September weather forecastNorthfield, IL
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Northfield, Illinois, with an average temperature varying between 60.3°F (15.7°C) and 71.6°F (22°C).Temperature
September's arrival comes with a mild decrease in the average high-temperature, moving subtly from a moderately hot 78.1°F (25.6°C) in August to an agreeable 71.6°F (22°C). During the month of September, Northfield's nighttime temperature lowers to an average of 60.3°F (15.7°C).Humidity
In September, the average relative humidity is 74%.Rainfall
In September, the rain falls for 14.8 days. Throughout September, 2.87" (73mm) of precipitation is accumulated. Throughout the year, there are 164.7 rainfall days, and 35.28" (896mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day in Northfield is 12h and 28min.On the first day of September, sunrise is at 6:17 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:33 pm CDT.
Sunshine
In Northfield, the average sunshine in September is 9h.UV index
In Northfield, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Ensure safety - Sun damage prevention is strongly urged. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Northfield, IL
- Average high temperature in September: 71.6°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is January (28.8°F).
- Average low temperature in September: 60.3°F
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Northfield, 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
Northfield, IL
- Average wind speed in September: 8.6mph
The windiest month (with the highest average wind speed) is January (11.5mph).
The calmest month (with the lowest average wind speed) is August (7.1mph).
Average humidity in September
Northfield, IL
- Average humidity in September: 74%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Northfield, IL
- Average rainfall in September: 2.87"
The wettest months (with the highest rainfall) are May and June (4.57").
The driest month (with the least rainfall) is December (1.65").
Average rainfall days in September
Northfield, IL
- Average rainfall days in September: 14.8 days
The month with the highest number of rainy days is May (19.1 days).
The month with the least rainy days is February (6.1 days).
Average snowfall in September
Northfield, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.84").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Northfield, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (13.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Northfield, IL
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 0min
The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Northfield, IL
- Average sunshine days in September: 11.7 days
The month with the most sunshine days is November (15.5 days).
The month with the least sunshine days is June (9.2 days).
Average UV index in September
Northfield, IL
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Northfield, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 28).
Average visibility in September
Northfield, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
