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
The start of September sees the average high-temperature at a still hot 86.7°F (30.4°C), showing little difference from August's 91.2°F (32.9°C). Decatur records an average low of 66.9°F (19.4°C) throughout the nights in September.Heat index
During September, the heat index is computed to be a very hot 98.6°F (37°C). Greater preventive actions are needed, heat exhaustion and heat cramps are likely. Persistent activity could provoke heatstroke.The metrics for the heat index are tailored for both shady environments and light winds. Direct sunlight exposure may cause a 15 Fahrenheit (8 Celsius) degrees rise in the heat index.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is an estimation of the warmth sensation when considering humidity levels. The effect is personal, with varied weather perceptions among individuals due to differences in body mass, stature, and physical activity. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. In general, younger individuals are at greater risk than adults because they tend to sweat less. Also, having a larger skin surface to body size ratio and greater heat production due to their active behavior contribute to this danger.
The evaporation of sweat is a natural cooling mechanism of the human body, facilitated by perspiration. Elevated relative humidity diminishes evaporation, thereby reducing the body's ability to shed heat and creating a feeling of being too warm. Accumulating heat beyond the body's cooling measures leads to rising temperatures and potential ailments.
Humidity
In September, the average relative humidity is 74%.Rainfall
In September, the rain falls for 13.6 days. Throughout September, 2.8" (71mm) of precipitation is accumulated. In Decatur, during the entire year, the rain falls for 167.6 days and collects up to 36.54" (928mm) of precipitation.Snowfall
April through November are months without snowfall.Daylight
In Decatur, the average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:20 pm. On the last day of September, sunrise is at 6:50 am and sunset at 6:42 pm CDT.
Sunshine
In September, the average sunshine is 9.3h.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 exposure to the Sun's UV radiation for the average person.Note: The daily high UV index of 5 during September translates into the following recommendations:
Take precautions - Protection against sunburn is recommended. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is September in Decatur?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Decatur have in September?
When are sunrise and sunset in September?
How many hours of sunshine does Decatur have in September?
What is the UV index reading in September?
Average temperature in September
Decatur, MS
- Average high temperature in September: 86.7°F
The warmest month (with the highest average high temperature) is July (91.4°F).
The month with the lowest average high temperature is January (54.5°F).
- Average low temperature in September: 66.9°F
The month with the highest average low temperature is August (71.8°F).
The coldest month (with the lowest average low temperature) is January (37.8°F).
Average pressure in September
Decatur, MS
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).
Average wind speed in September
Decatur, MS
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is February (7.8mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).
Average humidity in September
Decatur, MS
- Average humidity in September: 74%
The month with the highest relative humidity is December (81%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Decatur, MS
- Average rainfall in September: 2.8"
The wettest month (with the highest rainfall) is December (3.7").
The driest month (with the least rainfall) is November (2.09").
Average rainfall days in September
Decatur, MS
- Average rainfall days in September: 13.6 days
The month with the highest number of rainy days is July (20.3 days).
The month with the least rainy days is November (8.9 days).
Average snowfall in September
Decatur, MS
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.43").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Decatur, MS
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.8 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Decatur, MS
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 12min).
The month with the shortest days is December (Average daylight: 10h and 6min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 4h and 54min).
Average sunshine days in September
Decatur, MS
- Average sunshine days in September: 14.6 days
The month with the most sunshine days is October (20.2 days).
The month with the least sunshine days is July (9 days).
Average UV index in September
Decatur, MS
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January and December (UV index 3).
Average cloud cover in September
Decatur, MS
- Average cloud cover in September: 30
The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is October (Cloud cover 29).
Average visibility in September
Decatur, MS
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, September, October, November and December (6mi).
The months with the lowest visibility are May, July and August (5mi).
Decatur, Mississippi, USA
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