September weather forecast
Lake Ronkonkoma, NY

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Weather in September

September, the first month of the autumn in Lake Ronkonkoma, is still a pleasant month, with an average temperature fluctuating between 65.3°F (18.5°C) and 72.1°F (22.3°C).

Temperature

Lake Ronkonkoma's September weather shows a modest shift in high-temperatures, falling from August's warm 78.1°F (25.6°C) to a pleasant 72.1°F (22.3°C). Lake Ronkonkoma maintains an average low-temperature of 65.3°F (18.5°C) throughout September's nights.

Humidity

In September, the average relative humidity is 74%.

Rainfall

In Lake Ronkonkoma, in September, during 12.8 rainfall days, 2.48" (63mm) of precipitation is typically accumulated. Throughout the year, there are 155.3 rainfall days, and 34.84" (885mm) of precipitation is accumulated.

Snowfall

In Lake Ronkonkoma, snow does not fall in April, June through September and November.

Daylight

In September, the average length of the day is 12h and 27min.
On the first day of the month, sunrise is at 6:20 am and sunset at 7:24 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:35 pm EDT.

Sunshine

The average sunshine in September in Lake Ronkonkoma is 9.2h.

UV index

In September, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.
Note: In September, a daily maximum UV index of 5 leads to the following instructions:
Exercise prevention - Protecting skin and eyes from harm is required. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Updated: Aug 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Lake Ronkonkoma in September?

In Lake Ronkonkoma, 72.1°F (22.3°C) is the average high-temperature and 65.3°F (18.5°C) is the average low-temperature during September.

What is the average humidity in September?

The average relative humidity in September is 74%.

How much does it rain in September?

In September, the rain falls for 12.8 days. Throughout September, 2.48" (63mm) of precipitation is accumulated.

When it does not snow?

In Lake Ronkonkoma, snow does not fall in April, June through September and November.

Does it snow in September?

In Lake Ronkonkoma, New York, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

In Lake Ronkonkoma, the average day length in September is 12h and 27min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:20 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:35 pm EDT.

How long on average sun shines in September?

In September, the average sunshine duration is 9.2h.

What is the UV index intensity in September?

In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium hazard to health from unprotected exposure to 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
Lake Ronkonkoma, NY

Average temperature in September - Lake Ronkonkoma, NY
  • Average high temperature in September: 72.1°F

The warmest month (with the highest average high temperature) is August (78.1°F).
The month with the lowest average high temperature is January (37.9°F).

  • Average low temperature in September: 65.3°F

The month with the highest average low temperature is August (71.8°F).
The coldest month (with the lowest average low temperature) is January (30.2°F).

Average pressure in September
Lake Ronkonkoma, NY

Average pressure in September - Lake Ronkonkoma, NY
  • Average pressure in September: 30.05"Hg

The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Lake Ronkonkoma, NY

Average wind speed in September - Lake Ronkonkoma, NY
  • Average wind speed in September: 10.4mph

The windiest month (with the highest average wind speed) is January (13.8mph).
The calmest months (with the lowest average wind speed) are July and August (9mph).

Average humidity in September
Lake Ronkonkoma, NY

Average humidity in September - Lake Ronkonkoma, NY
  • Average humidity in September: 74%

The months with the highest relative humidity are May and June (78%).
The month with the lowest relative humidity is November (71%).

Average rainfall in September
Lake Ronkonkoma, NY

Average rainfall in September - Lake Ronkonkoma, NY
  • Average rainfall in September: 2.48"

The wettest month (with the highest rainfall) is December (3.74").
The driest month (with the least rainfall) is January (2.17").

Average rainfall days in September
Lake Ronkonkoma, NY

Average rainfall days in September - Lake Ronkonkoma, NY
  • Average rainfall days in September: 12.8 days

The month with the highest number of rainy days is July (17.7 days).
The month with the least rainy days is January (8.3 days).

Average snowfall in September
Lake Ronkonkoma, NY

Average snowfall in September - Lake Ronkonkoma, NY
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.13").
The months with the least snowfall are April, June, July, August, September and November (0").

Average snowfall days in September
Lake Ronkonkoma, NY

Average snowfall days in September - Lake Ronkonkoma, NY
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (4.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Lake Ronkonkoma, NY

Average daylight in September / Average sunshine in September - Lake Ronkonkoma, NY
  • 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: 9h and 1min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in September
Lake Ronkonkoma, NY

Average sunshine days in September - Lake Ronkonkoma, NY
  • Average sunshine days in September: 15.1 days

The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is July (11.3 days).

Average UV index in September
Lake Ronkonkoma, NY

Average UV index in September - Lake Ronkonkoma, NY
  • Average UV index in September: 5

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 and December (UV index 2).

Average cloud cover in September
Lake Ronkonkoma, NY

Average cloud cover in September - Lake Ronkonkoma, NY
  • Average cloud cover in September: 31

The month with the most cloud cover is December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in September
Lake Ronkonkoma, NY

Average visibility in September - Lake Ronkonkoma, NY
  • 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).

Lake Ronkonkoma, New York, USA

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