September weather in South Portland, ME
The average temperature in South Portland in September is 61.6°F (52.1°F–71.1°F). Average precipitation: 3.77 inches.
September is a fall month in South Portland, and is warmer than the annual average of 47.5°F. Daily temperatures swing about 19°F between overnight low and afternoon high. Expect about 9 days with precipitation. Daylight averages about 12h 17m. For travel, September is one of the best months of the year to visit.
Avg High
71.1°F
Avg Low
52.1°F
Precipitation
3.77 in
Daylight
12h 17m
September records in South Portland
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 93.0°F (1969) | 39.0°F (2002) | 3.04 in (1949) |
| September 2 | 93.9°F (1953) | 41.0°F (1949) | 2.26 in (2013) |
| September 3 | 93.0°F (1973) | 39.0°F (1958) | 2.90 in (1972) |
| September 4 | 88.0°F (2008) | 39.0°F (1987) | 1.84 in (1966) |
| September 5 | 90.0°F (1971) | 39.9°F (1965) | 1.27 in (1994) |
| September 6 | 91.9°F (2018) | 39.9°F (1989) | 3.79 in (2008) |
| September 7 | 95.0°F (1945) | 33.1°F (1962) | 1.73 in (2008) |
| September 8 | 93.0°F (1960) | 34.0°F (1955) | 1.11 in (1969) |
| September 9 | 93.0°F (2002) | 37.0°F (1952) | 3.12 in (1969) |
| September 10 | 89.1°F (2002) | 37.0°F (1953) | 3.00 in (1999) |
| September 11 | 95.0°F (1983) | 35.1°F (1963) | 7.49 in (1954) |
| September 12 | 91.0°F (1947) | 36.0°F (1958) | 2.44 in (1960) |
| September 13 | 86.0°F (1952) | 34.0°F (1954) | 1.68 in (2013) |
| September 14 | 88.0°F (1993) | 28.0°F (1963) | 1.79 in (1944) |
| September 15 | 90.0°F (1993) | 28.9°F (1963) | 2.12 in (1944) |
| September 16 | 90.0°F (1941) | 28.0°F (1964) | 4.44 in (1999) |
| September 17 | 88.0°F (1941) | 30.0°F (1948) | 1.01 in (1995) |
| September 18 | 90.0°F (1955) | 32.0°F (1950) | 2.29 in (2023) |
| September 19 | 87.1°F (1946) | 30.9°F (1956) | 1.15 in (2022) |
| September 20 | 87.1°F (1985) | 27.0°F (1964) | 2.04 in (1987) |
| September 21 | 91.0°F (1978) | 30.0°F (1956) | 1.27 in (1974) |
| September 22 | 89.1°F (1965) | 27.0°F (1962) | 1.21 in (1983) |
| September 23 | 89.1°F (2019) | 30.9°F (1955) | 4.04 in (1994) |
| September 24 | 88.0°F (1959) | 28.0°F (1953) | 1.12 in (1985) |
| September 25 | 88.0°F (1970) | 28.9°F (1963) | 2.42 in (1961) |
| September 26 | 90.0°F (2007) | 27.0°F (1950) | 2.21 in (2008) |
| September 27 | 84.0°F (2014) | 28.9°F (1955) | 1.51 in (1993) |
| September 28 | 84.9°F (2025) | 26.1°F (1965) | 1.12 in (2008) |
| September 29 | 84.9°F (1945) | 27.0°F (1947) | 1.56 in (1963) |
| September 30 | 84.9°F (1948) | 23.0°F (1941) | 5.56 in (2015) |