August weather in Groton, CT
The average temperature in Groton in August is 71.5°F (63.8°F–79.2°F). Average precipitation: 3.32 inches.
August is a summer month in Groton, and is warmer than the annual average of 51.4°F. Daily temperatures swing about 15.4°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 13h 40m. For travel, August is one of the best months of the year to visit.
Avg High
79.2°F
Avg Low
63.8°F
Precipitation
3.32 in
Daylight
13h 40m
August records in Groton
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 90.0°F (2007) | 54.0°F (2021) | 0.42 in (2003) |
| August 2 | 91.9°F (2006) | 57.0°F (2023) | 0.16 in (2008) |
| August 3 | 90.0°F (2006) | 57.9°F (2021) | 0.51 in (2006) |
| August 4 | 84.9°F (2004) | 57.0°F (2013) | 1.73 in (2018) |
| August 5 | 89.1°F (2018) | 57.0°F (2013) | 1.57 in (2004) |
| August 6 | 88.0°F (2010) | 53.1°F (2013) | 1.18 in (2008) |
| August 7 | 88.0°F (2022) | 52.0°F (2004) | 1.46 in (2000) |
| August 8 | 95.0°F (2025) | 54.0°F (2004) | 0.98 in (2003) |
| August 9 | 91.0°F (2022) | 55.9°F (2014) | 0.42 in (2013) |
| August 10 | 91.0°F (2005) | 55.0°F (2007) | 1.11 in (2016) |
| August 11 | 88.0°F (2005) | 53.1°F (2007) | 0.91 in (2015) |
| August 12 | 88.0°F (2021) | 54.0°F (2006) | 0.51 in (2023) |
| August 13 | 90.0°F (2016) | 50.0°F (2006) | 2.40 in (2014) |
| August 14 | 93.0°F (2016) | 54.0°F (2006) | 1.06 in (2011) |
| August 15 | 90.0°F (2016) | 51.1°F (2013) | 2.61 in (2011) |
| August 16 | 87.1°F (2017) | 51.1°F (2014) | 0.38 in (2020) |
| August 17 | 90.0°F (2002) | 54.0°F (2000) | 0.60 in (2003) |
| August 18 | 87.1°F (2009) | 53.1°F (2000) | 1.47 in (2024) |
| August 19 | 87.1°F (2002) | 51.1°F (2007) | 0.46 in (2024) |
| August 20 | 88.0°F (2019) | 48.9°F (2008) | 1.58 in (2025) |
| August 21 | 87.1°F (2005) | 46.9°F (2000) | 0.85 in (2004) |
| August 22 | 87.1°F (2019) | 52.0°F (2000) | 1.40 in (2022) |
| August 23 | 84.0°F (2017) | 53.1°F (2004) | 0.43 in (2022) |
| August 24 | 84.0°F (2022) | 50.0°F (2003) | 0.46 in (2015) |
| August 25 | 88.0°F (2022) | 52.0°F (2004) | 0.75 in (2006) |
| August 26 | 100.9°F (2000) | 50.0°F (2004) | 0.34 in (2013) |
| August 27 | 89.1°F (2000) | 53.1°F (2008) | 0.53 in (2006) |
| August 28 | 89.1°F (2000) | 46.0°F (2025) | 3.24 in (2006) |
| August 29 | 91.9°F (2016) | 54.0°F (2003) | 1.87 in (2002) |
| August 30 | 91.0°F (2010) | 51.1°F (2012) | 0.99 in (2005) |
| August 31 | 91.0°F (2010) | 48.0°F (2025) | 1.34 in (2004) |