September weather forecastSavanna, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Savanna, Illinois, with an average temperature fluctuating between 73.4°F (23°C) and 54.5°F (12.5°C).Temperature
As September commences, the average high-temperature subtly reduces, transitioning from 79.2°F (26.2°C) in August to a still moderately hot 73.4°F (23°C). During the nights in September, Savanna experiences a consistent average temperature of 54.5°F (12.5°C).Humidity
The average relative humidity in September is 79%.Rainfall
In Savanna, in September, it is raining for 12.1 days, with typically 2.48" (63mm) of accumulated precipitation. In Savanna, during the entire year, the rain falls for 149.3 days and collects up to 29.76" (756mm) of precipitation.Snowfall
In Savanna, Illinois, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:33 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:43 pm CDT.
Sunshine
The average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the maximum UV index of 4 suggests these recommendations:
Ensure safety - Recommendations to avert sunburn are presented. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Savanna, IL
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (26.1°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).
Average pressure in September
Savanna, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Savanna, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Savanna, IL
- Average humidity in September: 79%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Savanna, IL
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is May (4.09").
The driest month (with the least rainfall) is February (1.38").
Average rainfall days in September
Savanna, IL
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is May (18.5 days).
The month with the least rainy days is February (4.4 days).
Average snowfall in September
Savanna, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.12").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Savanna, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Savanna, IL
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Savanna, IL
- Average sunshine days in September: 16 days
The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is June (9.6 days).
Average UV index in September
Savanna, 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
Savanna, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in September
Savanna, IL
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
