Port Jefferson, New York Weather
Fireflies rise from the lawn. Day 78 of spring. Read this microseason across nine climate regions →
Port Jefferson weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 5Overcast——87°57°—
- SaturdayJun 6Light Drizzle47%0.02″90°60°+3°
- SundayJun 7Overcast47%0.05″80°65°-10°
- MondayJun 8Overcast——76°58°-4°
- TuesdayJun 9Clear——81°62°+5°
- WednesdayJun 10Overcast——80°62°-1°
- ThursdayJun 11Overcast19%—78°63°-2°
AQI 48 (Good), driven by PM2.5. AQI down 42 over the last 6 hours — air quality is improving sharply. PM2.5 at 16.8 µg/m³ (AQI 65) with a 0.84 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 16.8 µg/m³ (AQI 65) with a 0.84 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.84
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
The higher the clouds, the finer the weather.
- Moonrise
- 3:54 AM
- Moonset
- 1:54 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Port Jefferson at a glance
- Today vs. normal: 15°F below the seasonal normal for this latitude
- Last frost: April 22 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Port Jefferson
SPC has placed Port Jefferson in the Marginal Risk category for severe thunderstorms tomorrow.
- TODAYNONENo severe risk
- TOMORROWMRGLMarginal Risk
- DAY 3TSTMGeneral Thunderstorms
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
Beaches near Port Jefferson
- Robert Moses Beach24.9 mi
Each linked page shows live water temperature, wave height, swim and surf verdicts, tides, and rip-current risk from NDBC + NOAA + NWS data.