Groton Weather in May
Average highs run from 62°F on May 1 to 71°F on May 31, and lows from 46°F to 54°F. Normal precipitation for the month is 3.67 in over about 12 wet days.
May day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
May at a glance
- Average high
- 66°F
- Average low
- 50°F
- Precipitation
- 3.67 in
- Record high
- 93°FMay 31, 2022
- Record low
- 30°FMay 1, 2008
- Chance of a freeze
- 2%
- Daylight
- 14 h 00 min to 14 h 57 min
- Cloud cover
- 63%
- Humidity
- 79%
- Dew point
- 49°F
- Wind
- 5.6 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| May 1 | 62°F | 46°F | 74°F 2001 | 30°F 2008 | 39% | 0% |
| May 2 | 63°F | 46°F | 82°F 2001 | 35°F 2005 | 39% | 0% |
| May 3 | 63°F | 46°F | 79°F 2001 | 35°F 2000 | 39% | 0% |
| May 4 | 63°F | 47°F | 82°F 2001 | 35°F 2005 | 39% | 0% |
| May 5 | 63°F | 47°F | 78°F 2000 | 34°F 2003 | 39% | 0% |
| May 6 | 64°F | 47°F | 79°F 2010 | 36°F 2007 | 39% | 0% |
| May 7 | 64°F | 48°F | 79°F 2004 | 31°F 2001 | 38% | 0% |
| May 8 | 64°F | 48°F | 81°F 2000 | 33°F 2001 | 38% | 0% |
| May 9 | 65°F | 48°F | 77°F 2000 | 35°F 2020 | 38% | 0% |
| May 10 | 65°F | 48°F | 75°F 2001 | 35°F 2020 | 38% | 0% |
| May 11 | 65°F | 49°F | 80°F 2001 | 32°F 2010 | 38% | 0% |
| May 12 | 65°F | 49°F | 82°F 2023 | 39°F 2010 | 38% | 0% |
| May 13 | 66°F | 49°F | 83°F 2023 | 35°F 2005 | 38% | 0% |
| May 14 | 66°F | 49°F | 70°F 2000 | 33°F 2020 | 38% | 0% |
| May 15 | 66°F | 50°F | 74°F 2004 | 36°F 2013 | 38% | 0% |
| May 16 | 66°F | 50°F | 76°F 2004 | 36°F 2002 | 38% | 0% |
| May 17 | 67°F | 50°F | 77°F 2010 | 37°F 2003 | 38% | 0% |
| May 18 | 67°F | 50°F | 85°F 2017 | 33°F 2023 | 37% | 0% |
| May 19 | 67°F | 51°F | 85°F 2017 | 38°F 2002 | 37% | 0% |
| May 20 | 68°F | 51°F | 85°F 2026 | 38°F 2002 | 37% | 0% |
| May 21 | 68°F | 51°F | 78°F 2010 | 36°F 2020 | 37% | 0% |
| May 22 | 68°F | 52°F | 78°F 2021 | 40°F 2002 | 37% | 0% |
| May 23 | 68°F | 52°F | 88°F 2021 | 43°F 2006 | 37% | 0% |
| May 24 | 69°F | 52°F | 79°F 2024 | 43°F 2020 | 36% | 0% |
| May 25 | 69°F | 52°F | 83°F 2007 | 44°F 2006 | 36% | 0% |
| May 26 | 69°F | 53°F | 86°F 2010 | 43°F 2013 | 36% | 0% |
| May 27 | 69°F | 53°F | 83°F 2019 | 41°F 2013 | 36% | 0% |
| May 28 | 70°F | 53°F | 78°F 2007 | 43°F 2013 | 36% | 0% |
| May 29 | 70°F | 54°F | 80°F 2012 | 39°F 2014 | 35% | 0% |
| May 30 | 70°F | 54°F | 84°F 2010 | 41°F 2014 | 35% | 0% |
| May 31 | 71°F | 54°F | 93°F 2022 | 38°F 2026 | 35% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (EDT).
- May 1
- sunrise 5:46 AM, sunset 7:46 PM
- May 31
- sunrise 5:18 AM, sunset 8:15 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00063207 (Groton), public domain. Records: NOAA GHCN-Daily, station USW00014707, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.