September weather in Port Jefferson, OH
The average temperature in Port Jefferson in September is 65.2°F (52.5°F–77.9°F). Average precipitation: 3.11 inches.
September is a fall month in Port Jefferson, and is warmer than the annual average of 50.9°F. Daily temperatures swing about 25.4°F between overnight low and afternoon high. Expect about 9 days with precipitation. Daylight averages about 12h 15m. For travel, September is one of the best months of the year to visit.
Avg High
77.9°F
Avg Low
52.5°F
Precipitation
3.11 in
Daylight
12h 15m
September records in Port Jefferson
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 91.9°F (1995) | 45.0°F (2009) | 2.62 in (2003) |
| September 2 | 96.1°F (2011) | 45.0°F (1994) | 1.62 in (1959) |
| September 3 | 98.1°F (2011) | 45.0°F (1994) | 1.54 in (1993) |
| September 4 | 97.0°F (2011) | 39.9°F (1997) | 0.75 in (1962) |
| September 5 | 93.9°F (2018) | 42.1°F (1997) | 2.25 in (2022) |
| September 6 | 93.0°F (2018) | 39.9°F (1984) | 1.16 in (2018) |
| September 7 | 93.9°F (2002) | 39.9°F (1988) | 1.40 in (2018) |
| September 8 | 96.1°F (2002) | 39.9°F (2024) | 3.12 in (2020) |
| September 9 | 95.0°F (2002) | 39.9°F (2024) | 1.73 in (2008) |
| September 10 | 93.0°F (1983) | 42.1°F (2024) | 2.18 in (2001) |
| September 11 | 95.0°F (1983) | 39.0°F (1993) | 1.11 in (2000) |
| September 12 | 95.0°F (2013) | 39.0°F (1993) | 1.49 in (1972) |
| September 13 | 91.9°F (2019) | 42.1°F (1985) | 1.01 in (1972) |
| September 14 | 91.9°F (1991) | 39.9°F (1985) | 1.61 in (1979) |
| September 15 | 93.0°F (1998) | 37.9°F (2007) | 1.64 in (1989) |
| September 16 | 91.0°F (1991) | 39.0°F (2011) | 1.75 in (1996) |
| September 17 | 91.0°F (1991) | 37.0°F (1984) | 1.30 in (1969) |
| September 18 | 87.1°F (2024) | 39.0°F (1984) | 1.03 in (1986) |
| September 19 | 91.0°F (2018) | 37.9°F (2012) | 1.53 in (1952) |
| September 20 | 91.0°F (1978) | 36.0°F (1991) | 1.55 in (1966) |
| September 21 | 91.9°F (2018) | 33.1°F (1991) | 1.58 in (2013) |
| September 22 | 93.0°F (2024) | 33.1°F (1991) | 1.40 in (2021) |
| September 23 | 93.0°F (2017) | 30.0°F (1995) | 1.29 in (2021) |
| September 24 | 93.9°F (2017) | 30.0°F (1995) | 1.77 in (1972) |
| September 25 | 91.0°F (2017) | 33.1°F (2012) | 2.16 in (1961) |
| September 26 | 91.9°F (2017) | 35.1°F (1989) | 1.95 in (2011) |
| September 27 | 91.9°F (2017) | 33.1°F (1991) | 1.52 in (2002) |
| September 28 | 88.0°F (1998) | 34.0°F (1989) | 1.15 in (2004) |
| September 29 | 89.1°F (2025) | 32.0°F (2000) | 0.75 in (1999) |
| September 30 | 89.1°F (2025) | 35.1°F (1992) | 1.55 in (1955) |