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's arrival signals a moderate reduction in the average high-temperature, easing from 82.4°F (28°C) in August to a still moderately hot 76.6°F (24.8°C). In the month of September, the temperature in Clayton generally rests at an average low of 61.9°F (16.6°C).Humidity
The average relative humidity in September is 78%.Rainfall
In September, the rain falls for 14.3 days. Throughout September, 2.32" (59mm) of precipitation is accumulated. Throughout the year, there are 169.2 rainfall days, and 34.96" (888mm) of precipitation is accumulated.Snowfall
In Clayton, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:46 pm EDT.
Sunshine
In September, the average sunshine is 9.4h.UV index
In Clayton, Delaware, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 suggests this advice:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. 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
What is the temperature in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September in Clayton?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Clayton, DE
- Average high temperature in September: 76.6°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (39.2°F).
- Average low temperature in September: 61.9°F
The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (27.9°F).
Average pressure in September
Clayton, DE
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Clayton, DE
- Average wind speed in September: 6.7mph
The windiest months (with the highest average wind speed) are February and March (9.5mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in September
Clayton, DE
- Average humidity in September: 78%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Clayton, DE
- Average rainfall in September: 2.32"
The wettest month (with the highest rainfall) is August (3.86").
The driest month (with the least rainfall) is January (2.13").
Average rainfall days in September
Clayton, DE
- Average rainfall days in September: 14.3 days
The month with the highest number of rainy days is July (19 days).
The month with the least rainy days is November (9.3 days).
Average snowfall in September
Clayton, DE
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Clayton, DE
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Clayton, DE
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in September
Clayton, DE
- Average sunshine days in September: 13.4 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (9.5 days).
Average UV index in September
Clayton, DE
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in September
Clayton, DE
- Average cloud cover in September: 33
The months with the most cloud cover are February and March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in September
Clayton, DE
- 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).
Clayton, Delaware, USA
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