September weather forecastAnnapolis, IL
September
Weather in September
September, the first month of the autumn in Annapolis, is still a warm month, with an average temperature ranging between max 77.9°F (25.5°C) and min 59.5°F (15.3°C).Temperature
Annapolis experiences a transition to a still warm 77.9°F (25.5°C) in average high-temperatures with the arrival of September, not greatly differing from August's 82.2°F (27.9°C). Annapolis experiences a mean low-temperature of 59.5°F (15.3°C) during September.Humidity
In Annapolis, the average relative humidity in September is 75%.Rainfall
September is the month with the least rainfall in Annapolis. Rain falls for 11.8 days and accumulates 1.46" (37mm) of precipitation.Snowfall
May through October are months without snowfall in Annapolis, Illinois.Daylight
In Annapolis, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:20 am and sunset at 7:21 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:34 pm CDT.
Sunshine
In Annapolis, the average sunshine in September is 8.9h.UV index
The average daily maximum UV index in September in Annapolis is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for average individuals.Note: The daily maximum UV index of 5 in September interprets into the following advice:
Guard yourself - Avoiding sunburn is suggested. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Annapolis, IL
- Average high temperature in September: 77.9°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (36°F).
- Average low temperature in September: 59.5°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in September
Annapolis, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Annapolis, IL
- Average wind speed in September: 6.7mph
The windiest months (with the highest average wind speed) are January and February (10.1mph).
The calmest month (with the lowest average wind speed) is July (5.9mph).
Average humidity in September
Annapolis, IL
- Average humidity in September: 75%
The months with the highest relative humidity are July and August (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Annapolis, IL
- Average rainfall in September: 1.46"
The wettest month (with the highest rainfall) is April (4.13").
The driest month (with the least rainfall) is September (1.46").
Average rainfall days in September
Annapolis, IL
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (8.3 days).
Average snowfall in September
Annapolis, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.61").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Annapolis, 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, September and October (0 days).
Average daylight in September /
Average sunshine in September
Annapolis, IL
- Average daylight in September: 12h and 24min
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: 8h and 54min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Annapolis, IL
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is October (18.7 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in September
Annapolis, 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
Annapolis, IL
- Average cloud cover in September: 31
The months with the most cloud cover are January and February (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Annapolis, 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).
