September weather forecast and climate
Somerville, NJ

The first month of the autumn, September, is also a moderately hot month in Somerville, New Jersey, with temperature in the range of an average high of 75.2°F (24°C) and an average low of 58.1°F (14.5°C).

Temperature

In Somerville, the average high-temperature slightly decreases, from 82.4°F (28°C) in August, to a still warm 75.2°F (24°C). In Somerville, the average low-temperature is 58.1°F (14.5°C).

Humidity

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

Rainfall

The month with the least rainfall is September when the rain falls for 12.3 days and typically collects 1.54" (39mm) of precipitation.

Snowfall

June through September are months without snowfall in Somerville.

Daylight

The average length of the day in Somerville, New Jersey, is 12.4h.

Sunshine

In September, the average sunshine is 8.6h.

UV index

The average daily maximum UV index in Somerville is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to the UV radiation for ordinary individuals.
Note: In September, the average maximum UV index of 4 translate into the following recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. 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 Somerville?

In September, in Somerville, the average high-temperature is 75.2°F (24°C), and the average low-temperature is 58.1°F (14.5°C).

What is the average humidity in September in Somerville?

In September, the average relative humidity is 76%.

How much does it rain in Somerville in September?

In Somerville, during September, the rain falls for 12.3 days and regularly aggregates up to 1.54" (39mm) of precipitation.

What is the driest month in Somerville?

The month with the least rainfall in Somerville is September when the rain falls for 12.3 days and typically collects 1.54" (39mm) of precipitation.

Does it snow in Somerville in September?

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

When it does not snow in Somerville?

In Somerville snow does not fall in June through September.

How many hours of daylight does Somerville have in September?

In Somerville, New Jersey, the average length of the day in September is 12.4h.

How many hours of sunshine does Somerville have in September?

In September, the average sunshine in Somerville is 8.6h.

What is the UV index intensity in September in Somerville?

In September, the average daily maximum UV index in Somerville is 4. A UV Index of 3 to 5 symbolizes a medium health risk from unprotected exposure to the UV radiation.
Average temperature in September - Somerville, NJ
  • Average high temperature in September: 24°C

The warmest month (with the highest average high temperature) is July (29°C).
The month with the lowest average high temperature is January (2°C).

  • Average low temperature in September: 14.5°C

The month with the highest average low temperature is July (18.9°C).
The coldest month (with the lowest average low temperature) is January (-4.9°C).

Average pressure in September - Somerville, NJ
  • Average pressure in September: 1017.8mbar

The month with the highest atmospheric pressure is November (1019.7mbar).
The month with the lowest atmospheric pressure is June (1013.7mbar).

Average wind speed in September - Somerville, NJ
  • Average wind speed in September: 9.4km/h

The windiest month (with the highest average wind speed) is March (13.9km/h).
The calmest month (with the lowest average wind speed) is August (8.6km/h).

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

Months with the highest relative humidity are February, October and December (79%).
The month with the lowest relative humidity is April (74%).

Average rainfall in September - Somerville, NJ
  • Average rainfall in September: 39mm

The wettest month (with the highest rainfall) is December (74mm).
The driest month (with the least rainfall) is September (39mm).

Average rainfall days in September - Somerville, NJ
  • Average rainfall days in September: 12.3 days

The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is February (9 days).

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

The month with the highest snowfall is March (72mm).
Months with the least snowfall are June, July, August and September (0mm).

Average snowfall days in September - Somerville, NJ
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.8 days).
Months with the least snowfall days are June, July, August and September (0 days).

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

The month with the longest days is June (Average daylight: 15h).
The month with the shortest days is December (Average daylight: 9.3h).

  • Average sunshine in September: 8.6h

The month with the most sunshine is July (Average sunshine: 10.4h).
The month with the least sunshine is February (Average sunshine: 4.6h).

Average sunshine days in September - Somerville, NJ
  • Average sunshine days in September: 15 days

The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is June (11.7 days).

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

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

Average cloud cover in September - Somerville, NJ
  • Average cloud cover in September: 40

Months with the most cloud cover are February and December (Cloud cover 49).
Months with the least cloud cover are July and August (Cloud cover 34).

Average visibility in September - Somerville, NJ
  • Average visibility in September: 8km

Months with the highest visibility are January, February, March, April, June, July, August, October, November and December (9km).
Months with the lowest visibility are May and September (8km).