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
Grayville experiences a transition to a still warm 79.2°F (26.2°C) in average high-temperatures with the arrival of September, not greatly differing from August's 84°F (28.9°C). In September, the temperature in Grayville drops to an average of 60.8°F (16°C) at night.Humidity
The average relative humidity in September is 73%.Rainfall
September is the month with the least rainfall. Rain falls for 12.6 days and accumulates 1.97" (50mm) of precipitation.Snowfall
May through October are months without snowfall in Grayville.Daylight
In Grayville, Illinois, the average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:22 am and sunset at 7:21 pm. On the last day of September, sunrise is at 6:47 am and sunset at 6:35 pm CDT.
Sunshine
In Grayville, the average sunshine in September is 9.1h.UV index
In Grayville, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 5 in September translates into these instructions:
Take precautions - Protection against skin and eye damage is obliged. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Grayville in September?
What is the average humidity in September in Grayville?
What is the driest month in Grayville?
How much does it rain in Grayville in September?
When it does not snow in Grayville?
What is the average length of the day in September in Grayville?
When are sunrise and sunset in September in Grayville?
How many hours of sunshine does Grayville have in September?
How high is the UV index in September in Grayville?
Average temperature in September
Grayville, IL
- Average high temperature in September: 79.2°F
The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is January (38.1°F).
- Average low temperature in September: 60.8°F
The month with the highest average low temperature is July (68°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).
Average pressure in September
Grayville, 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
Grayville, IL
- Average wind speed in September: 6.8mph
The windiest months (with the highest average wind speed) are January and February (10.1mph).
The calmest month (with the lowest average wind speed) is July (5.9mph).
Average humidity in September
Grayville, IL
- Average humidity in September: 73%
The month with the highest relative humidity is July (80%).
The month with the lowest relative humidity is October (69%).
Average rainfall in September
Grayville, IL
- Average rainfall in September: 1.97"
The wettest month (with the highest rainfall) is April (5.2").
The driest month (with the least rainfall) is September (1.97").
Average rainfall days in September
Grayville, IL
- Average rainfall days in September: 12.6 days
The month with the highest number of rainy days is May (19.6 days).
The month with the least rainy days is January (9.8 days).
Average snowfall in September
Grayville, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.54").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Grayville, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.6 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
Grayville, 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 36min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in September
Grayville, IL
- Average sunshine days in September: 15 days
The month with the most sunshine days is October (18.2 days).
The month with the least sunshine days is May (8.8 days).
Average UV index in September
Grayville, 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
Grayville, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is June (Cloud cover 27).
Average visibility in September
Grayville, 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).
Grayville, Illinois, USA
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