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
The arrival of September is marked by a minor reduction in average high-temperature, sliding from a warm 83.7°F (28.7°C) in August to a still moderately hot 78.1°F (25.6°C). During September, Grantfork records an average temperature of 59.7°F (15.4°C) at night.Humidity
The average relative humidity in September is 75%.Rainfall
In Grantfork, in September, it is raining for 9.5 days, with typically 0.59" (15mm) of accumulated precipitation. In Grantfork, Illinois, during the entire year, the rain falls for 110.6 days and collects up to 12.01" (305mm) of precipitation.Snowfall
April through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, sunrise is at 6:28 am and sunset at 7:28 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:42 pm CDT.
Sunshine
The average sunshine in September is 9.5h.UV index
The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 transforms into these recommendations:
Heed the precautions - Suggestions to avoid sunburn are made. To avoid the Sun's strongest rays, limit exposure around the mid-day period. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Grantfork?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Grantfork have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Grantfork, IL
- Average high temperature in September: 78.1°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (36.9°F).
- Average low temperature in September: 59.7°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 (23.7°F).
Average pressure in September
Grantfork, 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 (29.92"Hg).
Average wind speed in September
Grantfork, IL
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is January (9.8mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity in September
Grantfork, IL
- Average humidity in September: 75%
The months with the highest relative humidity are July and August (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Grantfork, IL
- Average rainfall in September: 0.59"
The wettest month (with the highest rainfall) is May (1.46").
The driest month (with the least rainfall) is February (0.55").
Average rainfall days in September
Grantfork, IL
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is May (13.1 days).
The months with the least rainy days are January and December (5.9 days).
Average snowfall in September
Grantfork, IL
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.94").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in September
Grantfork, IL
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (4.8 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
Grantfork, 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 3min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The months with the least sunshine are January and February (Average sunshine: 4h and 36min).
Average sunshine days in September
Grantfork, IL
- Average sunshine days in September: 18.3 days
The month with the most sunshine days is December (21.8 days).
The month with the least sunshine days is July (14.5 days).
Average UV index in September
Grantfork, 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
Grantfork, IL
- Average cloud cover in September: 28
The months with the most cloud cover are January and February (Cloud cover 50).
The months with the least cloud cover are June, July, August and September (Cloud cover 28).
Average visibility in September
Grantfork, 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).
Grantfork, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location