September weather forecast
Old Tappan, NJ

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Weather in September

September, the first month of the autumn in Old Tappan, is still a warm month, with an average temperature ranging between max 75.4°F (24.1°C) and min 59.9°F (15.5°C).

Temperature

September witnesses a gentle descent in average high-temperature, descending from August's moderately hot 82.9°F (28.3°C) to a still warm 75.4°F (24.1°C). September nights are marked by an average low-temperature of 59.9°F (15.5°C).

Humidity

In Old Tappan, the average relative humidity in September is 73%.

Rainfall

The month with the least rainfall is September, when the rain falls for 11.6 days and typically collects 1.73" (44mm) of precipitation.

Snowfall

May through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of the month, sunrise is at 6:23 am and sunset at 7:28 pm. On the last day of September, sunrise is at 6:52 am and sunset at 6:39 pm EDT.

Sunshine

In Old Tappan, New Jersey, the average sunshine in September is 8.6h.

UV index

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for average individuals.
Note: The daily maximum UV index of 4 in September interprets into the following advice:
Take necessary precautions - Defending against sun damage is advocated. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.

Frequently asked questions

What are the temperatures in September?

September temperatures vary between a high-temperature of 75.4°F (24.1°C) and a low-temperature of 59.9°F (15.5°C). In August, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, is estimated at 87.8°F (31°C).

What is the average humidity in September?

In Old Tappan, the average relative humidity in September is 73%.

What is the driest month?

The month with the least rainfall in Old Tappan is September, when the rain falls for 11.6 days and typically collects 1.73" (44mm) of precipitation.

How much does it rain in September?

In Old Tappan, during September, the rain falls for 11.6 days and regularly aggregates up to 1.73" (44mm) of precipitation.

When it does not snow in Old Tappan?

May through October are months without snowfall.

What is the average length of the day in September in Old Tappan?

In September, the average day length is 12h and 28min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:23 am and sunset at 7:28 pm. On the last day of the month, sunrise is at 6:52 am and sunset at 6:39 pm EDT.

How long on average sun shines in September?

In Old Tappan, the average sunshine duration in September is 8.6h.

What is the UV index reading in September in Old Tappan?

The average daily maximum UV index in September in Old Tappan is 4. A UV Index of 3 to 5 symbolizes a moderate health threat from unsafe 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
Old Tappan, NJ

Average temperature in September - Old Tappan, NJ
  • Average high temperature in September: 75.4°F

The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (35.4°F).

  • Average low temperature in September: 59.9°F

The month with the highest average low temperature is July (68°F).
The coldest month (with the lowest average low temperature) is January (24.1°F).

Average pressure in September
Old Tappan, NJ

Average pressure in September - Old Tappan, NJ
  • Average pressure in September: 30.06"Hg

The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Old Tappan, NJ

Average wind speed in September - Old Tappan, NJ
  • Average wind speed in September: 6.3mph

The windiest months (with the highest average wind speed) are January and March (8.5mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).

Average humidity in September
Old Tappan, NJ

Average humidity in September - Old Tappan, NJ
  • Average humidity in September: 73%

The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is August (68%).

Average rainfall in September
Old Tappan, NJ

Average rainfall in September - Old Tappan, NJ
  • Average rainfall in September: 1.73"

The wettest month (with the highest rainfall) is December (3.46").
The driest month (with the least rainfall) is September (1.73").

Average rainfall days in September
Old Tappan, NJ

Average rainfall days in September - Old Tappan, NJ
  • Average rainfall days in September: 11.6 days

The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is January (8.2 days).

Average snowfall in September
Old Tappan, NJ

Average snowfall in September - Old Tappan, NJ
  • Average snowfall in September: 0"

The month with the highest snowfall is March (3.07").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Old Tappan, NJ

Average snowfall days in September - Old Tappan, NJ
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Old Tappan, NJ

Average daylight in September / Average sunshine in September - Old Tappan, NJ
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in September: 8h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days in September
Old Tappan, NJ

Average sunshine days in September - Old Tappan, NJ
  • Average sunshine days in September: 16.7 days

The months with the most sunshine days are January and November (18.1 days).
The months with the least sunshine days are April and June (12.7 days).

Average UV index in September
Old Tappan, NJ

Average UV index in September - Old Tappan, 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
Old Tappan, NJ

Average cloud cover in September - Old Tappan, NJ
  • Average cloud cover in September: 37

The months with the most cloud cover are February, March and December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in September
Old Tappan, NJ

Average visibility in September - Old Tappan, NJ
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Old Tappan, New Jersey, USA

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