Climate and monthly weather forecastGroton, MA
Climate and monthly weather forecast
Weather in January
January, like December, is another subzero cold winter month in Groton, Massachusetts, with an average temperature varying between 19.4°F (-7°C) and 31.3°F (-0.4°C). In Groton, the month of January registers the lowest temperatures, averaging 31.3°F (-0.4°C) at the peak and 19.4°F (-7°C) at the lowest. Weather in January »Weather in February
The last month of the winter, February, is a cold month in Groton, Massachusetts, with an average temperature ranging between min 19.9°F (-6.7°C) and max 34.7°F (1.5°C). The arrival of February brings an average high-temperature of a cold 34.7°F (1.5°C), subtly diverging from January's 31.3°F (-0.4°C). Weather in February »Weather in March
The first month of the spring, March, is also an icy month in Groton, Massachusetts, with an average temperature ranging between max 42.3°F (5.7°C) and min 27.5°F (-2.5°C). Groton's transition into March is marked by a minor temperature shift, moving from 34.7°F (1.5°C) in February to a still cold 42.3°F (5.7°C). Weather in March »Weather in April
April is a moderate spring month in Groton, Massachusetts, with temperature in the range of an average low of 38.1°F (3.4°C) and an average high of 55.6°F (13.1°C). April shows a rise in the average high-temperature, moving from March's cold 42.3°F (5.7°C) to a refreshing 55.6°F (13.1°C). Weather in April »Weather in May
The last month of the spring, May, is an enjoyable month in Groton, Massachusetts, with an average temperature varying between 47.8°F (8.8°C) and 67.6°F (19.8°C). As Groton transitions into May, the average high-temperature shows a change, moving from a moderate 55.6°F (13.1°C) in April to a still refreshing 67.6°F (19.8°C). Weather in May »Weather in June
June, the first month of the summer in Groton, is a warm month, with an average temperature fluctuating between 75.4°F (24.1°C) and 55.6°F (13.1°C). June's onset witnesses a minor shift in the average high-temperature, moving from a comfortable 67.6°F (19.8°C) in May to a warm 75.4°F (24.1°C). Weather in June »Weather in July
July, like June, in Groton, Massachusetts, is another warm summer month, with an average temperature ranging between max 82°F (27.8°C) and min 62.2°F (16.8°C). Temperature readings reach their annual highs in July, averaging 82°F (27.8°C) and a minimum average of 62.2°F (16.8°C). The heat index value during July is calculated to be a hot 87.8°F (31°C). Weather in July »Weather in August
August, the last month of the summer in Groton, is another warm month, with an average temperature varying between 60.4°F (15.8°C) and 80.2°F (26.8°C). Groton marks the onset of August with an average high-temperature of a still warm 80.2°F (26.8°C), subtly divergent from July's 82°F (27.8°C). Weather in August »Weather in September
The first month of the autumn, September, is also an agreeable month in Groton, Massachusetts, with an average temperature ranging between max 72.7°F (22.6°C) and min 54°F (12.2°C). With the onset of September, Groton's average high-temperature slightly adjusts, moderately receding from August's moderately hot 80.2°F (26.8°C) to a pleasant 72.7°F (22.6°C). Weather in September »Weather in October
October, like September, is another refreshing autumn month in Groton, Massachusetts, with an average temperature ranging between min 44.6°F (7°C) and max 59.9°F (15.5°C). The move into October indicates a reduction in the average high-temperature, down from September's pleasant 72.7°F (22.6°C) to a mild 59.9°F (15.5°C). Weather in October »Weather in November
The last month of the autumn, November, is another chilly month in Groton, Massachusetts, with temperature in the range of an average high of 47.3°F (8.5°C) and an average low of 34.3°F (1.3°C). November's arrival comes with a decrease in the average high-temperature, moving from a refreshing 59.9°F (15.5°C) in October to a frosty 47.3°F (8.5°C). Weather in November »Weather in December
The first month of the winter, December, is still a cold month in Groton, Massachusetts, with temperature in the range of an average low of 26.2°F (-3.2°C) and an average high of 37.4°F (3°C). Groton's December weather features a mild decline in high-temperatures, reducing from a chilly 47.3°F (8.5°C) in November to a wintry 37.4°F (3°C). Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Groton, MA
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (31.3°F).
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (19.4°F).
Average pressure
Groton, MA
- Average pressure in January:
30.01"Hg - Average pressure in February:
29.99"Hg - Average pressure in March:
30.03"Hg - Average pressure in April:
29.97"Hg - Average pressure in May:
30"Hg - Average pressure in June:
29.92"Hg
- Average pressure in July:
29.94"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.05"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.07"Hg - Average pressure in December:
30.04"Hg
The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed
Groton, MA
- Average wind speed in January:
8.4mph - Average wind speed in February:
8.2mph - Average wind speed in March:
8.1mph - Average wind speed in April:
7.8mph - Average wind speed in May:
6.5mph - Average wind speed in June:
6mph
- Average wind speed in July:
5.5mph - Average wind speed in August:
5.4mph - Average wind speed in September:
5.7mph - Average wind speed in October:
6.9mph - Average wind speed in November:
7.3mph - Average wind speed in December:
8mph
The windiest month (with the highest average wind speed) is January (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity
Groton, MA
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is April (71%).
Average rainfall
Groton, MA
- Average rainfall in January:
2.13" - Average rainfall in February:
2.09" - Average rainfall in March:
2.48" - Average rainfall in April:
2.64" - Average rainfall in May:
2.09" - Average rainfall in June:
2.32"
The wettest month (with the highest rainfall) is December (2.8").
The driest month (with the least rainfall) is September (1.3").
Average rainfall days
Groton, MA
- Average rainfall days in January:
7.8 days - Average rainfall days in February:
7.7 days - Average rainfall days in March:
11.4 days - Average rainfall days in April:
14.5 days - Average rainfall days in May:
15.5 days - Average rainfall days in June:
14.6 days
- Average rainfall days in July:
14.5 days - Average rainfall days in August:
13.2 days - Average rainfall days in September:
9.9 days - Average rainfall days in October:
13.5 days - Average rainfall days in November:
9.9 days - Average rainfall days in December:
9.7 days
The month with the highest number of rainy days is May (15.5 days).
The month with the least rainy days is February (7.7 days).
Average snowfall
Groton, MA
- Average snowfall in January:
4.25" - Average snowfall in February:
6.3" - Average snowfall in March:
4.76" - Average snowfall in April:
1.69" - Average snowfall in May:
0.12" - Average snowfall in June:
0"
The month with the highest snowfall is February (6.3").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Groton, MA
- Average snowfall days in January:
8.1 days - Average snowfall days in February:
7.8 days - Average snowfall days in March:
7.6 days - Average snowfall days in April:
1.6 days - Average snowfall days in May:
0.1 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.3 days - Average snowfall days in November:
1.8 days - Average snowfall days in December:
5.3 days
The month with the highest number of snowfall days is January (8.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Groton, MA
- Average daylight in January:
9h and 30min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 36min - Average daylight in June:
15h and 18min
- Average daylight in July:
14h and 54min - Average daylight in August:
13h and 54min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 48min - Average daylight in December:
9h and 6min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in January:
5h and 6min - Average sunshine in February:
4h and 36min - Average sunshine in March:
5h and 48min - Average sunshine in April:
8h and 6min - Average sunshine in May:
8h and 24min - Average sunshine in June:
9h and 0min
- Average sunshine in July:
10h and 12min - Average sunshine in August:
10h and 18min - Average sunshine in September:
8h and 18min - Average sunshine in October:
5h and 54min - Average sunshine in November:
5h and 30min - Average sunshine in December:
4h and 54min
The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days
Groton, MA
- Average sunshine days in January:
17.9 days - Average sunshine days in February:
14.5 days - Average sunshine days in March:
14.9 days - Average sunshine days in April:
13.6 days - Average sunshine days in May:
13.5 days - Average sunshine days in June:
14 days
- Average sunshine days in July:
14.6 days - Average sunshine days in August:
16.4 days - Average sunshine days in September:
17.7 days - Average sunshine days in October:
15.3 days - Average sunshine days in November:
18.4 days - Average sunshine days in December:
17.7 days
The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is May (13.5 days).
Average UV index
Groton, MA
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover
Groton, MA
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility
Groton, MA
The months with the highest visibility are April, October, November and December (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August and September (5mi).





