Port Jefferson
New York, USA
Long-term weather forecast
Long-term weather forecast

Monthly weather forecast and climate
Port Jefferson, NY

January, the same as December, is another cold winter month in Port Jefferson, New York, with average temperature fluctuating between 29.1°F (-1.6°C) and 37.6°F (3.1°C). With an average high-temperature of 37.6°F (3.1°C) and an average low-temperature of 29.1°F (-1.6°C), January is the coldest month. Weather in January »

The last month of the winter, February, is another cold month in Port Jefferson, New York, with temperature in the range of an average low of 30.4°F (-0.9°C) and an average high of 38.8°F (3.8°C). In Port Jefferson, the average high-temperature is essentially the same as in January - a still cold 38.8°F (3.8°C). Weather in February »

March, the first month of the spring, in Port Jefferson, is a chilly month, with average temperature fluctuating between 43.9°F (6.6°C) and 36°F (2.2°C). In March, the average high-temperature is relatively the same as in February - a frosty 43.9°F (6.6°C). Weather in March »

April in Port Jefferson, New York, is a fresh spring month, with temperature in the range of an average high of 52.9°F (11.6°C) and an average low of 44.6°F (7°C). In Port Jefferson, the average high-temperature increases, from a frosty 43.9°F (6.6°C) in March, to a fresh 52.9°F (11.6°C). Weather in April »

The last month of the spring, May, is a comfortable month in Port Jefferson, New York, with average temperature fluctuating between 62.6°F (17°C) and 53.6°F (12°C). In Port Jefferson, the average high-temperature increases, from a fresh 52.9°F (11.6°C) in April, to an enjoyable 62.6°F (17°C). Weather in May »

June, the first month of the summer, in Port Jefferson, is a pleasant month, with average temperature fluctuating between 63.1°F (17.3°C) and 71.2°F (21.8°C). In Port Jefferson, the average high-temperature in June slightly increases, from a comfortable 62.6°F (17°C) in May, to an agreeable 71.2°F (21.8°C). Weather in June »

July is a warm summer month in Port Jefferson, New York, with average temperature varying between 79.2°F (26.2°C) and 71.1°F (21.7°C). With an average high-temperature of 79.2°F (26.2°C) and an average low-temperature of 71.1°F (21.7°C), July is the warmest month. Weather in July »

The last month of the summer, August, is also a moderately hot month in Port Jefferson, New York, with average temperature fluctuating between 78.4°F (25.8°C) and 71.1°F (21.7°C). In Port Jefferson, New York, the average high-temperature is relatively the same as in July - a still warm 78.4°F (25.8°C). Weather in August »

September, the first month of the autumn, in Port Jefferson, is also an agreeable month, with average temperature varying between 72.3°F (22.4°C) and 64.8°F (18.2°C). In Port Jefferson, the average high-temperature marginally drops, from a moderately hot 78.4°F (25.8°C) in August, to a pleasant 72.3°F (22.4°C). Weather in September »

October, the same as September, is another comfortable autumn month in Port Jefferson, New York, with average temperature fluctuating between 62.6°F (17°C) and 55.4°F (13°C). In October, the average high-temperature drops, from a pleasant 72.3°F (22.4°C) in September, to an enjoyable 62.6°F (17°C). Weather in October »

November, the last month of the autumn, in Port Jefferson, is also a fresh month, with temperature in the range of an average high of 51.8°F (11°C) and an average low of 44.1°F (6.7°C). In Port Jefferson, the average high-temperature in November drops, from a comfortable 62.6°F (17°C) in October, to a fresh 51.8°F (11°C). Weather in November »

December, the first month of the winter, in Port Jefferson, is still a chilly month, with temperature in the range of an average low of 36.5°F (2.5°C) and an average high of 43.7°F (6.5°C). In Port Jefferson, the average high-temperature in December marginally drops, from a cool 51.8°F (11°C) in November, to a chilly 43.7°F (6.5°C). Weather in December »

What is the coldest month in Port Jefferson?

The coldest month is January, with an average high-temperature of 37.6°F (3.1°C) and an average low-temperature of 29.1°F (-1.6°C).

How much does it rain in Port Jefferson?

In Port Jefferson, during the entire year, the rain falls for 146.8 days and collects up to 33.78" (858mm) of precipitation.

What is the driest month in Port Jefferson?

January is the month with the least rainfall. Rain falls for 6.8 days and accumulates 2.05" (52mm) of precipitation.

When does it snow in Port Jefferson?

January through March, October through December are months with snowfall.

How many days does it snow in Port Jefferson?

In Port Jefferson, during the entire year, snow falls for 12.6 days, and aggregates up to 5.59" (142mm) of snow.

When is the lowest UV index in Port Jefferson?

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

When is the ocean coldest in Port Jefferson?

February is the month with the coldest seawater in Port Jefferson, New York, with an average ocean temperature of 39.7°F (4.3°C).

What is the month with the least sunshine in Port Jefferson?

The month with the least sunshine is February, with an average of 4.7h of sunshine.

When does it snow the most in Port Jefferson?

The month with the most snowfall in Port Jefferson is March when snow falls for 2.3 days and typically aggregates up to 2.13" (54mm) of snow.

When it does not snow in Port Jefferson?

In Port Jefferson snow does not fall in April through September.

What are the most humid months in Port Jefferson?

May and June, with an average relative humidity of 77%, are most humid months in Port Jefferson, New York.

When are the longest days in Port Jefferson?

With an average of 15.1h of daylight, June has the longest days of the year in Port Jefferson.

What are the months with the highest UV index in Port Jefferson?

Months with the highest UV index in Port Jefferson are June through August, with an average maximum UV index of 6.

What is the warmest month in Port Jefferson?

The warmest month in Port Jefferson, New York, is July, with an average high-temperature of 79.2°F (26.2°C) and an average low-temperature of 71.1°F (21.7°C).

What month has the most sunshine in Port Jefferson?

With an average of 10.6h of sunshine, July has the most sunshine of the year in Port Jefferson, New York.

What is the month with the warmest ocean in Port Jefferson?

August is the month with the warmest seawater in Port Jefferson, with an average ocean temperature of 73.9°F (23.3°C).

What is the least humid month in Port Jefferson?

November is the least humid month, with an average relative humidity of 71%.

What is the rainiest month in Port Jefferson?

December is the month with the most rainfall in Port Jefferson. Rain falls for 11.4 days and accumulates 3.58" (91mm) of precipitation.

What is the month with the shortest days in Port Jefferson?

The month with the shortest days in Port Jefferson, New York, is December, with an average of 9.3h of daylight.
Average temperature - Port Jefferson, NY
Average humidity - Port Jefferson, NY
Average rainfall - Port Jefferson, NY
Average rainfall days - Port Jefferson, NY

The month with the highest number of rainy days is July (16.5 days).
The month with the least rainy days is January (6.8 days).

Average snowfall - Port Jefferson, NY
Average snowfall days - Port Jefferson, NY

The month with the highest number of snowfall days is February (4.4 days).
Months with the least snowfall days are May, June, July, August and September (0 days).

Average sea temperature - Port Jefferson, NY

The best month for swimming (with the highest average sea temperature) is August (23.3°C).
The coldest month (with the lowest average sea temperature) is February (4.3°C).

Average daylight / Average sunshine - Port Jefferson, NY

The month with the longest days is June (Average daylight: 15.1h).
The month with the shortest days is December (Average daylight: 9.3h).

The month with the most sunshine is July (Average sunshine: 10.6h).
The month with the least sunshine is February (Average sunshine: 4.7h).

Average UV index - Port Jefferson, NY