September weather forecastSpillertown, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Spillertown, Illinois, with an average temperature varying between 60.4°F (15.8°C) and 80.8°F (27.1°C).Temperature
Spillertown's shift from August to September is accompanied by an average high-temperature of a still moderately hot 80.8°F (27.1°C), a slight deviation from 85.6°F (29.8°C). Throughout September, the nighttime temperature averages to a refreshing 60.4°F (15.8°C).Heat index
Throughout September, the heat index is computed to be 84.2°F (29°C). If exposure and ongoing activity persist, they might induce a state of tiredness and heat cramps.Data suggests that the heat index is set for environments in shade and with a light wind. Exposure to the sun directly might heighten the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is the result of factoring in humidity to the air temperature, indicating perceived warmth. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. In direct sunlight, the heat's impact can be heightened, potentially leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Young ones often underestimate the need for rest and rehydration. Thirst appears late in dehydration - hence, it is important to keep hydrated, particularly during prolonged physical activities.
Humidity
In September, the average relative humidity is 73%.Rainfall
The month with the least rainfall is September, when the rain falls for 10.5 days and typically collects 1.1" (28mm) of precipitation.Snowfall
In Spillertown, snow does not fall in May through September.Daylight
In Spillertown, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:39 pm CDT.
Sunshine
In Spillertown, the average sunshine in September is 9.3h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: An average UV index of 5 in September transforms into this advice:
Undertake protective steps - Recommendations to avoid sunburn are issued. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Spillertown, IL
- Average high temperature in September: 80.8°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (39.6°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 (26.1°F).
Average pressure in September
Spillertown, 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
Spillertown, IL
- Average wind speed in September: 6.3mph
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
Spillertown, 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 (71%).
Average rainfall in September
Spillertown, IL
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is April (3.11").
The driest month (with the least rainfall) is September (1.1").
Average rainfall days in September
Spillertown, IL
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is July (15.3 days).
The month with the least rainy days is November (7.8 days).
Average snowfall in September
Spillertown, IL
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (0.94").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Spillertown, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.3 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
Spillertown, 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 18min
The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in September
Spillertown, IL
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is October (20.6 days).
The month with the least sunshine days is July (12.9 days).
Average UV index in September
Spillertown, 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
Spillertown, IL
- Average cloud cover in September: 28
The month with the most cloud cover is February (Cloud cover 51).
The months with the least cloud cover are June, August and September (Cloud cover 28).
Average visibility in September
Spillertown, 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).
