May weather forecast
Port Jefferson, NY

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Weather in May

The last month of the spring, May, is a refreshing month in Port Jefferson, New York, with an average temperature ranging between max 62.6°F (17°C) and min 53.6°F (12°C).

Temperature

Port Jefferson's May weather brings a rise in high-temperatures, moving from a fresh 52.9°F (11.6°C) in April to a refreshing 62.6°F (17°C). Nighttime readings during May register a minimal drop from daytime highs, averaging at a fresh 53.6°F (12°C).

Humidity

The months with the highest humidity are May and June, with an average relative humidity of 77%.

Rainfall

In Port Jefferson, New York, during May, the rain falls for 15.3 days and regularly aggregates up to 2.76" (70mm) of precipitation. In Port Jefferson, New York, during the entire year, the rain falls for 146.8 days and collects up to 33.78" (858mm) of precipitation.

Snowfall

April through September are months without snowfall.

Ocean temperature

In Port Jefferson, the average seawater temperature in May is 53.4°F (11.9°C).
Note: Swimming in 53.4°F (11.9°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

Daylight

The average length of the day in May in Port Jefferson is 14h and 29min.
On the first day of the month, sunrise is at 5:49 am and sunset at 7:49 pm. On the last day of May, sunrise is at 5:22 am and sunset at 8:17 pm EDT.

Sunshine

In Port Jefferson, the average sunshine in May is 8.7h.

UV index

In May, the average daily maximum UV index in Port Jefferson is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for average individuals.
Note: In May, the UV index of 5 transforms into the following advice:
Be vigilant - Suggestions to stave off sun damage are provided. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
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Frequently asked questions

What is the usual temperature for Port Jefferson in May?

In May, in Port Jefferson, the average high-temperature is 62.6°F (17°C), and the average low-temperature is 53.6°F (12°C).

What are the most humid months in Port Jefferson?

The months with the highest humidity in Port Jefferson are May and June, with an average relative humidity of 77%.

What is the average humidity in May in Port Jefferson?

In Port Jefferson, the average relative humidity in May is 77%.

How much does it rain in Port Jefferson in May?

In May, in Port Jefferson, the rain falls for 15.3 days. Throughout May, 2.76" (70mm) of precipitation is accumulated.

When it does not snow in Port Jefferson?

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

What is the ocean temperature in May in Port Jefferson?

In May, the average ocean temperature in Port Jefferson is 53.4°F (11.9°C). At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.

How many hours of daylight does Port Jefferson have in May?

In Port Jefferson, the average day length in May is 14h and 29min.

When is the sunrise / sunset in May in Port Jefferson?

On the first day of May in Port Jefferson, New York, sunrise is at 5:49 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 5:22 am and sunset at 8:17 pm EDT.

How many hours of sunshine does Port Jefferson have in May?

In Port Jefferson, the average sunshine duration in May is 8.7h.

What is the UV index reading in May in Port Jefferson?

In Port Jefferson, New York, the average daily maximum UV index in May is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to Sun's UV rays.
Today
Tomorrow
Long-term
YearJFMAMayJJASOND
Apr
May
Jun
Average high temperature
52.9°F 11.6°C
62.6°F 17°C
71.2°F 21.8°C
Average low temperature
44.6°F 7°C
53.6°F 12°C
63.1°F 17.3°C
Average pressure
29.98" 761mmHg
30.01" 762mmHg
29.93" 760mmHg
Average wind speed
11.2mph 18km/h
9.4mph 15.1km/h
8.6mph 13.8km/h
Average max. wind speed
12.1mph 19.5km/h
10.1mph 16.3km/h
9.3mph 15km/h
Average wind speed gusts
18.6mph 29.9km/h
16.3mph 26.2km/h
14.7mph 23.7km/h
Average humidity
73%
77%
77%
Average rainfall
2.83" 72mm
2.76" 70mm
2.72" 69mm
Average rainfall days
13.5
15.3
14.9
Average snowfall
0" 0mm
0" 0mm
0" 0mm
Average snowfall days
0.2
0
0
Average sea temperature
45.4°F 7.4°C
53.4°F 11.9°C
64.6°F 18.1°C
Average daylight
13h 2min
14h 3min
15h 1min
Average sunshine
8h 2min
8h 4min
9h 5min
Average sunshine days
15.2
14.5
13.1
Average UV index
3
5
6
Average cloud cover
44%
43%
35%
Average visibility
6mi 9.7km
6mi 9.7km
6mi 9.7km

Average temperature in May
Port Jefferson, NY

Average temperature in May - Port Jefferson, NY
  • Average high temperature in May: 62.6°F

The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is January (37.6°F).

  • Average low temperature in May: 53.6°F

The months with the highest average low temperature are July and August (71.1°F).
The coldest month (with the lowest average low temperature) is January (29.1°F).

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Average pressure in May
Port Jefferson, NY

Average pressure in May - Port Jefferson, NY
  • Average pressure in May: 30.01"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).

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Average wind speed in May
Port Jefferson, NY

Average wind speed in May - Port Jefferson, NY
  • Average wind speed in May: 9.4mph

The windiest month (with the highest average wind speed) is January (12.9mph).
The calmest month (with the lowest average wind speed) is July (8.3mph).

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Average humidity in May
Port Jefferson, NY

Average humidity in May - Port Jefferson, NY
  • Average humidity in May: 77%

The months with the highest relative humidity are May and June (77%).
The month with the lowest relative humidity is November (71%).

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Average rainfall in May
Port Jefferson, NY

Average rainfall in May - Port Jefferson, NY
  • Average rainfall in May: 2.76"

The wettest month (with the highest rainfall) is December (3.58").
The driest month (with the least rainfall) is January (2.05").

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Average rainfall days in May
Port Jefferson, NY

Average rainfall days in May - Port Jefferson, NY
  • Average rainfall days in May: 15.3 days

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).

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Average snowfall in May
Port Jefferson, NY

Average snowfall in May - Port Jefferson, NY
  • Average snowfall in May: 0"

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

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Average snowfall days in May
Port Jefferson, NY

Average snowfall days in May - Port Jefferson, NY
  • Average snowfall days in May: 0 days

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

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Average sea temperature in May
Port Jefferson, NY

Average sea temperature in May - Port Jefferson, NY
  • Average sea temperature in May: 53.4°F

The best month for swimming (with the highest average sea temperature) is August (74°F).
The coldest month (with the lowest average sea temperature) is February (39.7°F).

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Average daylight in May /
Average sunshine in May
Port Jefferson, NY

Average daylight in May / Average sunshine in May - Port Jefferson, NY
  • Average daylight in May: 14h 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 May: 8h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

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Average sunshine days in May
Port Jefferson, NY

Average sunshine days in May - Port Jefferson, NY
  • Average sunshine days in May: 14.5 days

The month with the most sunshine days is November (20.5 days).
The month with the least sunshine days is July (13 days).

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Average UV index in May
Port Jefferson, NY

Average UV index in May - Port Jefferson, NY
  • Average UV index in May: 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, November and December (UV index 2).

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Average cloud cover in May
Port Jefferson, NY

Average cloud cover in May - Port Jefferson, NY
  • Average cloud cover in May: 43

The month with the most cloud cover is December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 28).

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Average visibility in May
Port Jefferson, NY

Average visibility in May - Port Jefferson, NY
  • Average visibility in May: 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).

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Port Jefferson, New York, USA

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