September weather forecastBrook Mount, IA
September
Weather in September
September, the first month of the autumn in Brook Mount, is still a warm month, with an average temperature ranging between min 55.8°F (13.2°C) and max 74.1°F (23.4°C).Temperature
September brings a slight decrease in temperature, down from a warm 79.5°F (26.4°C) in August to a still moderately hot 74.1°F (23.4°C). Throughout the month of September, Brook Mount reports a steady low-temperature average of 55.8°F (13.2°C).Humidity
In September, the average relative humidity is 74%.Rainfall
In Brook Mount, in September, during 8.8 rainfall days, 1.02" (26mm) of precipitation is typically accumulated. In Brook Mount, during the entire year, the rain falls for 97 days and collects up to 10.12" (257mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:47 am and sunset at 7:54 pm. On the last day of September, sunrise is at 7:17 am and sunset at 7:03 pm CDT.
Sunshine
In September, the average sunshine is 9h.UV index
In Brook Mount, Iowa, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 4 translates into these guidelines:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. The Sun's radiation is especially intense around midday; try to stay in shade during this period. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Brook Mount, IA
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (25.5°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (13.3°F).
Average pressure in September
Brook Mount, IA
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Brook Mount, IA
- Average wind speed in September: 8.8mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.5mph).
Average humidity in September
Brook Mount, IA
- Average humidity in September: 74%
The month with the highest relative humidity is January (84%).
The months with the lowest relative humidity are April and October (67%).
Average rainfall in September
Brook Mount, IA
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is May (1.57").
The driest month (with the least rainfall) is January (0.24").
Average rainfall days in September
Brook Mount, IA
- Average rainfall days in September: 8.8 days
The month with the highest number of rainy days is May (13.8 days).
The months with the least rainy days are January and February (2.3 days).
Average snowfall in September
Brook Mount, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.26").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Brook Mount, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.7 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
Brook Mount, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Brook Mount, IA
- Average sunshine days in September: 19 days
The month with the most sunshine days is November (23 days).
The month with the least sunshine days is May (14.2 days).
Average UV index in September
Brook Mount, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and February (UV index 1).
Average cloud cover in September
Brook Mount, IA
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility in September
Brook Mount, IA
- 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).





