September weather forecastGarnavillo, IA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Garnavillo, Iowa, with an average temperature varying between 52.7°F (11.5°C) and 71.8°F (22.1°C).Temperature
In September, the average high-temperature marginally decreases from a warm 77.7°F (25.4°C) in August to an agreeable 71.8°F (22.1°C). September brings an average low-temperature of 52.7°F (11.5°C) to Garnavillo.Humidity
The average relative humidity in September is 80%.Rainfall
In Garnavillo, in September, it is raining for 11.5 days, with typically 2.6" (66mm) of accumulated precipitation. In Garnavillo, Iowa, during the entire year, the rain falls for 138 days and collects up to 29.21" (742mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:30 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:47 pm CDT.
Sunshine
In Garnavillo, the average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Garnavillo, IA
- Average high temperature in September: 71.8°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (23.5°F).
- Average low temperature in September: 52.7°F
The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is January (10.9°F).
Average pressure in September
Garnavillo, 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 (29.89"Hg).
Average wind speed in September
Garnavillo, IA
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Garnavillo, IA
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (88%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
Garnavillo, IA
- Average rainfall in September: 2.6"
The wettest month (with the highest rainfall) is June (4.25").
The driest month (with the least rainfall) is January (1.1").
Average rainfall days in September
Garnavillo, IA
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is February (3.6 days).
Average snowfall in September
Garnavillo, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.04").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Garnavillo, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Garnavillo, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
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 August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Garnavillo, IA
- Average sunshine days in September: 15.8 days
The month with the most sunshine days is November (18.6 days).
The month with the least sunshine days is June (8.9 days).
Average UV index in September
Garnavillo, IA
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Garnavillo, IA
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Garnavillo, IA
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, February, July and August (5mi).
