September weather forecastThornapple, WI
September
Weather in September
September, the first month of the autumn in Thornapple, is also an agreeable month, with an average temperature varying between 68.9°F (20.5°C) and 49.1°F (9.5°C).Temperature
The arrival of September corresponds with a minor reduction in the average high-temperature, down from August's warm 76.8°F (24.9°C) to an agreeable 68.9°F (20.5°C). Throughout September, an average nighttime temperature of 49.1°F (9.5°C) is experienced.Humidity
In Thornapple, the average relative humidity in September is 80%.Rainfall
In Thornapple, in September, during 12.2 rainfall days, 1.61" (41mm) of precipitation is typically accumulated. Throughout the year, there are 128.5 rainfall days, and 23.94" (608mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 31min.On the first day of September, sunrise is at 6:27 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:46 pm CDT.
Sunshine
The average sunshine in September in Thornapple is 8.1h.UV index
In September, the average daily maximum UV index in Thornapple is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Thornapple, WI
- Average high temperature in September: 68.9°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The month with the lowest average high temperature is January (18.1°F).
- Average low temperature in September: 49.1°F
The month with the highest average low temperature is July (58.5°F).
The coldest month (with the lowest average low temperature) is January (5.4°F).
Average pressure in September
Thornapple, WI
- Average pressure in September: 30.01"Hg
The months with the highest atmospheric pressure are January and February (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Thornapple, WI
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (8.8mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in September
Thornapple, WI
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (92%).
The month with the lowest relative humidity is May (75%).
Average rainfall in September
Thornapple, WI
- Average rainfall in September: 1.61"
The wettest month (with the highest rainfall) is June (3.43").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in September
Thornapple, WI
- Average rainfall days in September: 12.2 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is February (2.9 days).
Average snowfall in September
Thornapple, WI
- Average snowfall in September: 0"
The month with the highest snowfall is December (7.28").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Thornapple, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (19.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Thornapple, WI
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 8h and 6min
The month with the most sunshine is July (Average sunshine: 9h and 36min).
The months with the least sunshine are January and February (Average sunshine: 2h and 36min).
Average sunshine days in September
Thornapple, WI
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is October (16 days).
The months with the least sunshine days are February and April (10 days).
Average UV index in September
Thornapple, WI
- 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, February and December (UV index 1).
Average cloud cover in September
Thornapple, WI
- Average cloud cover in September: 40
The months with the most cloud cover are January and February (Cloud cover 75).
The months with the least cloud cover are July and August (Cloud cover 38).
Average visibility in September
Thornapple, WI
- Average visibility in September: 5mi
The months with the highest visibility are May and June (6mi).
The months with the lowest visibility are January, February and December (4mi).
