January weather in Port Jefferson, NY
The average temperature in Port Jefferson in January is 33.7°F (26.3°F–41.0°F). Average precipitation: 3.71 inches.
January is a winter month in Port Jefferson, and is cooler than the annual average of 54.7°F. Daily temperatures swing about 14.7°F between overnight low and afternoon high. Daylight averages about 9h 22m. For travel, January is cold.
Avg High
41.0°F
Avg Low
26.3°F
Precipitation
3.71 in
Daylight
9h 22m
January records in Port Jefferson
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| January 1 | 54.0°F (2011) | 6.1°F (2018) | 1.32 in (2019) |
| January 2 | 55.9°F (2021) | 14.0°F (2018) | 1.01 in (2003) |
| January 3 | 53.1°F (2004) | 10.0°F (2008) | 2.06 in (2006) |
| January 4 | 59.0°F (2015) | -0.9°F (2014) | 0.90 in (2018) |
| January 5 | 63.0°F (2019) | 10.0°F (2018) | 0.66 in (2004) |
| January 6 | 71.1°F (2014) | 8.1°F (2018) | 0.54 in (2014) |
| January 7 | 63.0°F (2012) | 3.9°F (2018) | 0.70 in (2017) |
| January 8 | 60.1°F (2008) | 7.0°F (2015) | 0.15 in (2024) |
| January 9 | 63.0°F (2008) | 8.1°F (2004) | 0.15 in (2019) |
| January 10 | 64.9°F (2016) | 1.0°F (2004) | 3.69 in (2024) |
| January 11 | 62.1°F (2016) | 5.0°F (2004) | 1.87 in (2008) |
| January 12 | 68.0°F (2020) | 17.1°F (2016) | 1.39 in (2012) |
| January 13 | 60.1°F (2017) | 19.9°F (2003) | 1.96 in (2024) |
| January 14 | 63.0°F (2013) | 5.0°F (2004) | 1.36 in (2006) |
| January 15 | 59.0°F (2020) | 7.0°F (2011) | 0.83 in (2006) |
| January 16 | 60.1°F (2021) | -2.0°F (2004) | 0.72 in (2013) |
| January 17 | 57.0°F (2021) | 15.1°F (2015) | 2.15 in (2022) |
| January 18 | 59.0°F (2006) | 6.1°F (2003) | 0.98 in (2006) |
| January 19 | 53.1°F (2025) | 5.0°F (2003) | 0.67 in (2015) |
| January 20 | 57.9°F (2006) | 17.1°F (2004) | 1.37 in (2019) |
| January 21 | 61.0°F (2006) | 9.0°F (2019) | 0.51 in (2012) |
| January 22 | 53.1°F (2006) | 1.0°F (2019) | 0.15 in (2014) |
| January 23 | 59.0°F (2018) | 3.0°F (2011) | 1.55 in (2016) |
| January 24 | 57.0°F (2018) | 6.1°F (2011) | 1.65 in (2019) |
| January 25 | 59.0°F (2020) | 3.0°F (2004) | 0.76 in (2020) |
| January 26 | 57.9°F (2024) | 10.9°F (2025) | 1.90 in (2026) |
| January 27 | 61.0°F (2012) | 12.0°F (2025) | 1.19 in (2011) |
| January 28 | 55.9°F (2006) | 6.1°F (2003) | 0.81 in (2004) |
| January 29 | 51.1°F (2018) | 14.0°F (2014) | 1.00 in (2022) |
| January 30 | 61.0°F (2006) | 6.1°F (2014) | 0.42 in (2018) |
| January 31 | 68.0°F (2013) | 3.9°F (2019) | 0.47 in (2013) |