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
The onset of September results in a small decrease in the average high-temperature, moderately receding from a moderately hot 84.6°F (29.2°C) in August to a still warm 77.4°F (25.2°C). Throughout the month of September, the average temperature dips to a moderate 58.3°F (14.6°C) at night.Humidity
The average relative humidity in September is 77%.Rainfall
September is the month with the least rainfall. Rain falls for 13.7 days and accumulates 1.93" (49mm) of precipitation.Snowfall
May through September are months without snowfall in Saint Louis.Daylight
The average length of the day in September is 12h and 26min.On the first day of September in Saint Louis, sunrise is at 6:40 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:54 pm EDT.
Sunshine
In Saint Louis, the average sunshine in September is 8.9h.UV index
The average daily maximum UV index in September in Saint Louis is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for the average person.Note: In September, the maximum UV index of 4 transforms into these recommendations:
Take necessary precautions - Defending against sun damage is advocated. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Frequently asked questions
What is the average September temperature in Saint Louis?
What is the average humidity in September in Saint Louis?
What is the driest month in Saint Louis?
How much does it rain in Saint Louis in September?
When it does not snow in Saint Louis?
Does it snow in Saint Louis in September?
How many hours of daylight does Saint Louis have in September?
What time are sunrise and sunset in September in Saint Louis?
How many hours of sunshine does Saint Louis have in September?
What is the UV index reading in September in Saint Louis?
Average temperature in September
Saint Louis, VA
- Average high temperature in September: 77.4°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (38.7°F).
- Average low temperature in September: 58.3°F
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (24.8°F).
Average pressure in September
Saint Louis, VA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Saint Louis, VA
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is March (7.3mph).
The calmest month (with the lowest average wind speed) is August (4.4mph).
Average humidity in September
Saint Louis, VA
- Average humidity in September: 77%
The months with the highest relative humidity are October and December (78%).
The month with the lowest relative humidity is July (73%).
Average rainfall in September
Saint Louis, VA
- Average rainfall in September: 1.93"
The wettest months (with the highest rainfall) are May and August (3.35").
The driest month (with the least rainfall) is September (1.93").
Average rainfall days in September
Saint Louis, VA
- Average rainfall days in September: 13.7 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (10.1 days).
Average snowfall in September
Saint Louis, VA
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.17").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Saint Louis, VA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.8 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
Saint Louis, VA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are January and December (Average sunshine: 5h and 6min).
Average sunshine days in September
Saint Louis, VA
- Average sunshine days in September: 14.7 days
The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is May (11.1 days).
Average UV index in September
Saint Louis, VA
- Average UV index in September: 4
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, November and December (UV index 2).
Average cloud cover in September
Saint Louis, VA
- Average cloud cover in September: 36
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Saint Louis, VA
- Average visibility in September: 5mi
The months with the highest visibility are February, March, April, June, July, August and November (6mi).
The months with the lowest visibility are January, May, September, October and December (5mi).
Saint Louis, Virginia, USA
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