September weather forecastPrinceton Junction, NJ
September
Weather in September
September, the first month of the autumn in Princeton Junction, is also a moderately hot month, with temperature in the range of an average high of 75.7°F (24.3°C) and an average low of 59°F (15°C).Temperature
The beginning of September brings a slight decrease in the average high-temperature, transitioning from a moderately hot 82.9°F (28.3°C) in August to a still warm 75.7°F (24.3°C). Princeton Junction's average low-temperature for the month of September records at a refreshing 59°F (15°C).Humidity
In September, the average relative humidity is 77%.Rainfall
The month with the least rainfall is September, when the rain falls for 10 days and typically collects 0.67" (17mm) of precipitation.Snowfall
In Princeton Junction, snow does not fall in June through October.Daylight
In Princeton Junction, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:26 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:41 pm EDT.
Sunshine
In Princeton Junction, the average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index in Princeton Junction is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: The UV index of 4 during September translates into the following guidance:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Princeton Junction, NJ
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (36.9°F).
- Average low temperature in September: 59°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Princeton Junction, NJ
- Average pressure in September: 30.05"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
Princeton Junction, NJ
- Average wind speed in September: 6mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in September
Princeton Junction, NJ
- Average humidity in September: 77%
The month with the highest relative humidity is October (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Princeton Junction, NJ
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is July (1.69").
The driest month (with the least rainfall) is September (0.67").
Average rainfall days in September
Princeton Junction, NJ
- Average rainfall days in September: 10 days
The month with the highest number of rainy days is July (13.9 days).
The month with the least rainy days is January (6.1 days).
Average snowfall in September
Princeton Junction, NJ
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.42").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Princeton Junction, NJ
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.6 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Princeton Junction, NJ
- Average daylight in September: 12h and 24min
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 24min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in September
Princeton Junction, NJ
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is January (21.8 days).
The month with the least sunshine days is July (13.3 days).
Average UV index in September
Princeton Junction, 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
Princeton Junction, NJ
- Average cloud cover in September: 38
The months with the most cloud cover are February, March and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility in September
Princeton Junction, NJ
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
