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 arrival of September denotes a barely perceptible change in the average high-temperatures to a still hot 88.2°F (31.2°C) from August's 91.6°F (33.1°C). Mount Vernon experiences a mean temperature of 70.7°F (21.5°C) during September nights.Heat index
In September, the average heat index is computed to be an extremely hot 104°F (40°C). Ensure additional precautions, heat exhaustion and heat cramps may be expected. Heatstroke could occur from sustained activity.Given the heat index, its values are aligned with shaded sites and gentle winds. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. The impact of weather on an individual can be subjective, affected by the person's activity and heat perception, which can vary due to elements including wind, clothing, and metabolic differences. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Typically, young kids are at a higher risk than adults since they sweat less. Also, the larger skin surface in proportion to their small bodies and the heightened heat production due to their active nature adds to their vulnerability.
The physiological way the human body responds to excessive heat is by inducing perspiration, using sweat evaporation as a cooling mechanism. With higher relative humidity, the rate of evaporation is reduced, resulting in increased heat retention in the body compared to drier air. Heat-related complications, like dehydration, can manifest if the body's heat gain exceeds its dissipation capacity.
Humidity
The average relative humidity in September is 75%.Rainfall
In Mount Vernon, in September, during 15.3 rainfall days, 2.48" (63mm) of precipitation is typically accumulated. Throughout the year, there are 156.2 rainfall days, and 33.35" (847mm) of precipitation is accumulated.Snowfall
March through December are months without snowfall in Mount Vernon.Daylight
In September, the average length of the day in Mount Vernon is 12h and 20min.On the first day of September in Mount Vernon, Alabama, sunrise is at 6:28 am and sunset at 7:15 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:38 pm CDT.
Sunshine
In September, the average sunshine is 9.4h.UV index
The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 6 during September translates into the following guidance:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. Remember that UV radiation from the Sun is strongest between 10 a.m. and 4 p.m. Make an effort to limit direct sun exposure during this time. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
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?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Mount Vernon have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Mount Vernon have in September?
What is the UV index reading in September in Mount Vernon?
Average temperature in September
Mount Vernon, AL
- Average high temperature in September: 88.2°F
The warmest month (with the highest average high temperature) is July (91.9°F).
The month with the lowest average high temperature is January (58.5°F).
- Average low temperature in September: 70.7°F
The month with the highest average low temperature is August (75°F).
The coldest month (with the lowest average low temperature) is January (41.9°F).
Average pressure in September
Mount Vernon, AL
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The months with the lowest atmospheric pressure are June and August (29.97"Hg).
Average wind speed in September
Mount Vernon, AL
- Average wind speed in September: 4.9mph
The windiest month (with the highest average wind speed) is April (6.6mph).
The calmest month (with the lowest average wind speed) is July (4.5mph).
Average humidity in September
Mount Vernon, AL
- Average humidity in September: 75%
The month with the highest relative humidity is December (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Mount Vernon, AL
- Average rainfall in September: 2.48"
The wettest months (with the highest rainfall) are July and August (4.57").
The driest month (with the least rainfall) is November (1.65").
Average rainfall days in September
Mount Vernon, AL
- Average rainfall days in September: 15.3 days
The month with the highest number of rainy days is July (22.8 days).
The month with the least rainy days is November (6.6 days).
Average snowfall in September
Mount Vernon, AL
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.2").
The months with the least snowfall are March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Mount Vernon, AL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.3 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
Mount Vernon, AL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 6min).
The month with the shortest days is December (Average daylight: 10h and 12min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 12min).
Average sunshine days in September
Mount Vernon, AL
- Average sunshine days in September: 13.5 days
The month with the most sunshine days is November (22.5 days).
The month with the least sunshine days is July (6.1 days).
Average UV index in September
Mount Vernon, AL
- Average UV index in September: 6
The months with the highest UV index are May, June, July and August (UV index 7).
The months with the lowest UV index are January and December (UV index 3).
Average cloud cover in September
Mount Vernon, AL
- Average cloud cover in September: 28
The month with the most cloud cover is December (Cloud cover 46).
The month with the least cloud cover is October (Cloud cover 25).
Average visibility in September
Mount Vernon, AL
- Average visibility in September: 6mi
The months with the highest visibility are January, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are February and December (5mi).
Mount Vernon, Alabama, USA
Weather forecast for your location
2. Allow the app to use your location