Climate and monthly weather forecastGreenwich, CT
Climate and monthly weather forecast
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 »Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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.
The months with the least rainfall are January and February Rain falls for 7.9 days and accumulates 2.4" (61mm) of rain.
Throughout the year, there are 165.6 rainfall days, and 37.64" (956mm) of precipitation is accumulated.
January through April, November and December are months with snowfall in Greenwich.
In Greenwich, Connecticut, during the entire year, snow falls for 25.5 days and aggregates up to 8.78" (223mm) of snow.
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.
February, May and December, with an average relative humidity of 75%, are most humid months 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.
February is the month with the coldest seawater in Greenwich, with an average ocean temperature of 39.4°F (4.1°C).
With an average of 4.7h of sunshine, February has the least sunshine of the year in Greenwich, Connecticut.
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.
In Greenwich, snow does not fall in May through October.
With an average of 15h and 6min of daylight, June has the longest days of the year in Greenwich, Connecticut.
June through August, with an average maximum UV index of 6, are months with the highest UV index in Greenwich, Connecticut.
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).
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.
With an average of 10.5h of sunshine, July has the most sunshine of the year in Greenwich.
With an average relative humidity of 71%, August is the least humid month in Greenwich, Connecticut.
August is the month with the warmest seawater in Greenwich, Connecticut, with an average ocean temperature of 73°F (22.8°C).
With an average of 9h and 18min of daylight, December has the shortest days of the year in Greenwich, Connecticut.
Average temperature
Greenwich, CT
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).
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 in January:
30.05"Hg - Average pressure in February:
30.03"Hg - Average pressure in March:
30.05"Hg - Average pressure in April:
29.98"Hg - Average pressure in May:
30.01"Hg - Average pressure in June:
29.93"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.05"Hg - Average pressure in October:
30.02"Hg - Average pressure in November:
30.1"Hg - Average pressure in December:
30.06"Hg
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 in January:
9.9mph - Average wind speed in February:
9.6mph - Average wind speed in March:
9.7mph - Average wind speed in April:
9.1mph - Average wind speed in May:
7.5mph - Average wind speed in June:
7mph
- Average wind speed in July:
6.5mph - Average wind speed in August:
6.6mph - Average wind speed in September:
7.5mph - Average wind speed in October:
8.8mph - Average wind speed in November:
9.4mph - Average wind speed in December:
9.6mph
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
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 in January:
2.4" - Average rainfall in February:
2.4" - Average rainfall in March:
2.83" - Average rainfall in April:
3.11" - Average rainfall in May:
3.11" - Average rainfall in June:
3.27"
- Average rainfall in July:
4.13" - Average rainfall in August:
3.5" - Average rainfall in September:
2.72" - Average rainfall in October:
3.46" - Average rainfall in November:
2.83" - Average rainfall in December:
3.86"
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 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
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 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
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 in January:
9h and 36min - Average daylight in February:
10h and 42min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 30min - Average daylight in June:
15h and 6min
- Average daylight in July:
14h and 48min - Average daylight in August:
13h and 48min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 6min - Average daylight in November:
9h and 54min - Average daylight in December:
9h and 18min
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 42min - Average sunshine in March:
6h and 12min - Average sunshine in April:
8h and 12min - Average sunshine in May:
8h and 42min - Average sunshine in June:
9h and 30min
- Average sunshine in July:
10h and 30min - Average sunshine in August:
10h and 18min - Average sunshine in September:
8h and 48min - Average sunshine in October:
5h and 48min - Average sunshine in November:
5h and 36min - Average sunshine in December:
4h and 48min
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 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
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
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
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).
