Trenton
New Jersey, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Trenton, NJ

A full aerial view of Trenton, New Jersey, with the George Washington statue
A full aerial view of Trenton, New Jersey, with the George Washington statue
The first month of the autumn, September, is also a moderately hot month in Trenton, New Jersey, with temperature in the range of an average low of 59.4°F (15.2°C) and an average high of 76.1°F (24.5°C).

Temperature

In September, the average high-temperature marginally drops, from a moderately hot 82.9°F (28.3°C) in August, to a still warm 76.1°F (24.5°C). In September, the average low-temperature is 59.4°F (15.2°C).

Humidity

In Trenton, the average relative humidity in September is 76%.

Rainfall

In Trenton, in September, it is raining for 13.2 days, with typically 2.01" (51mm) of accumulated precipitation. In Trenton, during the entire year, the rain falls for 156.8 days and collects up to 31.81" (808mm) of precipitation.

Snowfall

June through September are months without snowfall.

Daylight

The average length of the day in September is 12.4h.

Sunshine

The average sunshine in Trenton is 8.8h.

UV index

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to the UV radiation for average individuals.
Note: The average daily UV index of 4 in September transform into the following instructions:
Take precautions - Protection against sun damage is advised. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in September in Trenton?

In September, in Trenton, the average high-temperature is 76.1°F (24.5°C), and the average low-temperature is 59.4°F (15.2°C).

What is the average humidity in September in Trenton?

The average relative humidity in September in Trenton is 76%.

How much does it rain in Trenton in September?

In September, in Trenton, the rain falls for 13.2 days. Throughout September, 2.01" (51mm) of precipitation is accumulated.

Does it snow in Trenton in September?

In Trenton, New Jersey, in September, it doesn't snow. In October, it regularly snows.

When it does not snow in Trenton?

June through September are months without snowfall in Trenton, New Jersey.

How many hours of daylight does Trenton have in September?

The average length of the day in September is 12.4h.

How long on average sun shines in September in Trenton?

In September, the average sunshine in Trenton is 8.8h.

How high is the UV index in September in Trenton?

In Trenton, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health risk from the exposure to the Sun's UV rays.
Average temperature in September - Trenton, NJ
  • Average high temperature in September: 24.5°C

The warmest month (with the highest average high temperature) is July (29.5°C).
The month with the lowest average high temperature is January (2.7°C).

  • Average low temperature in September: 15.2°C

The month with the highest average low temperature is July (19.6°C).
The coldest month (with the lowest average low temperature) is January (-4°C).

Average humidity in September - Trenton, NJ
  • Average humidity in September: 76%

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: 51mm

The wettest month (with the highest rainfall) is July (95mm).
The driest month (with the lowest rainfall) is January (47mm).

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 lowest number of rainy days is January (7.9 days).

Average snowfall in September - Trenton, NJ
  • Average snowfall in September: 0mm

The month with the highest snowfall is March (69mm).
Months with the lowest snowfall are June, July, August and September (0mm).

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).
Months with the lowest number of snowfall days are June, July, August and September (0 days).

Average daylight in September / Average sunshine in September - Trenton, NJ
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 15h).
The month with shortest days is December (Average daylight: 9.4h).

  • Average sunshine in September: 8.8h

The month with most sunshine is July (Average sunshine: 10.6h).
The month with least sunshine is February (Average sunshine: 4.8h).

Average UV index in September - Trenton, NJ
  • Average UV index in September: 4

Months with the highest UV index are May, June, July and August (UV index 6).
Months with the lowest UV index are January, February, March, November and December (UV index 2).