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
As August makes way for September, Ballwin's average high-temperature eases from a tropical 86.5°F (30.3°C) to a moderately hot 80.1°F (26.7°C). September witnesses an average nighttime temperature of 59.9°F (15.5°C) in Ballwin.Humidity
In September, the average relative humidity in Ballwin, Missouri, is 73%.Rainfall
In Ballwin, in September, during 11.6 rainfall days, 1.73" (44mm) of precipitation is typically accumulated. Throughout the year, in Ballwin, there are 134.1 rainfall days, and 23.82" (605mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
In September, the average length of the day in Ballwin is 12h and 25min.On the first day of September, sunrise is at 6:32 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:46 pm CDT.
Sunshine
The average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index in Ballwin, Missouri, is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: In September, the maximum UV index of 5 suggests this advice:
Act with care - The suggestion to avoid sunburn is emphasized. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature in Ballwin?
What is the average humidity in September in Ballwin?
How many days does it rain in September in Ballwin?
When it does not snow in Ballwin?
How many hours of daylight does Ballwin have in September?
What time are sunrise and sunset in September in Ballwin?
How long on average sun shines in September in Ballwin?
What is the UV index reading in September in Ballwin?
Average temperature in September
Ballwin, MO
- Average high temperature in September: 80.1°F
The warmest month (with the highest average high temperature) is July (88.2°F).
The month with the lowest average high temperature is January (38.5°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 (24.6°F).
Average pressure in September
Ballwin, 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
Ballwin, MO
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is January (8.8mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).
Average humidity in September
Ballwin, 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
Ballwin, MO
- Average rainfall in September: 1.73"
The wettest month (with the highest rainfall) is May (3.03").
The driest month (with the least rainfall) is February (1.1").
Average rainfall days in September
Ballwin, MO
- Average rainfall days in September: 11.6 days
The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is December (6.1 days).
Average snowfall in September
Ballwin, MO
- Average snowfall in September: 0"
The month with the highest snowfall is December (1.3").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Ballwin, MO
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (6.4 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Ballwin, 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 July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in September
Ballwin, MO
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is December (20.3 days).
The month with the least sunshine days is May (12.6 days).
Average UV index in September
Ballwin, 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 and December (UV index 2).
Average cloud cover in September
Ballwin, 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
Ballwin, 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).
Ballwin, Missouri, USA
Weather forecast for your location
2. Allow the app to use your location