Climate and monthly weather forecast
Connecticut, USA

Flag of Connecticut, USA
Flag of Connecticut, USA

The climate of Connecticut

Connecticut climate ranges from humid continental type (Köppen climate classification Dfa, Dfb) in the north to humid subtropical (Köppen Cfa, Cfb) in the south. Summers are hot and humid, while winters range from mild on the coast to cold and snowy in the interior. Connecticut lies in the southwestern New England region, which is the northeastern part of the United States. Rhode Island in the east, Long Island Sound in the south, New York in the west, and Massachusetts in the north border the state. The climate varies by region, and there is little influence of geographical factors other than the water bodies in the south.

Connecticut, the Constitution State, has an average elevation of 150 meters above sea level with the highest point at 725 meters on the south slope of Mount Frissell on the border. The Connecticut River nearly bisects the state before flowing into the Long Island Sound in the south. The diverse topography consists of rolling hills and farms in the north to coastal marshes and beaches in the east. Northern hardwood, conifers, oak, spruce, and maple form the majority of the forests in the state. New England-Acadian forests are rife in the northwest, while northeastern coastal forests constitute parts of the south and east.

Spring has slightly cool to warm temperatures in Connecticut, and the heat increases by the later part of the season. The Bermuda High brings hot weather conditions from May to 8register peak temperatures during July. Average high temperatures reach 85°F (29.4°C) in summer, while heat waves occasionally push temperatures above 100°F (37.8°C). Thunderstorms are frequent in late spring and summer, often accompanied by lightning and thunder. An occasional tornado invades the state in the storm season. Hurricanes rarely hit the state directly. Fall is mild to cold with colorful foliage that moves quickly from the north to the south. Winters are cold, with average low temperatures between 1°F (-17.2°C) to 3°F (-16.1°C) at the peak of January.

The rainfall in Connecticut is fairly even throughout the year and averages in the range of 44" (1118mm) to 48" (1219mm) annually. Significant differences occur in precipitation between two topographically different places just a few miles away. Snowfall averages from a yearly 20" (508mm) in the south and east, to 60" (1524mm) in the northern hilly regions. Higher elevations have recorded snowfall above 150" (3810mm) in unusually cold winter. Annual sunshine averages 2500 hours, with the sunniest period between June and August. The percentage of possible annual sunshine ranges from 45% to 65%, with 100 to 125 clear days in the year. Humidity is the lowest in the spring and highest in late summer and early fall.

Danbury recorded Connecticut's highest ever temperature of 106°F (41.1°C) on July 15, 1995, while Falls Village recorded the coldest temperature of -32°F (-35.6°C) on February 16, 1943.

The best time to visit Connecticut

The best time to visit Connecticut is from mid-May to mid-October that encompasses the period of late spring to mid-autumn. Late spring has warm temperatures with day temperatures in the 65°F (18.3°C) to 70°F (21.1°C) range. May is warm with unexpected rain as well as bright sunshine. Summers are hot and humid but rarely go past 100°F (37.8°C). The fall season has pleasant temperatures from September to early November. The peak foliage displays in the mid of October with spectacular hues in the high country. Summer crowds disperse by the beginning of September, but there are many visitors in the fall season.

The worst time to visit Connecticut

The worst time to visit Connecticut is during the winter season from December to February when the cold is at its peak. Cold fronts from the Canadian North frequently invade the state with night temperatures often dropping below 0°F (-17.8°C). Snowfall is heavy in the winter and
blizzards add to the snow depth. Wintry conditions make roads slippery with the frequent invasion of black ice. Heavy fog descends in the coastal regions during late winter. The cold season sees low footfall in Connecticut except those of snow lovers.

Weather hazards

Connecticut is prone to thunderstorms in spring and early summer. Lightning and rain often accompany the storms, with occasional casualties. Late spring is also prone to flooding with the thawing of snow and heavy rain. Snowstorms are frequent in the winter, deposit large amounts of snow, and stall everyday life for many days. Violent storms last for a while and create icy conditions with a severe drop in visibility. Fallen trees on power lines are the most common cause of power outage during such periods. Nor'easters are the most significant hazard with strong winds, heavy rainfall, and snowfall. Storms during high tide cause heavy damage along the shore.

Weather in January

January is usually the coldest and snowiest month of the year with the arrival of the New Year in Connecticut. The average temperatures are in the cold zone of 13°F (-10.6°C) to 39°F (3.9°C), with Hartford, the capital between 18°F (-7.8°C) to 35°F (1.7°C). The rainfall is moderate in the 3" (76mm) to 4" (102mm) range, but the snowfall is ample, especially in the interior of the state where it ranges from 10" (254mm) to 20" (508mm). Weather in January »

Weather in February

February is the driest month of the year in Connecticut as the cold holds the state in its sway. The precipitation drops in the range of 2" (51mm) to 3" (76mm), but the skies remain gloomy in the winter. The average temperatures statewide are in the 15°F (-9.4°C) to 42°F (5.6°C) zone with Bridgeport and New Haven registering between 25°F (-3.9°C) to 41°F (5°C). Weather in February »

Weather in March

March is cold in Connecticut, with the transition from winter to spring in the second half of the month. The average high temperatures are in the cold 45°F (7.2°C) to 50°F (10°C) range, while the average low temperatures are in the freezing zone of 22°F (-5.6°C) to 32°F (0°C). Weather in March »

Weather in April

April brings the first signs of warmth in Connecticut with the advance of the spring season. The weather is unpredictable as the rest of New England with sunny periods between patches of wet weather. Temperatures fare better during the day between 54°F (12.2°C) to 64°F (17.8°C), while the nights ascend above freezing to register in the 34°F (1.1°C) to 42°F (5.6°C). Rain is persistent during early spring and makes it mandatory to carry a rain jacket or an umbrella for outdoor visits. Weather in April »

Weather in May

May is a beautiful spring month in Connecticut with many sunny days and pleasant conditions. Late spring sees average high temperatures in the warm 65°F (18.3°C) to 73°F (22.8°C) zone and average low temperatures in the mild 44°F (6.7°C) to 50°F (10°C). The rainfall is to the tune of 3" (76mm) to 4" (102mm) but is in the form of light showers most of the time. Weather in May »

Weather in June

June is the beginning of the summer season in Connecticut, with warm temperatures amid 9 hours of daily sunshine. The days are long, but the brightest season of the year is prone to frequently moist periods. Rainfall is to the tune of 3" (76mm) to 4" (102mm), with 10 to 12 days of wet weather. Day temperatures bask in the glorious sunshine to register in the range of 73°F (22.8°C) to 81°F (27.2°C). Weather in June »

Weather in July

July is by far the hottest month of the year in Connecticut, with the average high temperatures in the 78°F (25.6°C) to 85°F (29.4°C) range. The heat is oppressive at times, particularly in inland areas like Hartford and Danbury, where the temperatures regularly cross 90°F (32.2°C). Weather in July »

Weather in August

August lies in the hot summer of Connecticut, with long periods of clear skies and sunshine. The mercury column is in the average range of 57°F (13.9°C) to 84°F (28.9°C) with long days and high humidity. Norwich and Stamford in the coastal area register slightly higher temperatures than the interior, between 61°F (16.1°C) to 84°F (28.9°C). Light to moderate showers occur in the majority of the state but rarely last for long periods. Weather in August »

Weather in September

September is the beginning of the colorful fall season in Connecticut with moderate temperatures. The average high temperatures are in the pleasant 68°F (20°C) to 76°F (24.4°C) range, while the average low temperatures are in the mild 48°F (8.9°C) to 54°F (12.2°C) zone. Weather in September »

Weather in October

October is the time of the peak fall foliage in Connecticut. Oaks, spruces, maples, and hardwoods have their distinct hues of yellow, orange, red, and gold. By mid-October, the colors move to cover the entire area from the north to the south. The average temperatures are in the mild 41°F (5°C) to warm 65°F (18.3°C), with 3" (76mm) to 5" (127mm) of rainfall in the majority of the state. Weather in October »

Weather in November

November brings the last days of the autumn season in Connecticut with a steady buildup a cold. The skies are partly cloudy, and the days are short. The daily sunshine is at the lowest of the year at less than 5 hours. The average low temperatures are in the cold 29°F (-1.7°C) to 38°F (3.3°C) range, while the average high temperatures are in the mild zone of 45°F (7.2°C) to 54°F (12.2°C). Weather in November »

Weather in December

December is the beginning of the icy winter in Connecticut, with the average temperatures in the 20°F (-6.7°C) to 44°F (6.7°C) range. Cold fronts occasionally push the temperatures below 0°F (-17.8°C) as gray skies rule the roost. Weather in December »


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