September weather in New London, CT
The average temperature in New London in September is 65.2°F (56.9°F–73.5°F). Average precipitation: 3.83 inches.
September is a fall month in New London, and is warmer than the annual average of 51.4°F. Daily temperatures swing about 16.6°F between overnight low and afternoon high. Expect about 9 days with precipitation. Daylight averages about 12h 16m. For travel, September is one of the best months of the year to visit.
Avg High
73.5°F
Avg Low
56.9°F
Precipitation
3.83 in
Daylight
12h 16m
September records in New London
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 89.1°F (2010) | 48.9°F (2017) | 1.59 in (2021) |
| September 2 | 87.1°F (2010) | 45.0°F (2017) | 2.05 in (2021) |
| September 3 | 87.1°F (2020) | 48.0°F (2024) | 1.57 in (2010) |
| September 4 | 90.0°F (2018) | 48.9°F (2024) | 0.88 in (2000) |
| September 5 | 89.1°F (2023) | 48.0°F (2000) | 1.70 in (2022) |
| September 6 | 90.0°F (2023) | 46.9°F (2000) | 2.75 in (2008) |
| September 7 | 89.1°F (2023) | 46.0°F (2000) | 1.05 in (2011) |
| September 8 | 86.0°F (2015) | 48.0°F (2025) | 2.11 in (2011) |
| September 9 | 88.0°F (2016) | 46.9°F (2013) | 0.64 in (2021) |
| September 10 | 84.0°F (2023) | 46.0°F (2003) | 2.71 in (2015) |
| September 11 | 87.1°F (2013) | 46.9°F (2006) | 0.71 in (2009) |
| September 12 | 82.0°F (2005) | 43.0°F (2006) | 0.76 in (2008) |
| September 13 | 87.1°F (2019) | 45.0°F (2002) | 1.63 in (2022) |
| September 14 | 82.0°F (2016) | 48.9°F (2014) | 0.37 in (2001) |
| September 15 | 82.9°F (2008) | 46.9°F (2001) | 1.54 in (2005) |
| September 16 | 80.1°F (2003) | 44.1°F (2010) | 0.79 in (2003) |
| September 17 | 79.0°F (2005) | 43.0°F (2013) | 0.83 in (2005) |
| September 18 | 81.0°F (2016) | 41.0°F (2013) | 2.24 in (2012) |
| September 19 | 81.0°F (2024) | 43.0°F (2019) | 2.19 in (2016) |
| September 20 | 80.1°F (2022) | 42.1°F (2020) | 0.15 in (2000) |
| September 21 | 84.0°F (2016) | 39.9°F (2020) | 1.43 in (2001) |
| September 22 | 81.0°F (2004) | 39.0°F (2020) | 1.05 in (2022) |
| September 23 | 86.0°F (2017) | 41.0°F (2014) | 1.01 in (2002) |
| September 24 | 82.0°F (2009) | 43.0°F (2013) | 0.64 in (2021) |
| September 25 | 82.0°F (2010) | 41.0°F (2012) | 2.21 in (2025) |
| September 26 | 78.1°F (2007) | 43.0°F (2009) | 2.01 in (2008) |
| September 27 | 80.1°F (2017) | 41.0°F (2000) | 0.94 in (2008) |
| September 28 | 81.0°F (2017) | 42.1°F (2000) | 1.75 in (2004) |
| September 29 | 78.1°F (2019) | 36.0°F (2000) | 1.68 in (2004) |
| September 30 | 77.0°F (2010) | 37.9°F (2000) | 1.60 in (2015) |