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 shift from August to September includes a small decrease in the average high-temperature, from a warm 84°F (28.9°C) to a still moderately hot 78.6°F (25.9°C). East Alton, in the month of September, anticipates a consistent average low-temperature of 59.4°F (15.2°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In September, in East Alton, the rain falls for 11.8 days. Throughout September, 1.69" (43mm) of precipitation is accumulated. Throughout the year, there are 138 rainfall days, and 23.9" (607mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in East Alton.Daylight
The average length of the day in September in East Alton is 12h and 26min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:30 pm. On the last day of September, sunrise is at 6:56 am and sunset at 6:44 pm CDT.
Sunshine
The average sunshine in September in East Alton is 9.3h.UV index
In East Alton, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: In September, a daily maximum UV index of 5 leads to the following instructions:
Act with care - Obligation to protect against skin and eye damage is highlighted. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in East Alton in September?
What is the average humidity in September in East Alton?
How many days does it rain in September in East Alton?
When it does not snow in East Alton?
What is the average length of the day in September in East Alton?
When are sunrise and sunset in September in East Alton?
How many hours of sunshine does East Alton have in September?
How high is the UV index in September in East Alton?
Average temperature in September
East Alton, IL
- Average high temperature in September: 78.6°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in September: 59.4°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 (23.4°F).
Average pressure in September
East Alton, 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
East Alton, IL
- Average wind speed in September: 6.3mph
The windiest months (with the highest average wind speed) are January and February (9.6mph).
The calmest month (with the lowest average wind speed) is July (5.7mph).
Average humidity in September
East Alton, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
East Alton, IL
- Average rainfall in September: 1.69"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is February (1.14").
Average rainfall days in September
East Alton, IL
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is January (5.6 days).
Average snowfall in September
East Alton, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.61").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
East Alton, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (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
East Alton, 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 2min
The month with the most sunshine is June (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 4h and 30min).
Average sunshine days in September
East Alton, IL
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is July (12.3 days).
Average UV index in September
East Alton, 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
East Alton, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are June, July and August (Cloud cover 29).
Average visibility in September
East Alton, 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).
East Alton, Illinois, USA
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