September weather forecastExeter, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Exeter, Illinois, with temperature in the range of an average low of 58.8°F (14.9°C) and an average high of 78.1°F (25.6°C).Temperature
The arrival of September suggests a slight decrease in the average high-temperature, moving from 83.5°F (28.6°C) in August to a still warm 78.1°F (25.6°C). Exeter's temperature lowers to a mean of 58.8°F (14.9°C) during the nights in September.Humidity
The average relative humidity in September is 74%.Rainfall
In Exeter, during September, the rain falls for 12.2 days and regularly aggregates up to 2.64" (67mm) of precipitation. Throughout the year, in Exeter, there are 155.4 rainfall days, and 31.69" (805mm) of precipitation is accumulated.Snowfall
In Exeter, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 26min.On the first day of September in Exeter, Illinois, sunrise is at 6:30 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:45 pm CDT.
Sunshine
In Exeter, the average sunshine in September is 9.4h.UV index
In Exeter, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the average person.Note: A typical high UV index of 5 in September suggests the following recommendations:
Guard yourself - Precautionary measures against sun damage are advocated. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Exeter, IL
- Average high temperature in September: 78.1°F
The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (33.8°F).
- Average low temperature in September: 58.8°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in September
Exeter, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Exeter, IL
- Average wind speed in September: 6.8mph
The windiest months (with the highest average wind speed) are January and April (9.9mph).
The calmest month (with the lowest average wind speed) is July (6mph).
Average humidity in September
Exeter, IL
- Average humidity in September: 74%
The month with the highest relative humidity is July (82%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Exeter, IL
- Average rainfall in September: 2.64"
The wettest month (with the highest rainfall) is May (4.02").
The driest months (with the least rainfall) are January, February and December (1.73").
Average rainfall days in September
Exeter, IL
- Average rainfall days in September: 12.2 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is February (7.2 days).
Average snowfall in September
Exeter, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.46").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Exeter, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.8 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
Exeter, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 24min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in September
Exeter, IL
- Average sunshine days in September: 15.4 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is June (8.6 days).
Average UV index in September
Exeter, 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
Exeter, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 30).
Average visibility in September
Exeter, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
