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
September signals a slight drop in average high-temperature, sliding from August's moderately hot 85.6°F (29.8°C) to a still warm 79.7°F (26.5°C). During September, an average low-temperature of 59.9°F (15.5°C) is observed.Humidity
In Mehlville, the average relative humidity in September is 73%.Rainfall
In September, the rain falls for 12.6 days. Throughout September, 2.13" (54mm) of precipitation is accumulated. In Mehlville, during the entire year, the rain falls for 146.1 days and collects up to 32.36" (822mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September, sunrise is at 6:31 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:56 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 value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum daily UV index of 5 during September translates into the following directions:
Ensure safety - Sun damage prevention is strongly urged. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
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?
How many hours of daylight does Mehlville have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Mehlville have in September?
What is the UV index intensity in September in Mehlville?
Average temperature in September
Mehlville, MO
- Average high temperature in September: 79.7°F
The warmest month (with the highest average high temperature) is July (86.9°F).
The month with the lowest average high temperature is January (37.9°F).
- Average low temperature in September: 59.9°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 (25°F).
Average pressure in September
Mehlville, 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
Mehlville, MO
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in September
Mehlville, MO
- Average humidity in September: 73%
The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Mehlville, MO
- Average rainfall in September: 2.13"
The wettest month (with the highest rainfall) is May (3.94").
The driest months (with the least rainfall) are February and November (1.77").
Average rainfall days in September
Mehlville, MO
- Average rainfall days in September: 12.6 days
The month with the highest number of rainy days is July (16.9 days).
The months with the least rainy days are January and February (6.8 days).
Average snowfall in September
Mehlville, MO
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.6").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Mehlville, MO
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (4.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Mehlville, 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 month with the most sunshine is June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Mehlville, MO
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is June (11.6 days).
Average UV index in September
Mehlville, 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, February and December (UV index 2).
Average cloud cover in September
Mehlville, MO
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in September
Mehlville, 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).
Mehlville, Missouri, USA
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