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
September brings a slight decrease in the average high-temperature, shifting from 80.1°F (26.7°C) in August to a still moderately hot 74.1°F (23.4°C). During September, Grand Mound experiences an average low-temperature of 55°F (12.8°C) at night.Humidity
The average relative humidity in September is 77%.Rainfall
In September, in Grand Mound, the rain falls for 11.2 days. Throughout September, 2.28" (58mm) of precipitation is accumulated. In Grand Mound, during the entire year, the rain falls for 142.1 days and collects up to 28.35" (720mm) of precipitation.Snowfall
In Grand Mound, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:29 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:45 pm CDT.
Sunshine
In September, the average sunshine is 9.2h.UV index
The average daily maximum UV index in September is 4. 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: The maximum daily UV index of 4 in September converts into the following recommendations:
Put precautions into practice - Protective measures against sun-induced damage are advised. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Enhance your sun protection with tightly woven, yet airy clothing.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September in Grand Mound?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Grand Mound have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Grand Mound, IA
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is January (26.6°F).
- Average low temperature in September: 55°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (14.4°F).
Average pressure in September
Grand Mound, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Grand Mound, IA
- Average wind speed in September: 7.7mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in September
Grand Mound, IA
- Average humidity in September: 77%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
Grand Mound, IA
- Average rainfall in September: 2.28"
The wettest month (with the highest rainfall) is May (4.61").
The driest month (with the least rainfall) is February (1.26").
Average rainfall days in September
Grand Mound, IA
- Average rainfall days in September: 11.2 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is February (5.3 days).
Average snowfall in September
Grand Mound, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.2").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Grand Mound, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.5 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
Grand Mound, IA
- Average daylight in September: 12h and 3min
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 12min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Grand Mound, IA
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is May (10.7 days).
Average UV index in September
Grand Mound, IA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Grand Mound, IA
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Grand Mound, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).
Grand Mound, Iowa, USA
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