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 average high-temperature shows a slight dip in September, from August's 85.3°F (29.6°C) to a still moderately hot 79.5°F (26.4°C). September brings with it a nighttime average temperature of 59.7°F (15.4°C).Humidity
In September, the average relative humidity is 73%.Rainfall
In Saint Peters, in September, during 11.5 rainfall days, 1.34" (34mm) of precipitation is typically accumulated. Throughout the year, in Saint Peters, Missouri, there are 133.4 rainfall days, and 20.98" (533mm) of precipitation is accumulated.Snowfall
In Saint Peters, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:32 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:46 pm CDT.
Sunshine
The average sunshine in September is 9.6h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum daily UV index of 5 during September morphs into the following directions:
Undertake protective steps - Preventing sun damage is advised. To guard against the harmful effects of the Sun, minimize exposure during midday. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
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 much does it rain in September?
When it does not snow?
What is the average length of the day in September in Saint Peters?
When are sunrise and sunset in September?
How many hours of sunshine does Saint Peters have in September?
What is the UV index intensity in September?
Average temperature in September
Saint Peters, MO
- Average high temperature in September: 79.5°F
The warmest month (with the highest average high temperature) is July (87.1°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in September: 59.7°F
The month with the highest average low temperature is July (68.4°F).
The coldest month (with the lowest average low temperature) is January (23.9°F).
Average pressure in September
Saint Peters, 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
Saint Peters, MO
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).
Average humidity in September
Saint Peters, 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
Saint Peters, MO
- Average rainfall in September: 1.34"
The wettest month (with the highest rainfall) is April (2.48").
The driest month (with the least rainfall) is February (1.06").
Average rainfall days in September
Saint Peters, MO
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is February (6.7 days).
Average snowfall in September
Saint Peters, MO
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.65").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Saint Peters, MO
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (5.8 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 Peters, 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 4min
The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in September
Saint Peters, MO
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is January (20.4 days).
The month with the least sunshine days is July (12.7 days).
Average UV index in September
Saint Peters, 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, November and December (UV index 2).
Average cloud cover in September
Saint Peters, MO
- Average cloud cover in September: 28
The month with the most cloud cover is January (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Saint Peters, 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).
Saint Peters, Missouri, USA
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