September weather forecast
Mountain Lakes, NJ

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Weather in September

September, the first month of the autumn in Mountain Lakes, is still a warm month, with an average temperature varying between 56.3°F (13.5°C) and 74.3°F (23.5°C).

Temperature

As August transitions into September, Mountain Lakes sees a gentle drop in the average high-temperature, transitioning from a moderately hot 81.3°F (27.4°C) to a still warm 74.3°F (23.5°C). September's average low-temperature reading in Mountain Lakes, New Jersey, settles at a mild 56.3°F (13.5°C).

Humidity

The average relative humidity in September in Mountain Lakes is 78%.

Rainfall

September is the month with the least rainfall in Mountain Lakes. Rain falls for 12.5 days and accumulates 1.77" (45mm) of precipitation.

Snowfall

In Mountain Lakes, snow does not fall in June through September.

Daylight

In September, the average length of the day in Mountain Lakes is 12h and 27min.
On the first day of the month, sunrise is at 6:25 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:54 am and sunset at 6:40 pm EDT.

Sunshine

The average sunshine in September in Mountain Lakes is 8.4h.

UV index

The average daily maximum UV index in September in Mountain Lakes is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: The maximum daily UV index of 4 during September translates into the following directions:
Exercise prevention - Precautions against solar damage are endorsed. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature in Mountain Lakes?

In Mountain Lakes, 74.3°F (23.5°C) is the average high-temperature and 56.3°F (13.5°C) is the average low-temperature during September. The average heat index (a.k.a. 'feels like', 'real feel'), which factors the actual air temperature with the relative humidity, in August is computed to be 86°F (30°C).

What is the average humidity in September in Mountain Lakes?

In September, the average relative humidity in Mountain Lakes, New Jersey, is 78%.

What is the driest month in Mountain Lakes?

The month with the least rainfall in Mountain Lakes is September, when the rain falls for 12.5 days and typically collects 1.77" (45mm) of precipitation.

How much does it rain in Mountain Lakes in September?

In Mountain Lakes, in September, it is raining for 12.5 days, with typically 1.77" (45mm) of accumulated precipitation.

When it does not snow in Mountain Lakes?

June through September are months without snowfall.

Does it snow in Mountain Lakes in September?

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

How many hours of daylight does Mountain Lakes have in September?

The average day length in September in Mountain Lakes is 12h and 27min.

When are sunrise and sunset in September in Mountain Lakes?

On the first day of September in Mountain Lakes, New Jersey, sunrise is at 6:25 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:54 am and sunset at 6:40 pm EDT.

How long on average sun shines in September in Mountain Lakes?

In Mountain Lakes, the average sunshine duration in September is 8.4h.

What is the UV index intensity in September in Mountain Lakes?

In September, the average daily maximum UV index in Mountain Lakes is 4. A UV Index estimate of 3 to 5 represents a moderate vulnerability from exposure to the Sun's UV radiation.
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
Mountain Lakes, NJ

Average temperature in September - Mountain Lakes, NJ
  • Average high temperature in September: 74.3°F

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (34.5°F).

  • Average low temperature in September: 56.3°F

The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).

Average pressure in September
Mountain Lakes, NJ

Average pressure in September - Mountain Lakes, NJ
  • Average pressure in September: 30.06"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
Mountain Lakes, NJ

Average wind speed in September - Mountain Lakes, NJ
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).

Average humidity in September
Mountain Lakes, NJ

Average humidity in September - Mountain Lakes, NJ
  • Average humidity in September: 78%

The months with the highest relative humidity are February, October and December (80%).
The month with the lowest relative humidity is April (74%).

Average rainfall in September
Mountain Lakes, NJ

Average rainfall in September - Mountain Lakes, NJ
  • Average rainfall in September: 1.77"

The wettest month (with the highest rainfall) is December (3.43").
The driest month (with the least rainfall) is September (1.77").

Average rainfall days in September
Mountain Lakes, NJ

Average rainfall days in September - Mountain Lakes, NJ
  • Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (8.2 days).

Average snowfall in September
Mountain Lakes, NJ

Average snowfall in September - Mountain Lakes, NJ
  • Average snowfall in September: 0"

The month with the highest snowfall is March (4.69").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Mountain Lakes, NJ

Average snowfall days in September - Mountain Lakes, NJ
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (8.7 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Mountain Lakes, NJ

Average daylight in September / Average sunshine in September - Mountain Lakes, 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 2min

The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 24min).

Average sunshine days in September
Mountain Lakes, NJ

Average sunshine days in September - Mountain Lakes, NJ
  • Average sunshine days in September: 15.6 days

The month with the most sunshine days is November (17.4 days).
The month with the least sunshine days is April (11.2 days).

Average UV index in September
Mountain Lakes, NJ

Average UV index in September - Mountain Lakes, 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
Mountain Lakes, NJ

Average cloud cover in September - Mountain Lakes, NJ
  • Average cloud cover in September: 41

The months with the most cloud cover are February, March and December (Cloud cover 50).
The months with the least cloud cover are July and August (Cloud cover 35).

Average visibility in September
Mountain Lakes, NJ

Average visibility in September - Mountain Lakes, NJ
  • Average visibility in September: 5mi

The months with the highest visibility are January, April, July, August, October, November and December (6mi).
The months with the lowest visibility are February, March, May, June and September (5mi).

Mountain Lakes, New Jersey, USA

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