattan, IL
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Manhattan, IL
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, February, July and August (5mi).
