September weather forecastDelaware, NJ
September
Weather in September
September, the first month of the autumn in Delaware, is still a warm month, with an average temperature ranging between min 53.2°F (11.8°C) and max 73.4°F (23°C).Temperature
Delaware's progression into September involves a minor drop in the average high-temperature, slightly receding from 80.2°F (26.8°C) in August to a still moderately hot 73.4°F (23°C). Throughout September, the temperature falls to an average low of 53.2°F (11.8°C).Humidity
In September, the average relative humidity in Delaware is 79%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.5 days and typically collects 1.81" (46mm) of precipitation.Snowfall
June through September are months without snowfall in Delaware.Daylight
In Delaware, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:27 am and sunset at 7:32 pm. On the last day of September, in Delaware, sunrise is at 6:56 am and sunset at 6:43 pm EDT.
Sunshine
In Delaware, New Jersey, the average sunshine in September is 8.7h.UV index
In Delaware, New Jersey, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In September, a regular UV index of 4 translates into these guidelines:
Take necessary precautions - Protection from skin and eye injury is mandatory. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Delaware, NJ
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in September: 53.2°F
The month with the highest average low temperature is July (61.2°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in September
Delaware, NJ
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Delaware, NJ
- Average wind speed in September: 5.4mph
The windiest months (with the highest average wind speed) are January, February and March (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in September
Delaware, NJ
- Average humidity in September: 79%
The months with the highest relative humidity are February, October and December (82%).
The month with the lowest relative humidity is April (76%).
Average rainfall in September
Delaware, NJ
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is July (3.11").
The driest month (with the least rainfall) is September (1.81").
Average rainfall days in September
Delaware, NJ
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is July (17.4 days).
The month with the least rainy days is February (9.5 days).
Average snowfall in September
Delaware, NJ
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.67").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Delaware, NJ
- 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
Delaware, NJ
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).
Average sunshine days in September
Delaware, NJ
- Average sunshine days in September: 15.6 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is June (11.1 days).
Average UV index in September
Delaware, NJ
- Average UV index in September: 4
The month with the highest UV index is June (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Delaware, NJ
- Average cloud cover in September: 40
The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 35).
Average visibility in September
Delaware, NJ
- Average visibility in September: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).
