July weather forecast
Groton, CT

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Weather in July

The heart of summer hits in July, characterized by the highest average temperatures that reach up to 78.6°F (25.9°C). Clear skies, long daylight hours, and enhanced sea temperatures make July the month prime for outdoor and water activities. Groton witnesses a substantial influx of tourists due to the warm and welcoming weather. Humidity levels slightly increase without causing substantial discomfort. The month of July truly represents the vibrant and sunny summer season of Connecticut.

Temperature

With its high average temperature of 78.6°F (25.9°C) and a low of 66.7°F (19.3°C), July is regarded as the warmest month.

Humidity

In July, the average relative humidity is 79%.

Rainfall

In Groton, in July, during 15.8 rainfall days, 2.44" (62mm) of precipitation is typically accumulated. In Groton, during the entire year, the rain falls for 159.8 days and collects up to 33.07" (840mm) of precipitation.

Snowfall

May through October are months without snowfall.

Ocean temperature

In July, the average ocean temperature in Groton is 69.4°F (20.8°C).
Note: Swimming in 69.4°F (20.8°C) is not an enjoyable experience for most. Breathing becomes progressively more challenging as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

Daylight

In Groton, the average length of the day in July is 14h and 49min.
On the first day of the month, sunrise is at 5:19 am and sunset at 8:25 pm. On the last day of July, in Groton, Connecticut, sunrise is at 5:43 am and sunset at 8:06 pm EDT.

Sunshine

The average sunshine in July is 10.5h.

UV index

The months with the highest UV index in Groton are June through August, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: The daily high UV index of 6 in July translates into this advice:
Stick with precautions and abide by sun safety procedures. Evading sunburn is essential. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.
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Frequently asked questions

What is the warmest month in Groton?

July is the warmest month of the year in Groton, registering average temperatures as high as 78.6°F (25.9°C) and as low as 66.7°F (19.3°C).

What is the average July temperature in Groton?

In July, the average high-temperature and low-temperature in Groton are 78.6°F (25.9°C) and 66.7°F (19.3°C) respectively.

What is the average humidity in July in Groton?

In July, the average relative humidity is 79%.

How many days does it rain in July in Groton?

In Groton, Connecticut, in July, during 15.8 rainfall days, 2.44" (62mm) of precipitation is typically accumulated.

When it does not snow in Groton?

In Groton, Connecticut, snow does not fall in May through October.

How cold is the water in July in Groton?

In July, the average ocean temperature in Groton is 69.4°F (20.8°C). Swimming in 69.4°F (20.8°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

What is the average length of the day in July in Groton?

In July, the average day length is 14h and 49min.

When is the sunrise / sunset in July in Groton?

In July, on the first day of the month, sunrise is at 5:19 am and sunset at 8:25 pm. On the last day of the month, sunrise is at 5:43 am and sunset at 8:06 pm EDT.

How many hours of sunshine does Groton have in July?

The average sunshine duration in July is 10.5h.

When is the highest UV index in Groton?

The months with the highest UV index are June through August, with an average maximum UV index of 6.

How high is the UV index in July in Groton?

The average daily maximum UV index in July in Groton is 6. A UV Index of 6 to 7 symbolizes a high hazard to health from unsafe exposure to Sun's UV rays.
Today
Tomorrow
Long-term
YearJFMAMJJulyASOND
Jun
July
Aug
Average high temperature
71.4°F 21.9°C
78.6°F 25.9°C
77.7°F 25.4°C
Average low temperature
59°F 15°C
66.7°F 19.3°C
66.2°F 19°C
Average pressure
29.93" 760mmHg
29.95" 761mmHg
29.98" 761mmHg
Average wind speed
8.1mph 13km/h
7.8mph 12.6km/h
7.8mph 12.6km/h
Average max. wind speed
8.8mph 14.2km/h
8.4mph 13.5km/h
8.4mph 13.5km/h
Average wind speed gusts
13.4mph 21.6km/h
12.6mph 20.3km/h
12.5mph 20.1km/h
Average humidity
80%
79%
78%
Average rainfall
2.72" 69mm
2.44" 62mm
2.36" 60mm
Average rainfall days
15
15.8
13.8
Average snowfall
0" 0mm
0" 0mm
0" 0mm
Average snowfall days
0
0
0
Average sea temperature
62°F 16.7°C
69.5°F 20.8°C
72.1°F 22.3°C
Average daylight
15h 1min
14h 5min
13h 5min
Average sunshine
9h 3min
10h 3min
10h 4min
Average sunshine days
12.8
13.4
14.6
Average UV index
6
6
6
Average cloud cover
37%
31%
29%
Average visibility
6mi 9.7km
6mi 9.7km
6mi 9.7km

Average temperature in July
Groton, CT

Average temperature in July - Groton, CT
  • Average high temperature in July: 78.6°F

The warmest month (with the highest average high temperature) is July (78.6°F).
The month with the lowest average high temperature is January (36.1°F).

  • Average low temperature in July: 66.7°F

The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).

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Average pressure in July
Groton, CT

Average pressure in July - Groton, CT
  • Average pressure in July: 29.95"Hg

The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

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Average wind speed in July
Groton, CT

Average wind speed in July - Groton, CT
  • Average wind speed in July: 7.8mph

The windiest month (with the highest average wind speed) is January (11.9mph).
The calmest months (with the lowest average wind speed) are July and August (7.8mph).

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Average humidity in July
Groton, CT

Average humidity in July - Groton, CT
  • Average humidity in July: 79%

The month with the highest relative humidity is June (80%).
The months with the lowest relative humidity are January, March, April and November (74%).

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Average rainfall in July
Groton, CT

Average rainfall in July - Groton, CT
  • Average rainfall in July: 2.44"

The wettest month (with the highest rainfall) is December (3.86").
The driest month (with the least rainfall) is September (1.65").

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Average rainfall days in July
Groton, CT

Average rainfall days in July - Groton, CT
  • Average rainfall days in July: 15.8 days

The month with the highest number of rainy days is July (15.8 days).
The month with the least rainy days is February (9.5 days).

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Average snowfall in July
Groton, CT

Average snowfall in July - Groton, CT
  • Average snowfall in July: 0"

The month with the highest snowfall is March (2.56").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in July
Groton, CT

Average snowfall days in July - Groton, CT
  • Average snowfall days in July: 0 days

The month with the highest number of snowfall days is February (6.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

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Average sea temperature in July
Groton, CT

Average sea temperature in July - Groton, CT
  • Average sea temperature in July: 69.5°F

The best month for swimming (with the highest average sea temperature) is August (72.1°F).
The coldest month (with the lowest average sea temperature) is February (38.8°F).

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Average daylight in July /
Average sunshine in July
Groton, CT

Average daylight in July / Average sunshine in July - Groton, CT
  • Average daylight in July: 14h and 5min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in July: 10h and 3min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 54min).

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Average sunshine days in July
Groton, CT

Average sunshine days in July - Groton, CT
  • Average sunshine days in July: 13.4 days

The month with the most sunshine days is November (16.5 days).
The month with the least sunshine days is February (12.5 days).

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Average UV index in July
Groton, CT

Average UV index in July - Groton, CT
  • Average UV index in July: 6

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).

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Average cloud cover in July
Groton, CT

Average cloud cover in July - Groton, CT
  • Average cloud cover in July: 31

The months with the most cloud cover are February, March and December (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 29).

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Average visibility in July
Groton, CT

Average visibility in July - Groton, CT
  • Average visibility in July: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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Groton, Connecticut, USA

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