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
September's onset brings an average high-temperature of a moderately hot 83.1°F (28.4°C), showing a minute difference from August's 88.2°F (31.2°C). Decatur's nighttime temperature in September falls to an average of 63.7°F (17.6°C).Heat index
In September, the average heat index is evaluated at a hot 89.6°F (32°C). Fatigue might occur with continuous exposure and activity, potentially causing heat cramps.Be aware that heat index ratings are designed for shaded locations and minor breezes. Direct sunlight has the potential to heighten heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. The impact of weather is personal, differing among a variety of people based on differences in body mass, height, and the level of physical exertion. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Young children are more at risk than adults since they tend to sweat less. Moreover, their large skin surface in proportion to their small bodies and the high heat production due to their activities contribute to their vulnerability.
Humidity
In September, the average relative humidity is 74%.Rainfall
September and November are months with the least rain when the rain falls for 13.8 days and typically aggregates up to 2.48" (63mm) of rain.Snowfall
In Decatur, snow does not fall in April through October.Daylight
In Decatur, the average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 6:21 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:32 pm CDT.
Sunshine
The average sunshine in September is 8.8h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for average individuals.Note: In September, the maximum UV index of 5 transforms into these recommendations:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in September?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Decatur, AL
- Average high temperature in September: 83.1°F
The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is January (47.5°F).
- Average low temperature in September: 63.7°F
The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (33.3°F).
Average pressure in September
Decatur, AL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in September
Decatur, AL
- Average wind speed in September: 5.3mph
The windiest month (with the highest average wind speed) is February (8.6mph).
The calmest month (with the lowest average wind speed) is July (4.8mph).
Average humidity in September
Decatur, AL
- Average humidity in September: 74%
The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Decatur, AL
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is December (4.45").
The driest months (with the least rainfall) are September and November (2.48").
Average rainfall days in September
Decatur, AL
- Average rainfall days in September: 13.8 days
The month with the highest number of rainy days is July (20 days).
The month with the least rainy days is November (10.4 days).
Average snowfall in September
Decatur, AL
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (0.55").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Decatur, AL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.5 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
Decatur, AL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Decatur, AL
- Average sunshine days in September: 13.9 days
The month with the most sunshine days is October (19.2 days).
The month with the least sunshine days is July (8.8 days).
Average UV index in September
Decatur, AL
- 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 and December (UV index 2).
Average cloud cover in September
Decatur, AL
- Average cloud cover in September: 30
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is June (Cloud cover 29).
Average visibility in September
Decatur, AL
- 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).
Decatur, Alabama, USA
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