April weather forecastPort Jefferson, NY
April
Weather in April
April in Port Jefferson, New York, is a cool spring month, with temperature in the range of an average low of 44.6°F (7°C) and an average high of 52.9°F (11.6°C).Temperature
The arrival of April brings a change in Port Jefferson's weather, with average high-temperatures moving from March's chilly 43.9°F (6.6°C) to a fresh 52.9°F (11.6°C). Throughout April, a modest shift from daytime highs is anticipated, with an average low-temperature of 44.6°F (7°C).Humidity
In Port Jefferson, the average relative humidity in April is 73%.Rainfall
In Port Jefferson, in April, it is raining for 13.5 days, with typically 2.83" (72mm) of accumulated 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, the average seawater temperature in April is 45.3°F (7.4°C).Note: 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.
Daylight
The average length of the day in April is 13h and 20min.On the first day of April, sunrise is at 6:34 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 5:50 am and sunset at 7:48 pm EDT.
Sunshine
In April, the average sunshine is 8.4h.UV index
In Port Jefferson, the average daily maximum UV index in April is 3. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: In April, an average UV index of 3 transforms into the following instructions:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in April
Port Jefferson, NY
- Average high temperature in April: 52.9°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 April: 44.6°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 April
Port Jefferson, NY
- Average pressure in April: 29.98"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 April
Port Jefferson, NY
- Average wind speed in April: 11.2mph
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 April
Port Jefferson, NY
- Average humidity in April: 73%
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 April
Port Jefferson, NY
- Average rainfall in April: 2.83"
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 April
Port Jefferson, NY
- Average rainfall days in April: 13.5 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 April
Port Jefferson, NY
- Average snowfall in April: 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 April
Port Jefferson, NY
- Average snowfall days in April: 0.2 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 April
Port Jefferson, NY
- Average sea temperature in April: 45.4°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 April /
Average sunshine in April
Port Jefferson, NY
- Average daylight in April: 13h and 18min
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 April: 8h and 24min
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 April
Port Jefferson, NY
- Average sunshine days in April: 15.2 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 April
Port Jefferson, NY
- Average UV index in April: 3
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 April
Port Jefferson, NY
- Average cloud cover in April: 44
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 April
Port Jefferson, NY
- Average visibility in April: 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).





