May weather forecastPort Jefferson, NY
May
Weather in May
May, the last month of the spring in Port Jefferson, is an enjoyable month, with an average temperature ranging between max 62.6°F (17°C) and min 53.6°F (12°C).Temperature
The onset of May brings a rise in the average high-temperature, elevating from a cool 52.9°F (11.6°C) in April to an enjoyable 62.6°F (17°C). Port Jefferson sustains an average of approximately a fresh 53.6°F (12°C) during May nights, with little variation from daytime highs.Humidity
The months with the highest humidity are May and June, with an average relative humidity of 77%.Rainfall
In Port Jefferson, during May, the rain falls for 15.3 days and regularly aggregates up to 2.76" (70mm) of precipitation. Throughout the year, there are 146.8 rainfall days, and 33.78" (858mm) of precipitation is accumulated.Snowfall
In Port Jefferson, snow does not fall in April through September.Ocean temperature
In Port Jefferson, in May, the average water temperature is 53.4°F (11.9°C).Note: If planning to swim in 53.4°F (11.9°C) under 50°F (10°C), wear a protective suit. Neglecting this advice might cause immediate cold shock and troubled breathing. A splash around 55.4°F (13°C) is not much warmer.
Daylight
In Port Jefferson, the average length of the day in May 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
The average sunshine in May is 8.7h.UV index
The average daily maximum UV index in May in Port Jefferson is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: The UV index of 5 in May translates into these instructions:
Take precautions - Protection against sun damage is advised. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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).
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).
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).
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%).
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").
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).
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").
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).
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).
Average daylight in May /
Average sunshine in May
Port Jefferson, NY
- Average daylight in May: 14h and 30min
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 42min
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).
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).
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).
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).
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).
