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
A mild shift in the average high-temperature occurs in September, reducing from a warm 75.4°F (24.1°C) in August to a pleasant 68.9°F (20.5°C). The average nighttime temperature in Grafton lowers to a moderate 55.9°F (13.3°C) throughout September.Humidity
In Grafton, the average relative humidity in September is 79%.Rainfall
In Grafton, Wisconsin, in September, during 12.9 rainfall days, 2.17" (55mm) of precipitation is typically accumulated. Throughout the year, there are 134.9 rainfall days, and 23.94" (608mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In Grafton, Wisconsin, the average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:16 am and sunset at 7:26 pm. On the last day of September, in Grafton, Wisconsin, sunrise is at 6:48 am and sunset at 6:34 pm CDT.
Sunshine
In September, the average sunshine in Grafton is 9.1h.UV index
The average daily maximum UV index in September in Grafton is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum UV index of 4 in September translates into the following recommendations:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Frequently asked questions
What is the average September temperature in Grafton?
What is the average humidity in September in Grafton?
How much does it rain in Grafton in September?
When it does not snow in Grafton?
Does it snow in Grafton in September?
What is the average length of the day in September in Grafton?
When are sunrise and sunset in September in Grafton?
How long on average sun shines in September in Grafton?
How high is the UV index in September in Grafton?
Average temperature in September
Grafton, WI
- Average high temperature in September: 68.9°F
The warmest month (with the highest average high temperature) is July (76.1°F).
The month with the lowest average high temperature is January (25.5°F).
- Average low temperature in September: 55.9°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (15.8°F).
Average pressure in September
Grafton, WI
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January, February and March (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Grafton, WI
- Average wind speed in September: 8.9mph
The windiest month (with the highest average wind speed) is January (12.1mph).
The calmest month (with the lowest average wind speed) is July (7.5mph).
Average humidity in September
Grafton, WI
- Average humidity in September: 79%
The month with the highest relative humidity is January (86%).
The months with the lowest relative humidity are April, October and November (77%).
Average rainfall in September
Grafton, WI
- Average rainfall in September: 2.17"
The wettest month (with the highest rainfall) is July (2.99").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in September
Grafton, WI
- Average rainfall days in September: 12.9 days
The month with the highest number of rainy days is May (15.8 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in September
Grafton, WI
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.43").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Grafton, WI
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Grafton, WI
- Average daylight in September: 12h and 3min
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 0min).
- Average sunshine in September: 9h and 1min
The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in September
Grafton, WI
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is December (16.4 days).
The month with the least sunshine days is July (11.6 days).
Average UV index in September
Grafton, WI
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Grafton, WI
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 63).
The months with the least cloud cover are July and August (Cloud cover 28).
Average visibility in September
Grafton, WI
- 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).
Grafton, Wisconsin, USA
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