September weather forecastTrenton, NJ
September
Weather in September
September ushers in autumn and bids goodbye to the hot summer weather. Although temperatures decrease, the city stays warm and pleasant. Rainfall lowers to 2.01in, bringing a refreshing change to the preceding humid months. The football season kickoff draws Trenton's crowds, reveling in the comfortable weather conditions. As daylight decreases, the city experiences a slow, scenic transition from summer heat to autumn cool.Temperature
September is marked by a subtle drop in average high-temperatures, transitioning from a warm 82.9°F (28.3°C) in August to a still moderately hot 76.1°F (24.5°C). In September, the average low-temperature records at a refreshing 59.4°F (15.2°C) during the nights.Humidity
In September, the average relative humidity is 76%.Rainfall
In Trenton, in September, it is raining for 13.2 days, with typically 2.01" (51mm) of accumulated precipitation. Throughout the year, in Trenton, New Jersey, there are 156.8 rainfall days, and 31.81" (808mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Trenton, New Jersey, 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 7:30 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 8.8h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: The daily high UV index of 4 during September translates into the following recommendations:
Make use of precautions - It is urged to ward off sun damage. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Trenton, NJ
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (85.1°F).
The month with the lowest average high temperature is January (36.9°F).
- Average low temperature in September: 59.4°F
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (24.8°F).
Average pressure in September
Trenton, 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
Trenton, NJ
- Average wind speed in September: 5.9mph
The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in September
Trenton, NJ
- Average humidity in September: 76%
The months with the highest relative humidity are February and October (78%).
The month with the lowest relative humidity is April (72%).
Average rainfall in September
Trenton, NJ
- Average rainfall in September: 2.01"
The wettest month (with the highest rainfall) is July (3.74").
The driest month (with the least rainfall) is January (1.85").
Average rainfall days in September
Trenton, NJ
- Average rainfall days in September: 13.2 days
The month with the highest number of rainy days is July (18.5 days).
The month with the least rainy days is January (7.9 days).
Average snowfall in September
Trenton, NJ
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.72").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Trenton, NJ
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Trenton, 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 36min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in September
Trenton, NJ
- Average sunshine days in September: 14 days
The month with the most sunshine days is November (20.6 days).
The month with the least sunshine days is July (9.3 days).
Average UV index in September
Trenton, NJ
- Average UV index in September: 4
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, February, March, November and December (UV index 2).
Average cloud cover in September
Trenton, NJ
- Average cloud cover in September: 37
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 32).
Average visibility in September
Trenton, 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).
