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
With the arrival of September, Decatur notices a mild change in the average high-temperature, sliding from August's warm 78.4°F (25.8°C) to an agreeable 72.7°F (22.6°C). Decatur records an average temperature drop to a fresh 54.5°F (12.5°C) in September.Humidity
In Decatur, the average relative humidity in September is 79%.Rainfall
In September, the rain falls for 12.8 days. Throughout September, 1.57" (40mm) of precipitation is accumulated. In Decatur, during the entire year, the rain falls for 139.4 days and collects up to 20" (508mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Decatur, the average length of the day in September is 12h and 28min.On the first day of September in Decatur, sunrise is at 7:10 am and sunset at 8:17 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 7:26 pm EDT.
Sunshine
The average sunshine in September is 8.1h.UV index
In September, the average daily maximum UV index 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 average person.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in Decatur in September?
How many hours of daylight does Decatur have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Decatur, MI
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (28.9°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (61.9°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Decatur, MI
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January, March and November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Decatur, MI
- Average wind speed in September: 7.2mph
The windiest month (with the highest average wind speed) is January (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).
Average humidity in September
Decatur, MI
- Average humidity in September: 79%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are April and October (77%).
Average rainfall in September
Decatur, MI
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is June (2.6").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in September
Decatur, MI
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is May (15.4 days).
The month with the least rainy days is February (4.8 days).
Average snowfall in September
Decatur, MI
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.29").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Decatur, MI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (17.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Decatur, MI
- Average daylight in September: 12h and 3min
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: 8h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 2h and 36min).
Average sunshine days in September
Decatur, MI
- Average sunshine days in September: 14.3 days
The month with the most sunshine days is March (14.4 days).
The month with the least sunshine days is January (9.8 days).
Average UV index in September
Decatur, MI
- Average UV index in September: 4
The months with the highest UV index are June and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Decatur, MI
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 75).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in September
Decatur, MI
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and February (5mi).
Decatur, Michigan, USA
Weather forecast for your location
2. Allow the app to use your location