Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September experiences an average high-temperature of a still moderately hot 79°F (26.1°C), barely different from August's 83.8°F (28.8°C). In Fairfield, the average low-temperature during the month of September is a mild 60.4°F (15.8°C).Humidity
The average relative humidity in September is 74%.Rainfall
September is the month with the least rainfall. Rain falls for 13.5 days and accumulates 2.05" (52mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In Fairfield, Illinois, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:22 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:37 pm CDT.
Sunshine
The average sunshine in September is 9.1h.UV index
In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 5 in September converts into the following recommendations:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Fairfield in September?
What is the average humidity in September in Fairfield?
What is the driest month?
How many days does it rain in September?
When it does not snow?
How many hours of daylight does Fairfield have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Fairfield, IL
- Average high temperature in September: 79°F
The warmest month (with the highest average high temperature) is July (85.1°F).
The month with the lowest average high temperature is January (37.8°F).
- Average low temperature in September: 60.4°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in September
Fairfield, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Fairfield, IL
- Average wind speed in September: 6.7mph
The windiest months (with the highest average wind speed) are February and March (9.9mph).
The calmest month (with the lowest average wind speed) is July (5.9mph).
Average humidity in September
Fairfield, IL
- Average humidity in September: 74%
The months with the highest relative humidity are May and July (79%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Fairfield, IL
- Average rainfall in September: 2.05"
The wettest month (with the highest rainfall) is April (4.96").
The driest month (with the least rainfall) is September (2.05").
Average rainfall days in September
Fairfield, IL
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is May (19.8 days).
The month with the least rainy days is January (8.7 days).
Average snowfall in September
Fairfield, IL
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (2.01").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Fairfield, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.7 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
Fairfield, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in September
Fairfield, IL
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is October (17.9 days).
The month with the least sunshine days is May (9 days).
Average UV index in September
Fairfield, IL
- Average UV index in September: 5
The months with the highest UV index are May, 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
Fairfield, IL
- Average cloud cover in September: 29
The months with the most cloud cover are January and February (Cloud cover 51).
The months with the least cloud cover are June and August (Cloud cover 28).
Average visibility in September
Fairfield, 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).
Fairfield, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location