May weather in Port Jefferson, NY
The average temperature in Port Jefferson in May is 61.6°F (51.4°F–71.7°F). Average precipitation: 3.89 inches.
May is a spring month in Port Jefferson, and is warmer than the annual average of 54.7°F. Daily temperatures swing about 20.3°F between overnight low and afternoon high. Daylight averages about 14h 17m. For travel, May is one of the best months of the year to visit.
Avg High
71.7°F
Avg Low
51.4°F
Precipitation
3.89 in
Daylight
14h 17m
May records in Port Jefferson
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| May 1 | 78.1°F (2010) | 30.0°F (2008) | 2.60 in (2014) |
| May 2 | 80.1°F (2010) | 37.0°F (2015) | 0.64 in (2017) |
| May 3 | 82.9°F (2018) | 37.9°F (2007) | 1.54 in (2010) |
| May 4 | 82.0°F (2015) | 36.0°F (2003) | 0.90 in (2021) |
| May 5 | 81.0°F (2015) | 33.1°F (2003) | 1.02 in (2017) |
| May 6 | 78.1°F (2010) | 37.0°F (2024) | 1.52 in (2025) |
| May 7 | 80.1°F (2003) | 35.1°F (2007) | 1.00 in (2022) |
| May 8 | 80.1°F (2015) | 36.0°F (2007) | 0.35 in (2013) |
| May 9 | 80.1°F (2007) | 35.1°F (2020) | 1.05 in (2012) |
| May 10 | 82.0°F (2014) | 37.9°F (2020) | 0.76 in (2012) |
| May 11 | 80.1°F (2015) | 39.9°F (2010) | 0.43 in (2013) |
| May 12 | 84.0°F (2015) | 39.9°F (2020) | 3.18 in (2006) |
| May 13 | 82.9°F (2015) | 39.9°F (2020) | 1.46 in (2002) |
| May 14 | 77.0°F (2007) | 37.9°F (2007) | 0.64 in (2002) |
| May 15 | 81.0°F (2018) | 41.0°F (2013) | 0.65 in (2012) |
| May 16 | 78.1°F (2007) | 39.0°F (2002) | 1.21 in (2024) |
| May 17 | 82.9°F (2017) | 44.1°F (2003) | 1.58 in (2011) |
| May 18 | 93.0°F (2017) | 37.0°F (2003) | 2.10 in (2002) |
| May 19 | 91.0°F (2017) | 36.0°F (2002) | 1.21 in (2011) |
| May 20 | 88.0°F (2018) | 42.1°F (2002) | 0.38 in (2008) |
| May 21 | 84.0°F (2013) | 37.9°F (2002) | 1.74 in (2023) |
| May 22 | 87.1°F (2021) | 39.0°F (2002) | 0.60 in (2025) |
| May 23 | 86.0°F (2021) | 45.0°F (2002) | 0.82 in (2025) |
| May 24 | 86.0°F (2021) | 43.0°F (2006) | 0.78 in (2013) |
| May 25 | 88.0°F (2014) | 42.1°F (2017) | 0.55 in (2013) |
| May 26 | 89.1°F (2010) | 46.0°F (2013) | 2.65 in (2003) |
| May 27 | 88.0°F (2010) | 41.0°F (2013) | 0.54 in (2008) |
| May 28 | 84.9°F (2012) | 46.9°F (2013) | 2.00 in (2024) |
| May 29 | 84.9°F (2012) | 44.1°F (2008) | 2.60 in (2021) |
| May 30 | 89.1°F (2013) | 46.9°F (2014) | 1.00 in (2021) |
| May 31 | 91.0°F (2013) | 48.0°F (2008) | 1.03 in (2019) |