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
As September takes hold, the average high-temperature is a still moderately hot 75.4°F (24.1°C), nearly mirroring that of the previous month. Throughout the month of September, Alpha witnesses an average low-temperature of 56.5°F (13.6°C).Humidity
The average relative humidity in September is 76%.Rainfall
In Alpha, in September, during 11.1 rainfall days, 2.13" (54mm) of precipitation is typically accumulated. In Alpha, during the entire year, the rain falls for 143.6 days and collects up to 27.99" (711mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In Alpha, Illinois, the average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:28 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:44 pm CDT.
Sunshine
The average sunshine in September in Alpha is 9.3h.UV index
In Alpha, Illinois, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum UV index of 4 during September leads to these instructions:
Take necessary precautions - Protection from skin and eye injury is mandatory. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Alpha in September?
What is the average humidity in September in Alpha?
How many days does it rain in September in Alpha?
When it does not snow in Alpha?
Does it snow in Alpha in September?
What is the average length of the day in September in Alpha?
When are sunrise and sunset in September in Alpha?
How long on average sun shines in September in Alpha?
What is the UV index reading in September in Alpha?
Average temperature in September
Alpha, IL
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (28.4°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in September
Alpha, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Alpha, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in September
Alpha, IL
- Average humidity in September: 76%
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Alpha, IL
- Average rainfall in September: 2.13"
The wettest month (with the highest rainfall) is May (4.45").
The driest month (with the least rainfall) is December (1.26").
Average rainfall days in September
Alpha, IL
- Average rainfall days in September: 11.1 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is January (5 days).
Average snowfall in September
Alpha, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.09").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Alpha, IL
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (11.2 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Alpha, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Alpha, IL
- Average sunshine days in September: 17.8 days
The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is May (10.4 days).
Average UV index in September
Alpha, IL
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Alpha, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Alpha, 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).
Alpha, Illinois, USA
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