Climate and monthly weather forecastOld Greenwich, CT
Climate and monthly weather forecast
The climate of Old Greenwich
Nestled in the heart of Connecticut, USA, Old Greenwich has a Humid subtropical climate, without a dry season, indicated by its Köppen climate classification of Cfa. Falling within the temperate zone, it experiences four distinct seasons. An annual overview suggests an average high temperature ranging from 36°F (2.2°C) to 81.9°F (27.7°C) and an average low varying between 26.2°F (-3.2°C) to 69.3°F (20.7°C). The coldest temperatures occur in January and February, while the warmest months typically are July and August.Throughout the year, the relative humidity remains fairly consistent, oscillating between 71% and 75%. Rainfall is frequent in Old Greenwich, with monthly averages varying from 2.44" (62mm) to 4.13" (105mm). The most significant rainfall occurs in July, while February sees the least. Snow is predominantly a winter phenomenon, with an average snowfall ranging from 0.08" (2mm) to 2.6" (66mm) in winter months.
Sea temperatures are frequently most agreeable from June to September, rising from an average of 41.6°F (5.3°C) in January to a comfortable 73.1°F (22.8°C) in August. While daylight varies from 9.6 hours in January to 15.1 hours in June. Overall, Old Greenwich has mildly variable weather throughout the year, offering unique experiences in each season.
The best time to visit Old Greenwich
Considering the distinctive seasonal weather patterns, the best time to visit Old Greenwich largely depends on the activities one wishes to partake in. For those interested in beach activities, June to August would be ideal when the sea temperature averages between 63°F (17.2°C) and 73.1°F (22.8°C). The climate is relatively warm during these months, with an average high temperature ranging from 74.7°F (23.7°C) to 81.9°F (27.7°C).If outdoor exploration is the key agenda, September and October offer pleasant weather, with an average high temperature from 73.2°F (22.9°C) to 62.4°F (16.9°C), and reduced rainfall as compared to the summer months. Additionally, this period benefits from comparatively lower humidity levels, offering comfortable conditions for hiking or sightseeing.
The worst time to visit Old Greenwich
Despite the charm of winter wonderlands, January and February might not be the best months to visit Old Greenwich. The temperatures during these months can drop below freezing, with an average low from 26.2°F (-3.2°C) to 27.7°F (-2.4°C). Moreover, the average snowfall in these months can reach up to 2.6" (66mm), which can cause roadblocks and hinder travel plans. This, combined with reduced daylight hours could make these months less appealing to some.Spring weather in Old Greenwich
Spring, falling between March and May, welcomes the onset of warmer weather. Average high temperatures rise gradually from 45°F (7.2°C) to 65.8°F (18.8°C), while low temperatures hover between 34.2°F (1.2°C) and 53.2°F (11.8°C). Rainfall levels increase during this season, peaking in May with an average of 3.11" (79mm), and associated increase in humidity.Summer weather in Old Greenwich
June through August denotes the summer season in Old Greenwich. With an average high temperature between 74.7°F (23.7°C) and 81.9°F (27.7°C), the climate is comfortably warm. Rainfall is at its peak during these months, particularly in July where it can reach 4.13" (105mm).Autumn weather in Old Greenwich
The transition from summer to winter, the autumn season between September and November, conditions in Old Greenwich become more pleasant. With an average high temperature receding from 73.2°F (22.9°C) to 50.9°F (10.5°C) and an average low from 61.7°F (16.5°C) to 40.8°F (4.9°C), the climate is comparatively cooler. Rainfall also decreases during this period, averaging between 2.68" (68mm) and 3.46" (88mm).Winter weather in Old Greenwich
December to February marks the winter in Old Greenwich. The average high temperature drops significantly during these months, ranging between 36°F (2.2°C) and 45°F (7.2°C). While the average low runs from 26.2°F (-3.2°C) to 34.2°F (1.2°C). Snowfall is highest in these months, reaching up to 2.6" (66mm) in January and February. Consequently, temperatures decrease to create a chilly climate, thus it would only appeal to those who appreciate colder weather.Weather in January
In Old Greenwich, January is the month to bundle up, with temperatures dropping to the lowest degree of the year. Despite the long nights and cold weather, the heavily saturated air creates a unique aesthetic. Bitter winds blowing at 10mph (16.1km/h) can make the temperature feel even colder than it actually is. Weather in January »Weather in February
The weather variations from January to February in Old Greenwich are minimal, with average low and high temperatures hovering around the freezing point, and rainfall amounting to 2.48" (63mm). However, the sightings of snow tend to increase, creating a lovely winter atmosphere. Weather in February »Weather in March
As Old Greenwich moves into March, the air becomes crisper, and the days longer. The intensity of the sun's rays increases, resulting in slightly higher temperatures. The winter snow reduces gradually by this time, yet occasional flurries are not uncommon. Weather in March »Weather in April
April weather in Old Greenwich displays the unique charm of spring, with a massive temperature rise from 45°F (7.2°C) to 55.4°F (13°C). The skies seem to cry more often with the most rainfall in months at 3.15" (80mm), nurturing the budding plants. Weather in April »Weather in May
Old Greenwich revels in the heart of spring throughout May. The weather further warms up, and the nature bursts into a riot of colors, courtesy of the longer days and ample sunshine. Visually, it is a beautiful month as everything seems fresh and lively, becoming a favorite time for photographers and nature lovers. Weather in May »Weather in June
June marks the onset of summer in Old Greenwich, offering long, warm days that encourage outdoor activities. The radiant sunshine and low wind speed create a perfect blend for beach-goers. While the weather remains relatively dry, occasional breeze from the seas adds a refreshing touch to the otherwise warm climate. Weather in June »Weather in July
July, the height of summer in Old Greenwich, comes with some of the highest temperatures approaching 81.9°F (27.7°C)-and high humidity levels from 73% to 75%. Despite the heat, the city comes alive with residents flocking to beaches, thanks to the sea temperature reaching a comfortable 70.9°F (21.6°C). Weather in July »Weather in August
The weather in August is reminiscent of July, with high temperatures lingering in Old Greenwich. The sea temperature peaks at a comfortable 73.1°F (22.8°C), continuing to draw beachgoers. An undeniable benefit of summer is the long daylight hours, which maximize outdoor activities potential. Weather in August »Weather in September
September in Old Greenwich signals the transition from warm summer to mild fall, with temperatures beginning to decrease slowly. The rainfall is comparatively lower at 2.68" (68mm), making room for clear skies and a refreshing breeze. Weather in September »Weather in October
October takes Old Greenwich through the heart of fall, with noticeable changes in temperature and foliage. The cooler climate encourages residents to embrace the warmth of indoor activities, although the daylight hours remain ample for enjoying the increasingly colorful outdoors. Weather in October »Weather in November
As November rolls in, Old Greenwich begins to brace itself for the nearing winter. A significant drop in temperature, leading to a chilling low of 40.8°F (4.9°C), is a standard characteristic of Old Greenwich's November climate. Weather in November »Weather in December
Old Greenwich, in December, witnesses the return of winter, and with it colder temperatures and short days. By now, the impressive fall foliage has given way to a more monochromatic winter scene. Even though the temperatures continue to drop, the climate remains lively leading up to the winter holidays. Weather in December »Updated: Jul 19, 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, noted for its average high-temperature of 36°F (2.2°C) and an average low-temperature of 26.2°F (-3.2°C), is considered the coldest month.
January is the month with the least rainfall. Rain falls for 8.6 days and accumulates 2.44" (62mm) of precipitation.
Throughout the year, in Old Greenwich, there are 166.6 rainfall days, and 38.07" (967mm) of precipitation is accumulated.
January through April, November and December are months with snowfall.
In Old Greenwich, during the entire year, snow falls for 24.8 days and aggregates up to 9.33" (237mm) of snow.
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
February, May, June and December, with an average relative humidity of 75%, are most humid months.
The month with the most snowfall is February, when snow falls for 7.3 days and typically aggregates up to 2.6" (66mm) of snow.
With an average ocean temperature of 39.4°F (4.1°C), February is the month with the coldest seawater.
February and December, with an average of 4.7h of sunshine, are months with the least sunshine in Old 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.
May through October are months without snowfall.
The month with the longest days in Old Greenwich is June, with an average of 15h and 6min of daylight.
The months with the highest UV index are June through August, with an average maximum UV index of 6.
July registers as the month with the average highest temperatures, reaching 81.9°F (27.7°C) at its peak and 69.3°F (20.7°C) at the lowest.
The month with the most rainfall is July, when the rain falls for 17.8 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 Old Greenwich.
With an average relative humidity of 71%, August is the least humid month in Old Greenwich.
The month with the warmest seawater is August, with an average ocean temperature of 73°F (22.8°C).
December has the shortest days of the year, with an average of 9h and 18min of daylight.
Average temperature
Old Greenwich, CT
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (36°F).
The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure
Old 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:
30.09"Hg - Average pressure in December:
30.06"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed
Old Greenwich, CT
- Average wind speed in January:
10.1mph - Average wind speed in February:
9.8mph - Average wind speed in March:
9.8mph - Average wind speed in April:
9.1mph - Average wind speed in May:
7.6mph - Average wind speed in June:
7.1mph
- Average wind speed in July:
6.6mph - Average wind speed in August:
6.7mph - Average wind speed in September:
7.6mph - Average wind speed in October:
8.9mph - Average wind speed in November:
9.5mph - Average wind speed in December:
9.8mph
The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).
Average humidity
Old Greenwich, CT
The months with the highest relative humidity are February, May, June and December (75%).
The month with the lowest relative humidity is August (71%).
Average rainfall
Old Greenwich, CT
- Average rainfall in January:
2.44" - Average rainfall in February:
2.48" - Average rainfall in March:
2.95" - Average rainfall in April:
3.15" - Average rainfall in May:
3.11" - Average rainfall in June:
3.27"
- Average rainfall in July:
4.13" - Average rainfall in August:
3.46" - Average rainfall in September:
2.68" - Average rainfall in October:
3.46" - Average rainfall in November:
2.83" - Average rainfall in December:
4.09"
The wettest month (with the highest rainfall) is July (4.13").
The driest month (with the least rainfall) is January (2.44").
Average rainfall days
Old Greenwich, CT
- Average rainfall days in January:
8.6 days - Average rainfall days in February:
10.8 days - Average rainfall days in March:
13.2 days - Average rainfall days in April:
15.9 days - Average rainfall days in May:
17.4 days - Average rainfall days in June:
16.9 days
- Average rainfall days in July:
17.8 days - Average rainfall days in August:
16.3 days - Average rainfall days in September:
13.3 days - Average rainfall days in October:
13.7 days - Average rainfall days in November:
10.3 days - Average rainfall days in December:
12.4 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is January (8.6 days).
Average snowfall
Old Greenwich, CT
The month with the highest snowfall is February (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Old Greenwich, CT
- Average snowfall days in January:
7.1 days - Average snowfall days in February:
7.3 days - Average snowfall days in March:
4.6 days - Average snowfall days in April:
0.3 days - Average snowfall days in May:
0 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:
1.1 days - Average snowfall days in December:
4.4 days
The month with the highest number of snowfall days is February (7.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature
Old 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
Old 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 12min - 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 42min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The months with the least sunshine are February and December (Average sunshine: 4h and 42min).
Average sunshine days
Old Greenwich, CT
- Average sunshine days in January:
17.1 days - Average sunshine days in February:
13.1 days - Average sunshine days in March:
13.6 days - Average sunshine days in April:
12.2 days - Average sunshine days in May:
11.7 days - Average sunshine days in June:
11.1 days
- Average sunshine days in July:
11.3 days - Average sunshine days in August:
12 days - Average sunshine days in September:
14.8 days - Average sunshine days in October:
15.2 days - Average sunshine days in November:
17.9 days - Average sunshine days in December:
14.8 days
The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is June (11.1 days).
Average UV index
Old 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
Old 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
Old 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).
