September weather forecastBlackstone, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Blackstone, Illinois, with temperature in the range of an average high of 75°F (23.9°C) and an average low of 56.5°F (13.6°C).Temperature
Blackstone's shift into September is marked by a subtle change to a still warm 75°F (23.9°C) from August's 79.7°F (26.5°C) in temperature. The nighttime temperature dips to a refreshing 56.5°F (13.6°C) on average during September.Humidity
The average relative humidity in September in Blackstone is 77%.Rainfall
In Blackstone, in September, during 12.1 rainfall days, 1.85" (47mm) of precipitation is typically accumulated. In Blackstone, during the entire year, the rain falls for 145 days and collects up to 25.08" (637mm) of precipitation.Snowfall
In Blackstone, snow does not fall in May through September.Daylight
In Blackstone, the average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:22 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:37 pm CDT.
Sunshine
In Blackstone, the average sunshine in September is 8.9h.UV index
The average daily maximum UV index in September in Blackstone is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: An average maximum UV index of 4 in September leads to these recommendations:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Blackstone, IL
- Average high temperature in September: 75°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (29.5°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).
Average pressure in September
Blackstone, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Blackstone, IL
- Average wind speed in September: 7.4mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Blackstone, IL
- Average humidity in September: 77%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Blackstone, IL
- Average rainfall in September: 1.85"
The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is December (1.18").
Average rainfall days in September
Blackstone, IL
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is July (18.1 days).
The month with the least rainy days is February (5.3 days).
Average snowfall in September
Blackstone, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.27").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Blackstone, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 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
Blackstone, IL
- Average daylight in September: 12h and 30min
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: 8h and 54min
The month with the most sunshine is June (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Blackstone, IL
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is July (9.2 days).
Average UV index in September
Blackstone, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Blackstone, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 59).
The months with the least cloud cover are August and September (Cloud cover 32).
Average visibility in September
Blackstone, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
