September weather forecastWilliamsfield, IL
September
Weather in September
September, the first month of the autumn in Williamsfield, is also a moderately hot month, with an average temperature ranging between max 75.7°F (24.3°C) and min 56.7°F (13.7°C).Temperature
Williamsfield marks the start of September with an average high-temperature of a still warm 75.7°F (24.3°C), hinting at a slight fluctuation from August's 80.2°F (26.8°C). During September, Williamsfield experiences an average low-temperature of 56.7°F (13.7°C) at night.Humidity
The average relative humidity in September is 77%.Rainfall
In Williamsfield, during September, the rain falls for 9.3 days and regularly aggregates up to 1.1" (28mm) of precipitation. Throughout the year, in Williamsfield, there are 116.8 rainfall days, and 13.98" (355mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In September, the average length of the day in Williamsfield is 12h and 27min.On the first day of September, sunrise is at 6:27 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:43 pm CDT.
Sunshine
The average sunshine in September is 9.1h.UV index
In Williamsfield, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for ordinary individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Williamsfield, IL
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in September: 56.7°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).
Average pressure in September
Williamsfield, 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 (29.91"Hg).
Average wind speed in September
Williamsfield, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in September
Williamsfield, IL
- Average humidity in September: 77%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Williamsfield, IL
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is May (2.24").
The driest month (with the least rainfall) is January (0.59").
Average rainfall days in September
Williamsfield, IL
- Average rainfall days in September: 9.3 days
The month with the highest number of rainy days is May (15.2 days).
The months with the least rainy days are January and February (4.2 days).
Average snowfall in September
Williamsfield, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.81").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Williamsfield, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.6 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
Williamsfield, 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 18min).
- Average sunshine in September: 9h and 6min
The months with the most sunshine are June and July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Williamsfield, IL
- Average sunshine days in September: 18.3 days
The month with the most sunshine days is November (21.3 days).
The month with the least sunshine days is May (12.8 days).
Average UV index in September
Williamsfield, 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
Williamsfield, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in September
Williamsfield, 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).





