Live Weather & Forecast
Weather in Port Jefferson
New York, United States · Real-time conditions & 3-day outlook
18°C
Feels like 18°C
65°F / Feels 65°F
Partly cloudy
Port Jefferson, New York
🌙 Nighttime
Updated: 2026-04-15 21:30
Humidity
65%
Wind
13.7 km/h WSW
Wind Gust
28.7 km/h
Pressure
1012 mb
Visibility
16 km
UV Index
0
(Low)
Precipitation
0 mm
Cloud Cover
75%
Dew Point
11°C
Wind Degree
238°
Air Quality Index
US EPA: Moderate
UK DEFRA: Low (2)
CO
228.9 μg/m³
NO₂
20.6 μg/m³
O₃
79 μg/m³
SO₂
4.5 μg/m³
PM 2.5
16.2 μg/m³
PM 10
18.3 μg/m³
Today's Hourly Forecast
24-hour breakdown for Port Jefferson, New York
12 AM
18°
Clear
1 AM
18°
Patchy rain nearby
2 AM
17°
Clear
3 AM
16°
Clear
4 AM
16°
Clear
5 AM
16°
Clear
6 AM
16°
Clear
7 AM
18°
Sunny
8 AM
19°
Sunny
9 AM
20°
Sunny
10 AM
22°
Partly Cloudy
11 AM
23°
Sunny
12 PM
24°
Sunny
1 PM
25°
Sunny
2 PM
27°
Sunny
3 PM
28°
Sunny
4 PM
28°
Sunny
5 PM
27°
Sunny
6 PM
26°
Sunny
7 PM
23°
Sunny
8 PM
21°
Clear
9 PM
18°
Partly cloudy
10 PM
20°
Clear
11 PM
18°
Clear
3-Day Forecast
Daily overview for Port Jefferson, New York
Today
Sunny
29°
/
15°
🌧️ 0% chance of rain
💧 Avg. humidity: 64%
💨 Max wind: 22.7 km/h
🌧️ Total precip: 0.06 mm
☀️ UV Index: 2
🌅 Sunrise: 06:13 AM
🌇 Sunset: 07:32 PM
🌙 Waning Crescent
🌑 Moon: 8% lit
Thu, Apr 16
Sunny
25°
/
14°
🌧️ 0% chance of rain
💧 Avg. humidity: 69%
💨 Max wind: 23.8 km/h
🌧️ Total precip: 0 mm
☀️ UV Index: 1.7
🌅 Sunrise: 06:11 AM
🌇 Sunset: 07:33 PM
🌙 Waning Crescent
🌑 Moon: 3% lit
Fri, Apr 17
Partly Cloudy
21°
/
13°
🌧️ 0% chance of rain
💧 Avg. humidity: 78%
💨 Max wind: 20.5 km/h
🌧️ Total precip: 0 mm
☀️ UV Index: 1.6
🌅 Sunrise: 06:10 AM
🌇 Sunset: 07:35 PM
🌙 New Moon
🌑 Moon: 0% lit
Best Time to Visit Port Jefferson
Plan your trip to Port Jefferson, United States around the most favorable weather conditions.
Peak Season
June – September
Warm, dry summers — ideal for outdoor activities.
Shoulder Season
April – May, October
Fewer crowds, moderate prices, mild weather.
Off Season
November – March
Cooler temperatures; some regions may experience rain or snow.
Frequently Asked Questions
What is the current weather in Port Jefferson?
Current conditions in Port Jefferson: Partly cloudy, temperature 18°C, humidity 65%.
What is the best time to visit Port Jefferson?
The best time to visit Port Jefferson is typically June – September. Warm, dry summers — ideal for outdoor activities.
What is the climate like in Port Jefferson?
Port Jefferson is located at approximately 40.9° latitude. It has a temperate climate with warm summers and cold winters.
Does it rain a lot in Port Jefferson?
The wettest period in Port Jefferson is typically during November – March. Cooler temperatures; some regions may experience rain or snow.
What should I pack for a trip to Port Jefferson?
For visits to Port Jefferson during June – September: light clothing and sun protection. For November – March: layers and a waterproof jacket are recommended.
What country is Port Jefferson in?
Port Jefferson is located in United States, in the state of New York.
What are the public holidays in Port Jefferson in 2026?
View the 2026 public holidays for Port Jefferson on our Holidays page.
What are the GPS coordinates used for the weather forecast in Port Jefferson?
The weather forecast for Port Jefferson uses coordinates 40.9465, -73.0691.