September weather forecastMount Vernon, AR
September
Weather in September
The first month of the autumn, September, is still a warm month in Mount Vernon, Arkansas, with temperature in the range of an average high of 83.7°F (28.7°C) and an average low of 63.1°F (17.3°C).Temperature
As August transitions into September, Mount Vernon sees a gentle drop in the average high-temperature, transitioning from a tropical 90.1°F (32.3°C) to a warm 83.7°F (28.7°C). In September, Mount Vernon reports a consistent average low-temperature of 63.1°F (17.3°C) during the nights.Heat index
The heat index for September is evaluated at a tropical 91.4°F (33°C). Implement heightened safety measures - risk of heat exhaustion and heat cramps is increased. Prolonged activity may result in heatstroke.Remember that heat index calculations are made for conditions in the shade with light wind. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', shows a temperature sensation when both heat and moisture conditions are combined. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. Consider the sun's direct rays and their impact; they can potentially increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Children often do not understand the need to rest and hydrate. Thirst is a late manifestation of dehydration - therefore, it is essential to stay hydrated, particularly during prolonged physical activities.
Humidity
The average relative humidity in September in Mount Vernon is 73%.Rainfall
September is the month with the least rainfall. Rain falls for 9.1 days and accumulates 0.67" (17mm) of precipitation.Snowfall
In Mount Vernon, Arkansas, snow does not fall in April through October.Daylight
In September, the average length of the day is 12h and 23min.On the first day of the month, sunrise is at 6:41 am and sunset at 7:34 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:53 pm CDT.
Sunshine
In September, the average sunshine is 9.6h.UV index
In Mount Vernon, 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: The maximum daily UV index, 5 in September, converts into the following recommendations:
Take necessary precautions - Protection from skin and eye injury is mandatory. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. 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
Average temperature in September
Mount Vernon, AR
- Average high temperature in September: 83.7°F
The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (46.9°F).
- Average low temperature in September: 63.1°F
The month with the highest average low temperature is July (70.3°F).
The coldest month (with the lowest average low temperature) is January (32.2°F).
Average pressure in September
Mount Vernon, AR
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Mount Vernon, AR
- Average wind speed in September: 5.1mph
The windiest months (with the highest average wind speed) are March and April (7.6mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).
Average humidity in September
Mount Vernon, AR
- Average humidity in September: 73%
The month with the highest relative humidity is March (79%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Mount Vernon, AR
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is July (1.61").
The driest month (with the least rainfall) is September (0.67").
Average rainfall days in September
Mount Vernon, AR
- Average rainfall days in September: 9.1 days
The month with the highest number of rainy days is July (13.3 days).
The month with the least rainy days is October (7.2 days).
Average snowfall in September
Mount Vernon, AR
- Average snowfall in September: 0"
The month with the highest snowfall is March (0.24").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Mount Vernon, AR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (1.5 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Mount Vernon, AR
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 9h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 12min).
Average sunshine days in September
Mount Vernon, AR
- Average sunshine days in September: 17.7 days
The month with the most sunshine days is October (21.6 days).
The month with the least sunshine days is July (14 days).
Average UV index in September
Mount Vernon, AR
- Average UV index in September: 5
The month with the highest UV index is June (UV index 7).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Mount Vernon, AR
- Average cloud cover in September: 27
The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is June (Cloud cover 26).
Average visibility in September
Mount Vernon, AR
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
