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 to September signals an average high-temperature of a still moderately hot 78.4°F (25.8°C), subtly varied from August's 83.7°F (28.7°C). Dow encounters an average low-temperature of 59.4°F (15.2°C) during September nights.Humidity
In Dow, the average relative humidity in September is 75%.Rainfall
In Dow, in September, it is raining for 11.5 days, with typically 1.57" (40mm) of accumulated precipitation. In Dow, during the entire year, the rain falls for 136.5 days and collects up to 23.11" (587mm) of precipitation.Snowfall
In Dow, Illinois, snow does not fall in April through October.Daylight
In Dow, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:31 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:45 pm CDT.
Sunshine
The average sunshine in September is 9.5h.UV index
In Dow, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 transforms into these recommendations:
Undertake protective steps - Recommendations to avoid sunburn are issued. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How many hours of sunshine does Dow have in September?
What is the UV index reading in September?
Average temperature in September
Dow, IL
- Average high temperature in September: 78.4°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (35.6°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 (22.6°F).
Average pressure in September
Dow, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Dow, 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
Dow, 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
Dow, IL
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is June (3.07").
The driest month (with the least rainfall) is January (1.06").
Average rainfall days in September
Dow, IL
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is January (5.9 days).
Average snowfall in September
Dow, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.17").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Dow, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.2 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
Dow, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
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 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Dow, IL
- Average sunshine days in September: 16.6 days
The month with the most sunshine days is January (20.3 days).
The months with the least sunshine days are May and June (12.3 days).
Average UV index in September
Dow, 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
Dow, IL
- Average cloud cover in September: 28
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are August and September (Cloud cover 28).
Average visibility in September
Dow, 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).
Dow, Illinois, USA
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