September weather forecast
Mount Vernon, MO

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Weather in September

September, the first month of the autumn in Mount Vernon, is also a moderately hot month, with an average temperature varying between 60.6°F (15.9°C) and 79.9°F (26.6°C).

Temperature

Mount Vernon observes a small decrease in the average high-temperature with the arrival of September, falling from August's tropical 87.1°F (30.6°C) to a warm 79.9°F (26.6°C). Nightly temperatures in Mount Vernon drop to an average low of 60.6°F (15.9°C) in September.

Humidity

The average relative humidity in September in Mount Vernon is 74%.

Rainfall

In Mount Vernon, Missouri, in September, during 14.2 rainfall days, 2.68" (68mm) of precipitation is typically accumulated. In Mount Vernon, Missouri, 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 Mount Vernon, Missouri, the average length of the day in September 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, in Mount Vernon, sunrise is at 7:10 am and sunset at 6:59 pm CDT.

Sunshine

In Mount Vernon, Missouri, the average sunshine in September is 9.4h.

UV index

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for the average person.
Note: In September, a regular UV index of 5 translates into these guidelines:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
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Frequently asked questions

What are September temperatures in Mount Vernon?

In Mount Vernon, 79.9°F (26.6°C) is the average high-temperature and 60.6°F (15.9°C) is the average low-temperature during September. The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, in August is estimated at 98.6°F (37°C).

What is the average humidity in September in Mount Vernon?

In September, the average relative humidity in Mount Vernon is 74%.

How much does it rain in Mount Vernon in September?

In Mount Vernon, during September, the rain falls for 14.2 days and regularly aggregates up to 2.68" (68mm) of precipitation.

When it does not snow in Mount Vernon?

In Mount Vernon, Missouri, snow does not fall in June through October.

What is the average length of the day in September in Mount Vernon?

The average day length in September is 12h and 25min.

When is the sunrise / sunset in September in Mount Vernon?

In September, on the first day of the month, sunrise is at 6:46 am and sunset at 7:43 pm. On the last day of the month, in Mount Vernon, Missouri, sunrise is at 7:10 am and sunset at 6:59 pm CDT.

How many hours of sunshine does Mount Vernon have in September?

The average sunshine duration in September in Mount Vernon is 9.4h.

How high is the UV index in September in Mount Vernon?

The average daily maximum UV index in September in Mount Vernon, Missouri, is 5. A UV Index of 3 to 5 symbolizes a medium health risk from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Mount Vernon, MO

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).

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Average pressure in September
Mount Vernon, MO

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).

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Average wind speed in September
Mount Vernon, MO

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).

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Average humidity in September
Mount Vernon, MO

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%).

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Average rainfall in September
Mount Vernon, MO

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").

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Average rainfall days in September
Mount Vernon, MO

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).

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Average snowfall in September
Mount Vernon, MO

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").

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Average snowfall days in September
Mount Vernon, MO

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).

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Average daylight in September /
Average sunshine in September
Mount Vernon, MO

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).

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Average sunshine days in September
Mount Vernon, MO

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).

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Average UV index in September
Mount Vernon, MO

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).

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Average cloud cover in September
Mount Vernon, MO

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).

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Average visibility in September
Mount Vernon, MO

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).

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Mount Vernon, Missouri, USA

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