September weather forecastBrentwood, MO
September
Weather in September
September, the first month of the autumn in Brentwood, is still a warm month, with an average temperature fluctuating between 79.7°F (26.5°C) and 60.1°F (15.6°C).Temperature
A subtle shift in Brentwood's weather is observed as August turns into September, with the average high temperature reducing from 85.5°F (29.7°C) to a still warm 79.7°F (26.5°C). In the month of September, Brentwood records a consistent average low-temperature of 60.1°F (15.6°C).Humidity
In September, the average relative humidity in Brentwood is 73%.Rainfall
In Brentwood, during September, the rain falls for 12 days and regularly aggregates up to 1.97" (50mm) of precipitation. In Brentwood, Missouri, during the entire year, the rain falls for 144.8 days and collects up to 30.59" (777mm) of precipitation.Snowfall
In Brentwood, snow does not fall in April through October.Daylight
In September, the average length of the day is 12h and 25min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:31 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:45 pm CDT.
Sunshine
In Brentwood, the average sunshine in September is 9.6h.UV index
In Brentwood, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for the average person.Note: A maximum daily UV index of 5 during September morphs into the following directions:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. To protect against the Sun's most potent rays, avoid direct exposure around midday. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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
Brentwood, 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).
