September weather forecast
Trenton, NJ

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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

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

The onset of September brings a small shift in high-temperatures, falling from a warm 82.9°F (28.3°C) in August to a still moderately hot 76.1°F (24.5°C). The temperature in Trenton, New Jersey, lowers to an average of 59.4°F (15.2°C) during September nights.

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

In Trenton, snow does not fall in June through September.

Daylight

The average length of the day in September is 12h and 27min.
On the first day of September, sunrise is at 6:27 am and sunset at 7:30 pm. On the last day of the month, 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 in Trenton is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for ordinary individuals.
Note: In September, a regular UV index of 4 translates into these guidelines:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. Opt for tightly woven and loose clothing to enhance protection from the Sun.
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Frequently asked questions

What are the temperatures in Trenton in September?

The high-temperature, in September, in Trenton, is 76.1°F (24.5°C), while the low-temperature averages to 59.4°F (15.2°C). In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is calculated to be 89.6°F (32°C).

What is the average humidity in September in Trenton?

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

How much does it rain in Trenton in September?

In Trenton, during September, the rain falls for 13.2 days and regularly aggregates up to 2.01" (51mm) of precipitation.

When it does not snow in Trenton?

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

Does it snow in Trenton in September?

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

What is the average length of the day in September in Trenton?

In Trenton, New Jersey, the average day length in September is 12h and 27min.

What time are sunrise and sunset in September in Trenton?

In September, on the first day of the month, sunrise is at 6:27 am and sunset at 7:30 pm. On the last day of the month, in Trenton, New Jersey, sunrise is at 6:55 am and sunset at 6:42 pm EDT.

How many hours of sunshine does Trenton have in September?

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

What is the UV index reading 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 exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Trenton, NJ

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).

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Average pressure in September
Trenton, NJ

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).

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Average wind speed in September
Trenton, NJ

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).

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Average humidity in September
Trenton, NJ

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%).

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Average rainfall in September
Trenton, NJ

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").

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Average rainfall days in September
Trenton, NJ

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).

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Average snowfall in September
Trenton, NJ

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").

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Average snowfall days in September
Trenton, NJ

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).

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Average daylight in September /
Average sunshine in September
Trenton, NJ

Average daylight in September / Average sunshine in September - Trenton, NJ
  • Average daylight in September: 12h and 2min

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 5min

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).

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Average sunshine days in September
Trenton, NJ

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).

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Average UV index in September
Trenton, NJ

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).

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Average cloud cover in September
Trenton, NJ

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).

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Average visibility in September
Trenton, NJ

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).

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Trenton, New Jersey, USA

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