Port Jefferson, NY
Climate overview — based on NOAA 1991-2020 normals from MT SINAI, NY US.
Year-round temperatures (°F)
Climate summary
Port Jefferson has an annual average temperature of 54.7°F with about 48.5 inches of precipitation per year. The warmest month is July (average high 83.1°F), and the coldest is January (average low 26.3°F). March is typically the wettest month (4.65 in) and February the driest (3.20 in).
Best time to visit Port Jefferson
Full guide →Climate change signal
All-time records →211 of 366 (57.7%) of Port Jefferson's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 2000s | 78 | |
| 2010s | 215 | |
| 2020s | 73 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 41.0°F | 26.3°F | 33.7°F | 3.71 in | — | — |
| February | 42.9°F | 27.8°F | 35.3°F | 3.20 in | — | — |
| March | 50.0°F | 32.8°F | 41.4°F | 4.65 in | — | — |
| April | 63.7°F | 42.8°F | 53.2°F | 4.42 in | — | — |
| May | 71.7°F | 51.4°F | 61.6°F | 3.89 in | — | — |
| June | 78.2°F | 61.1°F | 69.6°F | 3.93 in | — | — |
| July | 83.1°F | 67.5°F | 75.3°F | 3.88 in | — | — |
| August | 81.8°F | 67.0°F | 74.4°F | 4.02 in | — | — |
| September | 74.7°F | 61.3°F | 68.0°F | 4.30 in | — | — |
| October | 64.8°F | 48.8°F | 56.8°F | 4.24 in | — | — |
| November | 56.0°F | 40.3°F | 48.2°F | 3.70 in | — | — |
| December | 46.1°F | 32.1°F | 39.1°F | 4.56 in | — | — |
Climate twins of Port Jefferson
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).