September weather forecastMounds, IL
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Mounds, Illinois, with an average temperature ranging between min 61.9°F (16.6°C) and max 81.5°F (27.5°C).Temperature
The arrival of September brings an average high-temperature of a warm 81.5°F (27.5°C), subtly diverging from August's 86.4°F (30.2°C). Mounds's nighttime temperature in September falls to an average of 61.9°F (16.6°C).Heat index
September's heat index is computed to be a tropical 86°F (30°C). If one stays active during extended exposure, it might induce fatigue and result in heat cramps.Heat index data is primarily for areas with shade and subjected to light winds. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', combines air temperature and relative humidity to represent a human perceived temperature equivalent. Elements such as metabolic variations, being pregnant, and physical activity can impact one's weather perception. Direct exposure to sun rays can potentially augment the heat sensation, elevating the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.
Humidity
In Mounds, the average relative humidity in September is 72%.Rainfall
The month with the least rainfall in Mounds is September, when the rain falls for 11.4 days and typically collects 1.42" (36mm) of precipitation.Snowfall
In Mounds, snow does not fall in May through September.Daylight
In Mounds, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:41 pm CDT.
Sunshine
The average sunshine in September in Mounds is 9.6h.UV index
In Mounds, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: An average UV index of 5 in September transforms into this advice:
Heed the precautions - Suggestions to avoid sunburn are made. To protect against the Sun's most potent rays, avoid direct exposure around midday. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mounds, IL
- Average high temperature in September: 81.5°F
The warmest month (with the highest average high temperature) is July (88.2°F).
The month with the lowest average high temperature is January (41.2°F).
- Average low temperature in September: 61.9°F
The month with the highest average low temperature is July (69.8°F).
The coldest month (with the lowest average low temperature) is January (28.4°F).
Average pressure in September
Mounds, IL
- Average pressure in September: 30.02"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
Mounds, IL
- Average wind speed in September: 6.3mph
The windiest months (with the highest average wind speed) are January, February and March (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity in September
Mounds, IL
- Average humidity in September: 72%
The months with the highest relative humidity are February, March, May and December (78%).
The month with the lowest relative humidity is October (69%).
Average rainfall in September
Mounds, IL
- Average rainfall in September: 1.42"
The wettest month (with the highest rainfall) is April (4.21").
The driest month (with the least rainfall) is September (1.42").
Average rainfall days in September
Mounds, IL
- Average rainfall days in September: 11.4 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (9.8 days).
Average snowfall in September
Mounds, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.5").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Mounds, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.8 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
Mounds, 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 42min).
- Average sunshine in September: 9h and 36min
The month with the most sunshine is June (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Mounds, IL
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is October (18.5 days).
The month with the least sunshine days is May (12.3 days).
Average UV index in September
Mounds, 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
Mounds, IL
- Average cloud cover in September: 27
The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is June (Cloud cover 26).
Average visibility in September
Mounds, 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).
