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
In September, the average high-temperature marginally drops from a tropical 87.1°F (30.6°C) in August to a warm 79.9°F (26.6°C). Mount Vernon's temperature tends to fall to an average low of 60.6°F (15.9°C) during the nights of September.Humidity
In Mount Vernon, the average relative humidity in September is 74%.Rainfall
In Mount Vernon, in September, during 14.2 rainfall days, 2.68" (68mm) of precipitation is typically accumulated. In Mount Vernon, during the entire year, the rain falls for 155.3 days and collects up to 35.59" (904mm) of precipitation.Snowfall
June through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 25min.On the first day of the month, sunrise is at 6:46 am and sunset at 7:43 pm. On the last day of September, sunrise is at 7:10 am and sunset at 6:59 pm CDT.
Sunshine
The average sunshine in September is 9.4h.UV index
In Mount Vernon, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The daily high UV index of 5 in September translates into this advice:
Adopt protective measures - Suggestions to resist sunburn are offered. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
What is the average length of the day 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 intensity in September?
Average temperature in September
Mount Vernon, MO
- Average high temperature in September: 79.9°F
The warmest month (with the highest average high temperature) is July (88.7°F).
The month with the lowest average high temperature is January (42.3°F).
- Average low temperature in September: 60.6°F
The month with the highest average low temperature is July (68.9°F).
The coldest month (with the lowest average low temperature) is January (26.6°F).
Average pressure in September
Mount Vernon, MO
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The months with the lowest atmospheric pressure are April and June (29.93"Hg).
Average wind speed in September
Mount Vernon, MO
- Average wind speed in September: 7.1mph
The windiest months (with the highest average wind speed) are March and April (10.3mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).
Average humidity in September
Mount Vernon, MO
- Average humidity in September: 74%
The month with the highest relative humidity is May (78%).
The months with the lowest relative humidity are January, July, August and October (73%).
Average rainfall in September
Mount Vernon, MO
- Average rainfall in September: 2.68"
The wettest month (with the highest rainfall) is May (5.31").
The driest month (with the least rainfall) is February (1.69").
Average rainfall days in September
Mount Vernon, MO
- Average rainfall days in September: 14.2 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (7.3 days).
Average snowfall in September
Mount Vernon, MO
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.24").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Mount Vernon, MO
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (5.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Mount Vernon, MO
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 5h and 18min).
Average sunshine days in September
Mount Vernon, MO
- Average sunshine days in September: 13.5 days
The month with the most sunshine days is December (20.7 days).
The month with the least sunshine days is July (10.6 days).
Average UV index in September
Mount Vernon, MO
- 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
Mount Vernon, MO
- Average cloud cover in September: 29
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in September
Mount Vernon, MO
- 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).
Mount Vernon, Missouri, USA
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