September weather forecastAnnandale, NJ
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Annandale, New Jersey, with an average temperature fluctuating between 56.1°F (13.4°C) and 74.7°F (23.7°C).Temperature
September ushers in a minor alteration in Annandale's climate, with the average high-temperature moving from August's 81.9°F (27.7°C) to a still warm 74.7°F (23.7°C). Annandale experiences an average low-temperature of 56.1°F (13.4°C) in month of September.Humidity
The average relative humidity in September is 78%.Rainfall
The month with the least rainfall is September, when the rain falls for 12.3 days and typically collects 1.89" (48mm) of precipitation.Snowfall
June through September are months without snowfall in Annandale.Daylight
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 7:31 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:42 pm EDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
In Annandale, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: In September, the maximum UV index of 4 translates into these guidelines:
Exercise prevention - Protecting skin and eyes from harm is required. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Annandale, NJ
- Average high temperature in September: 74.7°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (35.1°F).
- Average low temperature in September: 56.1°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (22.3°F).
Average pressure in September
Annandale, 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
Annandale, NJ
- Average wind speed in September: 5.6mph
The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in September
Annandale, NJ
- Average humidity in September: 78%
The months with the highest relative humidity are February, October and December (80%).
The month with the lowest relative humidity is April (75%).
Average rainfall in September
Annandale, NJ
- Average rainfall in September: 1.89"
The wettest month (with the highest rainfall) is December (3.35").
The driest month (with the least rainfall) is September (1.89").
Average rainfall days in September
Annandale, NJ
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is January (8.8 days).
Average snowfall in September
Annandale, NJ
- Average snowfall in September: 0"
The month with the highest snowfall is March (4.76").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Annandale, NJ
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (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
Annandale, NJ
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 0min).
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 24min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Annandale, NJ
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is November (17.5 days).
The month with the least sunshine days is June (11 days).
Average UV index in September
Annandale, NJ
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Annandale, NJ
- Average cloud cover in September: 39
The months with the most cloud cover are February and December (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 34).
Average visibility in September
Annandale, NJ
- Average visibility in September: 5mi
The months with the highest visibility are January, March, April, June, July, November and December (6mi).
The months with the lowest visibility are February, May, August, September and October (5mi).





