September weather forecastKirkwood, MO
September
Weather in September
September transitions Kirkwood's weather from the intense heat of summer towards milder fall conditions. Compared to August, the temperatures experience a definitive descent, though still maintaining a moderately warm atmosphere. A decrease in rainfall is also observed, lending the city a drier condition. These milder temperatures and changing leaf colors mark the beginning of fall, making the city visually stunning. As September gives way to October, cooler temperatures become more pronounced, ushering in the heart of the fall season.Temperature
The start of September involves a subtle temperature drop, shifting from a moderately hot 85.5°F (29.7°C) in August to a still warm 79.7°F (26.5°C). Kirkwood throughout September, records an average low-temperature of 60.1°F (15.6°C).Humidity
In Kirkwood, the average relative humidity in September is 73%.Rainfall
In Kirkwood, in September, during 12 rainfall days, 1.97" (50mm) of precipitation is typically accumulated. In Kirkwood, during the entire year, the rain falls for 144.8 days and collects up to 30.59" (777mm) of precipitation.Snowfall
In Kirkwood, snow does not fall in April through October.Daylight
In September, the average length of the day in Kirkwood is 12h and 25min.On the first day of September in Kirkwood, sunrise is at 6:31 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:45 pm CDT.
Sunshine
In September, the average sunshine is 9.6h.UV index
In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The maximum UV index, 5 during September, leads to the following recommendations:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Heed this! Snow reflection can almost augment the UV radiation of the sun by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Kirkwood, 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 (37.8°F).
- Average low temperature in September: 60.1°F
The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Kirkwood, 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
Kirkwood, MO
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is January (9.2mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in September
Kirkwood, 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 (70%).
Average rainfall in September
Kirkwood, MO
- Average rainfall in September: 1.97"
The wettest month (with the highest rainfall) is May (3.58").
The driest month (with the least rainfall) is February (1.69").
Average rainfall days in September
Kirkwood, MO
- Average rainfall days in September: 12 days
The month with the highest number of rainy days is May (16.9 days).
The month with the least rainy days is January (6.5 days).
Average snowfall in September
Kirkwood, 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
Kirkwood, MO
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is February (5.2 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Kirkwood, MO
- Average daylight in September: 12h and 24min
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 36min
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 36min).
Average sunshine days in September
Kirkwood, MO
- Average sunshine days in September: 15.2 days
The month with the most sunshine days is January (21 days).
The month with the least sunshine days is June (11.2 days).
Average UV index in September
Kirkwood, 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
Kirkwood, 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
Kirkwood, 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).





