September weather forecast
Valley Park, MO

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Weather in September

September, the first month of the autumn in Valley Park, is also a moderately hot month, with an average temperature varying between 80.1°F (26.7°C) and 60.1°F (15.6°C).

Temperature

Valley Park's September weather features a light decline in high-temperatures, reducing from a hot 86.5°F (30.3°C) in August to a warm 80.1°F (26.7°C). Valley Park's average low-temperature in September is measured at a refreshing 60.1°F (15.6°C).

Humidity

In September, the average relative humidity is 72%.

Rainfall

In Valley Park, in September, during 11.9 rainfall days, 2.17" (55mm) of precipitation is typically accumulated. Throughout the year, there are 141.7 rainfall days, and 32.01" (813mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through March, September, November and December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, there are 18.9 snowfall days, and 7.2" (183mm) of snow is accumulated.

Daylight

In Valley Park, Missouri, the average length of the day in September is 12h and 25min.
On the first day of September, sunrise is at 6:31 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:45 pm CDT.

Sunshine

In September, the average sunshine is 9.4h.

UV index

The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.
Note: In September, the average maximum UV index of 5 translates into the following recommendations:
Take precautions - Protection against skin and eye damage is obliged. To guard against the harmful effects of the Sun, minimize exposure during midday. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Updated: Jun 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

In Valley Park, 80.1°F (26.7°C) is the average high-temperature and 60.1°F (15.6°C) is the average low-temperature during September. The average heat index (a.k.a. 'feels like', 'apparent temperature'), which combines air temperature and relative humidity, in August is estimated at 98.6°F (37°C).

What is the average humidity in September?

The average relative humidity in September is 72%.

How many days does it rain in September?

In September, the rain falls for 11.9 days. Throughout September, 2.17" (55mm) of precipitation is accumulated.

When does it start to snow?

September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow.

What is the average length of the day in September?

In September, the average day length is 12h and 25min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:31 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:45 pm CDT.

How long on average sun shines in September?

The average sunshine duration in September is 9.4h.

How high is the UV index in September?

In Valley Park, Missouri, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability 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
Valley Park, MO

Average temperature in September - Valley Park, MO
  • Average high temperature in September: 80.1°F

The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (38.1°F).

  • Average low temperature in September: 60.1°F

The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (24.6°F).

Average pressure in September
Valley Park, MO

Average pressure in September - Valley Park, MO
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in September
Valley Park, MO

Average wind speed in September - Valley Park, MO
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is January (8.9mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

Average humidity in September
Valley Park, MO

Average humidity in September - Valley Park, MO
  • Average humidity in September: 72%

The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is October (71%).

Average rainfall in September
Valley Park, MO

Average rainfall in September - Valley Park, MO
  • Average rainfall in September: 2.17"

The wettest month (with the highest rainfall) is May (4.09").
The driest month (with the least rainfall) is February (1.54").

Average rainfall days in September
Valley Park, MO

Average rainfall days in September - Valley Park, MO
  • Average rainfall days in September: 11.9 days

The month with the highest number of rainy days is May (16.9 days).
The month with the least rainy days is January (6.3 days).

Average snowfall in September
Valley Park, MO

Average snowfall in September - Valley Park, MO
  • Average snowfall in September: 0.04"

The month with the highest snowfall is January (2.52").
The months with the least snowfall are April, May, June, July, August and October (0").

Average snowfall days in September
Valley Park, MO

Average snowfall days in September - Valley Park, MO
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is January (6.7 days).
The months with the least snowfall days are April, May, June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Valley Park, MO

Average daylight in September / Average sunshine in September - Valley Park, MO
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in September: 9h and 2min

The months with the most sunshine are June and July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).

Average sunshine days in September
Valley Park, MO

Average sunshine days in September - Valley Park, MO
  • Average sunshine days in September: 16.3 days

The month with the most sunshine days is December (20.1 days).
The months with the least sunshine days are May and July (12.6 days).

Average UV index in September
Valley Park, MO

Average UV index in September - Valley Park, MO
  • Average UV index in September: 5

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
Valley Park, MO

Average cloud cover in September - Valley Park, MO
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are June, July and August (Cloud cover 29).

Average visibility in September
Valley Park, MO

Average visibility in September - Valley Park, 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).

Valley Park, Missouri, USA

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