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 is marked by a minor decrease in temperature, transitioning from a tropical 92.5°F (33.6°C) in August to a warm 84.4°F (29.1°C). Saint Louis observes an average low-temperature of 64.9°F (18.3°C) during September.Heat index
The heat index for September is appraised at a hot 91.4°F (33°C). Implement enhanced safety actions, heat cramps and heat exhaustion could occur. Sustained activity might result in heatstroke.Metrics for the heat index primarily focus on shaded spots and light wind conditions. Direct sunlight has the potential to heighten heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is achieved by amalgamating air temperature with the relative humidity readings. The individual's temperature perception can be influenced by numerous factors such as metabolic variations, physical activity, and clothing. One must note that being under the direct sun can escalate the heat's effects, with the heat index possibly rising by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Young individuals are generally in more danger than adults due to their lower capacity to sweat. Moreover, their large skin surface in relation to their small bodies and the increased heat generation from their activities makes them more vulnerable.
Humidity
The average relative humidity in September in Saint Louis is 68%.Rainfall
In Saint Louis, during September, the rain falls for 11.8 days and regularly aggregates up to 1.65" (42mm) of precipitation. Throughout the year, there are 111.2 rainfall days, and 17.13" (435mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall.Daylight
In Saint Louis, the average length of the day in September is 12h and 23min.On the first day of the month, sunrise is at 7:00 am and sunset at 7:53 pm. On the last day of September, sunrise is at 7:22 am and sunset at 7:12 pm CDT.
Sunshine
In September, the average sunshine is 8.5h.UV index
In Saint Louis, 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 radiation for ordinary individuals.Note: The daily high UV index of 5 in September translates into this advice:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it 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 Saint Louis have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Saint Louis have in September?
What is the UV index intensity in September?
Average temperature in September
Saint Louis, OK
- Average high temperature in September: 84.4°F
The warmest month (with the highest average high temperature) is August (92.5°F).
The month with the lowest average high temperature is January (49.3°F).
- Average low temperature in September: 64.9°F
The month with the highest average low temperature is July (72.7°F).
The coldest month (with the lowest average low temperature) is January (33.4°F).
Average pressure in September
Saint Louis, OK
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Saint Louis, OK
- Average wind speed in September: 7.8mph
The windiest months (with the highest average wind speed) are March and April (11.1mph).
The calmest months (with the lowest average wind speed) are July and August (7.5mph).
Average humidity in September
Saint Louis, OK
- Average humidity in September: 68%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is August (63%).
Average rainfall in September
Saint Louis, OK
- Average rainfall in September: 1.65"
The wettest month (with the highest rainfall) is May (2.6").
The driest month (with the least rainfall) is February (0.71").
Average rainfall days in September
Saint Louis, OK
- Average rainfall days in September: 11.8 days
The month with the highest number of rainy days is May (12.4 days).
The month with the least rainy days is January (5.3 days).
Average snowfall in September
Saint Louis, OK
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.75").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Saint Louis, OK
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Saint Louis, OK
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 8h and 3min
The month with the most sunshine is August (Average sunshine: 11h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
Saint Louis, OK
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is January (24 days).
The months with the least sunshine days are April, May and September (15.9 days).
Average UV index in September
Saint Louis, OK
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 2).
Average cloud cover in September
Saint Louis, OK
- Average cloud cover in September: 28
The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is August (Cloud cover 20).
Average visibility in September
Saint Louis, OK
- 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).
Saint Louis, Oklahoma, USA
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