Climate and monthly weather forecast
Greenwich, CT

Year J F M A M J J A S O N D

°Celsius °Fahrenheit

The straight road of North Street cutting through the green leafy suburbs of the scenic Greenwich City in Connecticut

The climate of Greenwich

Greenwich, Connecticut, lies within a climate zone classified as Cfa according to the Köppen Climate Classification. This designates it as a humid subtropical region with no pronounced dry season. Geographically, Greenwich's proximity to the Atlantic Ocean has a profound effect on its climate due to the ocean's moderating influence.

The year in Greenwich sees a significant range of temperature, which fluctuates from an average low of 26.1°F (-3.3°C) in January to the year's average high of 82°F (27.8°C) in July. The warm period lasts from June to September with comfortable temperatures ranging from 73.4°F (23°C) to 80.6°F (27°C). The cold stretch extends from December through March with temperatures dipping to a chilly 35.8°F (2.1°C) to 41.9°F (5.5°C).

The humidity remains relatively constant throughout the year, hovering around the 72% to 75% mark. Residents and visitors alike should anticipate these levels of humidity that can change the "feel" of actual temperatures, especially during the warmer months. Greenwich also experiences fluctuating rainfall levels from February to August, where measurements range from 2.4" (61mm) to 4.13" (105mm), while snowfall occurs predominantly in December and January, recording measurements of 1.97" (50mm) and 2.52" (64mm), respectively.

The best time to visit Greenwich

The optimum time to visit Greenwich would be from late spring to early fall, specifically between May and September. During this period, the temperatures are comfortable and range from 66.2°F (19°C) up to 80.6°F (27°C). These months also have substantial daylight hours, peaking at 15.1 hours in June. However, potential visitors should note that these months also have the highest rainfall measurements, peaking at 4.13" (105mm) in July, which might require occasional indoor activities.

The worst time to visit Greenwich

From a comfort point of view, the least ideal time to visit Greenwich lies between December and February. During these months, temperatures plummet to a chilly average low of 26.1°F (-3.3°C) in January and a high of only 38.3°F (3.5°C) in February. Despite its lower rainfall, these months record the highest snowfall figures in the year, with January's snowfall measuring around 1.97" (50mm). Limited daylight, with just 9.6 hours in December, might further detract from the visitor experience.

Spring weather in Greenwich

Springtime in Greenwich, lasting from March to May, heralds a gradual rise in temperatures. March starts with a cool 45°F (7.2°C), but by May, temperatures would have soared to a comfortable 66.2°F (19°C). The hours of daylight per day significantly increase from 12 hours in March to 14.5 hours in May. Spring months also experience an increase in rainfall, culminating in an average of 3.11" (79mm) falling in May.

Summer weather in Greenwich

Summer, extending from June to August, unfolds as the warmest period in Greenwich. The average high in this season soars to a peak of 82°F (27.8°C) in July, while the average low temperature hovers around 69.1°F (20.6°C). Despite recording the highest rainfall of the year, with 4.13" (105mm) in July, the ample average sunshine hours (peaking at 10.5 hours in July) and a relative humidity of around 73% make these months ideal for outdoor activities.

Autumn weather in Greenwich

The Autumn season kickstarts in September, carrying on until November. During this period, temperatures start to decline from a mild 73.4°F (23°C) in September to a cooler 50.9°F (10.5°C) in November. Rainfall in this season also decreases, reaching a year-low of 2.72" (69mm) in September. Autumn in Greenwich is also graced by moderate daylight hours, declining from 12.5 hours in September to 9.9 hours by November.

Winter weather in Greenwich

The chill of winter engulfs Greenwich in December and persists until February. The temperatures during this period can prove quite harsh, especially in January where the average low is 26.1°F (-3.3°C). The average high also remains relatively low, peaking at only 38.3°F (3.5°C) in February. Conditions are such that it leads to snowfall, accumulating to 2.52" (64mm) in February. Despite the winter chill, the relative humidity remains steady and sunshine hours range from 4.8 to 5 hours per day.

Weather in January

January bustles with the chill of winter in Greenwich, Connecticut, USA. The mountainscape appears stunning under the blanket of snow, adding to the city's winter charm. Notably, the lowest temperature records fall between 26.1°F (-3.3°C) to 35.8°F (2.1°C), indicating a frosty ambiance. Weather in January »

Weather in February

As Greenwich transitions from January to February, the city witnesses marginal climatic changes. The snow continues to mark its presence, making the city a haven for snow lovers. February holds the record for the highest snowfall of the year, measuring from 2.52" (64mm). Weather in February »

Weather in March

March brings a sigh of relief from the freezing temperatures. Although remnants of winter are still felt, signs of the spring season start appearing across Greenwich. The mercury level gradually rises from the freezing point, marking the arrival of warmer days. Weather in March »

Weather in April

April signifies the awaited arrival of spring in Greenwich. The landscape transitions from white to color, blessed with the blossoms of the season. The spectrum of temperature swings between 43.5°F (6.4°C) and 55.4°F (13°C), making it a comfortable month for outdoor exploration. Weather in April »

Weather in May

May witnesses a definitive spike in temperature, bringing warmer days to Greenwich. Relishing the sunlight becomes a common sight as the city gears towards summer. May boasts the maximum daylight hours, reaching up to 14.5 hours, ensuring the city stays active for longer. Weather in May »

Weather in June

In June, Greenwich embraces the full spectrum of summer with longer, sunnier days. The sea temperature rises to a pleasant 63°F (17.2°C), enhancing the appeal of beach visits. Amid the warmth of the summer sun, various outdoor events uplift the city's vibrant charm. Weather in June »

Weather in July

July stands as the warmest month in Greenwich with temperatures peaking up to 82°F (27.8°C). A dip in the sea becomes enticing with the water temperature averaging around 70.9°F (21.6°C). Despite dominating sunshine, an average of 18.1 days of rainfall brings occasional respite from the summer heat. Weather in July »

Weather in August

August holds on to the summer warmth, radiating the classic New England charm. Greenwich sees regular visitors thronging the famous beaches and parks. Nevertheless, the temperature slightly decreases from July, ranging from 68.7°F (20.4°C) to 80.6°F (27°C), making it a mild summer month. Weather in August »

Weather in September

With the arrival of September, Greenwich begins its transition from summer to fall. The foliage starts to change, painting the city with hues of autumn. The temperature also drops, signaling the impending colder months. Despite a decrease from August, the 3.5" (89mm) rainfall is relatively high for September. Weather in September »

Weather in October

October brings a definitive autumn feel to Greenwich. The cityscape adorned with fall colors presents a picturesque view. With the temperature ranging from 51.8°F (11°C) to 62.4°F (16.9°C), it's the perfect time for outdoor exploits. Weather in October »

Weather in November

November in Greenwich denotes the beginning of the winter season. The city gears up for the cold with preparations visible all around. The landscape dons a stark look, with most of the leaves fallen off the trees. Snow starts making its appearance, with 0.24" (6mm) recorded on average. Weather in November »

Weather in December

December marks the height of winter in Greenwich. The entire city gets covered in the white of snow and the sparkling lights of the holiday season. With the lowest sea temperature marked at 47.1°F (8.4°C), it observes the longest nights of the year with just 9.3 hours of daylight on average. Weather in December »

Frequently asked questions

What month is the coldest in Greenwich?

January, characterized by an average high temperature of 35.8°F (2.1°C) and a low temperature of 26.1°F (-3.3°C), is generally the coldest month.

What is the driest month in Greenwich?

The months with the least rainfall are January and February Rain falls for 7.9 days and accumulates 2.4" (61mm) of rain.

How many days does it rain in Greenwich?

Throughout the year, there are 165.6 rainfall days, and 37.64" (956mm) of precipitation is accumulated.

When does it snow in Greenwich?

January through April, November and December are months with snowfall in Greenwich.

How many days does it snow in Greenwich?

In Greenwich, Connecticut, during the entire year, snow falls for 25.5 days and aggregates up to 8.78" (223mm) of snow.

What are the months with the lowest UV index in Greenwich?

The months with the lowest UV index in Greenwich, Connecticut, are January through March, November and December, with an average maximum UV index of 2.

What are the most humid months in Greenwich?

February, May and December, with an average relative humidity of 75%, are most humid months in Greenwich.

When does it snow the most in Greenwich?

The month with the most snowfall is February, when snow falls for 7.1 days and typically aggregates up to 2.52" (64mm) of snow.

What is the month with the coldest ocean in Greenwich?

February is the month with the coldest seawater in Greenwich, with an average ocean temperature of 39.4°F (4.1°C).

What is the month with the least sunshine in Greenwich?

With an average of 4.7h of sunshine, February has the least sunshine of the year in Greenwich, Connecticut.

When is Daylight Saving Time (DST) in Greenwich?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.

When it does not snow in Greenwich?

In Greenwich, snow does not fall in May through October.

When are the longest days in Greenwich?

With an average of 15h and 6min of daylight, June has the longest days of the year in Greenwich, Connecticut.

What is the month with the highest UV index in Greenwich?

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

What part of the year is the hottest in Greenwich?

The highest temperatures in Greenwich are recorded in July, with averages reaching a high of 82°F (27.8°C) and a low of 69.1°F (20.6°C).

What is the wettest month in Greenwich?

The month with the most rainfall in Greenwich is July, when the rain falls for 18.1 days and typically aggregates up to 4.13" (105mm) of precipitation.

What month has the most sunshine in Greenwich?

With an average of 10.5h of sunshine, July has the most sunshine of the year in Greenwich.

What is the least humid month in Greenwich?

With an average relative humidity of 71%, August is the least humid month in Greenwich, Connecticut.

When is the ocean warmest in Greenwich?

August is the month with the warmest seawater in Greenwich, Connecticut, with an average ocean temperature of 73°F (22.8°C).

What is the month with the shortest days in Greenwich?

With an average of 9h and 18min of daylight, December has the shortest days of the year in Greenwich, Connecticut.

Year J F M A M J J A S O N D

Average temperature
Greenwich, CT

Average temperature - Greenwich, CT

Average high temperature in January:
35.8°F
Average high temperature in February:
38.3°F
Average high temperature in March:
45°F
Average high temperature in April:
55.4°F
Average high temperature in May:
66.2°F
Average high temperature in June:
74.7°F

Average high temperature in July:
82°F
Average high temperature in August:
80.6°F
Average high temperature in September:
73.4°F
Average high temperature in October:
62.4°F
Average high temperature in November:
50.9°F
Average high temperature in December:
41.9°F

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (35.8°F).

Average low temperature in January:
26.1°F
Average low temperature in February:
27.7°F
Average low temperature in March:
33.8°F
Average low temperature in April:
43.5°F
Average low temperature in May:
53.1°F
Average low temperature in June:
61.5°F

Average low temperature in July:
69.1°F
Average low temperature in August:
68.7°F
Average low temperature in September:
61.7°F
Average low temperature in October:
51.8°F
Average low temperature in November:
40.6°F
Average low temperature in December:
33.3°F

The month with the highest average low temperature is July (69.1°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).

Average pressure
Greenwich, CT

Average pressure - Greenwich, CT

The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed
Greenwich, CT

Average wind speed - Greenwich, CT

The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is July (6.5mph).

Average humidity
Greenwich, CT

Average humidity - Greenwich, CT

The months with the highest relative humidity are February, May and December (75%).
The month with the lowest relative humidity is August (71%).

Average rainfall
Greenwich, CT

Average rainfall - Greenwich, CT

The wettest month (with the highest rainfall) is July (4.13").
The driest months (with the least rainfall) are January and February (2.4").

Average rainfall days
Greenwich, CT

Average rainfall days - Greenwich, CT

Average rainfall days in January:
7.9 days
Average rainfall days in February:
10.5 days
Average rainfall days in March:
12.8 days
Average rainfall days in April:
15.5 days
Average rainfall days in May:
17.5 days
Average rainfall days in June:
17 days

Average rainfall days in July:
18.1 days
Average rainfall days in August:
16.8 days
Average rainfall days in September:
13.5 days
Average rainfall days in October:
13.8 days
Average rainfall days in November:
10.2 days
Average rainfall days in December:
12 days

The month with the highest number of rainy days is July (18.1 days).
The month with the least rainy days is January (7.9 days).

Average snowfall
Greenwich, CT

Average snowfall - Greenwich, CT

The month with the highest snowfall is February (2.52").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days
Greenwich, CT

Average snowfall days - Greenwich, CT

Average snowfall days in January:
7.2 days
Average snowfall days in February:
7.1 days
Average snowfall days in March:
5 days
Average snowfall days in April:
0.5 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 days
Average snowfall days in November:
1 days
Average snowfall days in December:
4.6 days

The month with the highest number of snowfall days is January (7.2 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average sea temperature
Greenwich, CT

Average sea temperature - Greenwich, CT

Average sea temperature in January:
41.6°F
Average sea temperature in February:
39.5°F
Average sea temperature in March:
39.7°F
Average sea temperature in April:
44.3°F
Average sea temperature in May:
51.4°F
Average sea temperature in June:
63°F

Average sea temperature in July:
70.9°F
Average sea temperature in August:
73.1°F
Average sea temperature in September:
68.9°F
Average sea temperature in October:
62.2°F
Average sea temperature in November:
53.8°F
Average sea temperature in December:
47.1°F

The best month for swimming (with the highest average sea temperature) is August (73.1°F).
The coldest month (with the lowest average sea temperature) is February (39.5°F).

Average daylight / Average sunshine
Greenwich, CT

Average daylight / Average sunshine - Greenwich, CT

Average daylight in January:
9h and 4min
Average daylight in February:
10h and 4min
Average daylight in March:
12h and 0min
Average daylight in April:
13h and 2min
Average daylight in May:
14h and 3min
Average daylight in June:
15h and 1min

Average daylight in July:
14h and 5min
Average daylight in August:
13h and 5min
Average daylight in September:
12h and 3min
Average daylight in October:
11h and 1min
Average daylight in November:
9h and 5min
Average daylight in December:
9h and 2min

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 18min).

Average sunshine in January:
5h and 0min
Average sunshine in February:
4h and 4min
Average sunshine in March:
6h and 1min
Average sunshine in April:
8h and 1min
Average sunshine in May:
8h and 4min
Average sunshine in June:
9h and 3min

Average sunshine in July:
10h and 3min
Average sunshine in August:
10h and 2min
Average sunshine in September:
8h and 5min
Average sunshine in October:
5h and 5min
Average sunshine in November:
5h and 4min
Average sunshine in December:
4h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days
Greenwich, CT

Average sunshine days - Greenwich, CT

Average sunshine days in January:
17.6 days
Average sunshine days in February:
13.5 days
Average sunshine days in March:
14 days
Average sunshine days in April:
12.7 days
Average sunshine days in May:
11.5 days
Average sunshine days in June:
10.7 days

Average sunshine days in July:
11.1 days
Average sunshine days in August:
11.8 days
Average sunshine days in September:
14.3 days
Average sunshine days in October:
15 days
Average sunshine days in November:
17.8 days
Average sunshine days in December:
15.2 days

The month with the most sunshine days is November (17.8 days).
The month with the least sunshine days is June (10.7 days).

Average UV index
Greenwich, CT

Average UV index - Greenwich, CT

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
Greenwich, CT

Average cloud cover - Greenwich, CT

The month with the most cloud cover is December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 31).

Average visibility
Greenwich, CT

Average visibility - Greenwich, CT

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).

Greenwich, Connecticut, USA

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