September weather forecastDelwood, IL
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Delwood, Illinois, with an average temperature fluctuating between 80.8°F (27.1°C) and 60.4°F (15.8°C).Temperature
The initiation of September sees an average high-temperature of a still moderately hot 80.8°F (27.1°C), showing minor variations from the previous month. Delwood reports an average low-temperature of 60.4°F (15.8°C) during the nights of September.Heat index
During September, the heat index is evaluated at 84.2°F (29°C). If one persists in activity during exposure, it could induce weariness and subsequently, heat cramps.It is essential to grasp that the heat index's numbers are for shade and light wind settings. The heat index can potentially augment by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'real feel', arises from combining readings of air temperature and relative moisture content. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Remember, direct sunlight exposure can heighten the heat impact and might increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly important for children. Youngsters frequently overlook the need for breaks and fluid intake. Thirst is an advanced sign of dehydration - thereby highlighting the importance of keeping hydrated, particularly during long physical activities.
Humidity
In Delwood, the average relative humidity in September is 73%.Rainfall
September is the month with the least rainfall. Rain falls for 10.5 days and accumulates 1.57" (40mm) of precipitation.Snowfall
In Delwood, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 25min.On the first day of September in Delwood, sunrise is at 6:25 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:38 pm CDT.
Sunshine
The average sunshine in September is 9.2h.UV index
In Delwood, Illinois, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Undertake protective steps - Recommendations to avoid sunburn are issued. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Delwood, IL
- Average high temperature in September: 80.8°F
The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is January (39.7°F).
- Average low temperature in September: 60.4°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in September
Delwood, 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
Delwood, IL
- Average wind speed in September: 6.4mph
The windiest months (with the highest average wind speed) are January and February (9.4mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in September
Delwood, IL
- Average humidity in September: 73%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Delwood, IL
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is April (4.8").
The driest month (with the least rainfall) is September (1.57").
Average rainfall days in September
Delwood, IL
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is May (18.5 days).
The month with the least rainy days is November (9.7 days).
Average snowfall in September
Delwood, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.73").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Delwood, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.3 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
Delwood, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in September: 9h and 12min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in September
Delwood, IL
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is October (19.5 days).
The month with the least sunshine days is May (9.9 days).
Average UV index in September
Delwood, 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 and December (UV index 2).
Average cloud cover in September
Delwood, IL
- Average cloud cover in September: 28
The months with the most cloud cover are January and February (Cloud cover 51).
The months with the least cloud cover are June and September (Cloud cover 28).
Average visibility in September
Delwood, 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).





