September weather forecastPetersburg, IL
September
Weather in September
September, the first month of the autumn in Petersburg, is still a warm month, with an average temperature fluctuating between 77.4°F (25.2°C) and 58.5°F (14.7°C).Temperature
The arrival of September sees a recorded average high-temperature of a still moderately hot 77.4°F (25.2°C), showing little divergence from the previous month's conditions. The average temperature during September nights is registered at a mild 58.5°F (14.7°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In Petersburg, during September, the rain falls for 11.9 days and regularly aggregates up to 2.87" (73mm) of precipitation. In Petersburg, during the entire year, the rain falls for 146.4 days and collects up to 30.67" (779mm) of precipitation.Snowfall
In Petersburg, snow does not fall in May through September.Daylight
The average length of the day in September in Petersburg is 12h and 26min.On the first day of September in Petersburg, sunrise is at 6:27 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:42 pm CDT.
Sunshine
The average sunshine in September in Petersburg is 9.1h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: The UV index of 5 during September leads to these advisories:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Petersburg, IL
- Average high temperature in September: 77.4°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in September: 58.5°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).
Average pressure in September
Petersburg, 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 (29.91"Hg).
Average wind speed in September
Petersburg, IL
- Average wind speed in September: 7.2mph
The windiest months (with the highest average wind speed) are January, February and April (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).
Average humidity in September
Petersburg, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Petersburg, IL
- Average rainfall in September: 2.87"
The wettest month (with the highest rainfall) is May (3.82").
The driest month (with the least rainfall) is December (1.5").
Average rainfall days in September
Petersburg, IL
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (6.2 days).
Average snowfall in September
Petersburg, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.02").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Petersburg, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.3 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
Petersburg, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 6min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Petersburg, IL
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (11.3 days).
Average UV index in September
Petersburg, IL
- Average UV index in September: 5
The months with the highest UV index are 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
Petersburg, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Petersburg, 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).
