Average annual temperature is 11.9 °C
Absolute maximum temperature: 30.6 °C
Absolute minimum temperature: -20.9 °C
Number of sunny days: 170 days
Number of rainy days: 192 days
Number of snow days: 3 days
Look at detailed online map of Groton
* Weather data for Groton United States is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 14.8 | 18.2 | 12.7 | 25.4 | 25.7 | 24.8 | 29.5 | 27.7 | 30.6 | 24.8 | 16.9 | 15.2 |
| Average daytime temperature (°C) | 7.3 | 6.5 | 8.3 | 14.4 | 18.6 | 21.9 | 26.5 | 24.9 | 22.3 | 18.3 | 10.3 | 8.5 |
| Average temperature (°C) | 4.0 | 2.4 | 4.3 | 10.4 | 14.1 | 17.8 | 22.9 | 21.3 | 18.8 | 14.2 | 6.2 | 5.2 |
| Average night temperature (°C) | 1.2 | -1.5 | 0.6 | 6.7 | 9.6 | 14.1 | 19.8 | 18.0 | 15.8 | 11.0 | 2.5 | 2.2 |
| Absolute minimum temperature (°C) | -3.8 | -20.9 | -3.2 | -0.6 | 4.2 | 7.6 | 15.6 | 13.8 | 9.5 | 6.0 | -3.7 | -5.9 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 15.0 | 15.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 |
| Daylight mean duration (h) | 9.6 | 10.6 | 11.9 | 13.3 | 14.5 | 15.1 | 14.8 | 13.8 | 12.5 | 11.1 | 9.9 | 9.2 |
| Daylight minimum duration (h) | 9.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 | 13.0 | 11.0 | 10.0 | 9.0 | 9.0 |
| Sunshine mean duration (h) | 4.0 | 6.6 | 7.6 | 8.7 | 12.1 | 10.9 | 11.1 | 10.0 | 7.7 | 8.2 | 7.2 | 5.6 |
| Precipitation (mm) | 163 | 50 | 105 | 90 | 69 | 63 | 151 | 120 | 229 | 69 | 37 | 201 |
| Sunny days | 8 | 13 | 15 | 16 | 22 | 11 | 10 | 9 | 13 | 16 | 21 | 16 |
| Rainy days | 22 | 13 | 16 | 14 | 9 | 19 | 21 | 22 | 17 | 15 | 9 | 15 |
| Snow days | 1 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
The best time to visit Groton during the most sunny months:
The largest precipitation sum in Groton is at