September weather in New Haven, CT
The average temperature in New Haven in September is 66.0°F (57.3°F–74.7°F). Average precipitation: 4.03 inches.
September is a fall month in New Haven, and is warmer than the annual average of 52°F. Daily temperatures swing about 17.4°F between overnight low and afternoon high. Expect about 9 days with precipitation. Daylight averages about 12h 16m. For travel, September is a comfortable month to visit.
Avg High
74.7°F
Avg Low
57.3°F
Precipitation
4.03 in
Daylight
12h 16m
September records in New Haven
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 91.0°F (2010) | 48.9°F (1975) | 3.97 in (2021) |
| September 2 | 91.0°F (1953) | 46.0°F (1949) | 2.86 in (2002) |
| September 3 | 90.0°F (1977) | 45.0°F (1967) | 0.85 in (1974) |
| September 4 | 90.0°F (2018) | 51.1°F (1960) | 0.79 in (1969) |
| September 5 | 93.0°F (2023) | 50.0°F (1963) | 0.39 in (2025) |
| September 6 | 93.0°F (2023) | 48.0°F (1962) | 3.31 in (2008) |
| September 7 | 95.0°F (2023) | 46.0°F (1962) | 0.80 in (1974) |
| September 8 | 91.0°F (2015) | 44.1°F (1962) | 2.50 in (1969) |
| September 9 | 90.0°F (1959) | 46.9°F (1956) | 0.50 in (2021) |
| September 10 | 84.9°F (1961) | 42.1°F (1975) | 1.99 in (2023) |
| September 11 | 90.0°F (2013) | 45.0°F (1967) | 4.61 in (1954) |
| September 12 | 88.0°F (1952) | 42.1°F (1958) | 5.07 in (1960) |
| September 13 | 89.1°F (1952) | 43.0°F (1955) | 2.10 in (1971) |
| September 14 | 84.9°F (1961) | 42.1°F (1963) | 0.78 in (1966) |
| September 15 | 84.0°F (2021) | 42.1°F (1964) | 1.00 in (2005) |
| September 16 | 82.9°F (1957) | 42.1°F (1964) | 1.22 in (2002) |
| September 17 | 82.0°F (2015) | 39.0°F (1950) | 0.97 in (2005) |
| September 18 | 84.0°F (2021) | 37.9°F (1959) | 3.90 in (2004) |
| September 19 | 88.0°F (2024) | 41.0°F (1956) | 1.28 in (2016) |
| September 20 | 81.0°F (1955) | 42.1°F (2004) | 2.60 in (1977) |
| September 21 | 84.9°F (2016) | 35.1°F (1956) | 2.14 in (1966) |
| September 22 | 88.0°F (1970) | 37.0°F (1948) | 0.58 in (2013) |
| September 23 | 89.1°F (1970) | 37.9°F (1953) | 1.57 in (1975) |
| September 24 | 86.0°F (2017) | 37.0°F (1963) | 2.70 in (1977) |
| September 25 | 84.0°F (2010) | 34.0°F (1963) | 2.26 in (2018) |
| September 26 | 82.0°F (1958) | 39.9°F (1949) | 1.99 in (2008) |
| September 27 | 84.9°F (2017) | 36.0°F (1957) | 1.92 in (1962) |
| September 28 | 82.0°F (1948) | 34.0°F (1957) | 2.51 in (2012) |
| September 29 | 82.0°F (1959) | 36.0°F (1957) | 1.88 in (2023) |
| September 30 | 82.0°F (2025) | 36.0°F (1951) | 0.88 in (2015) |