Climate and monthly weather forecastNew Haven, CT

Climate and monthly weather forecast
The climate of New Haven
New Haven, Connecticut, is characterized by a humid subtropical climate. Categorization under the Köppen climate classification designates a continuous presence of moisture, with no distinct dry season. This geographical positioning bestows upon New Haven a wide range of weather experiences across the seasonal spectrum.Throughout the year, the city witnesses noticeable fluctuations in climatological parameters. Temperature oscillations occur, ranging from the chilliest lows of 25.5°F (-3.6°C) in January, to sweltering peaks of 80.4°F (26.9°C) in July. These oscillations extend over to humidity levels, although less characterized, they hover around mid-70 figures across the year. Rainfall varies to a certain degree from February and November as drier periods with 2.4in, upward, reaching a climax in December with 3.86in. Conjoined to this, the amount of rainfall days ranges from as low as 9.4 days in January to a maximum of 18 days in July.
The prevalence of unique weather patterns is most pronounced in snowfall; January and February see the most snow accumulation with 2.13in and 2.68in respectively, snowfall substantially declines afterwards, with virtually none from May to November. Sea temperatures, influenced by the overall weather trend, start from lows of 38.5°F (3.6°C) in February, before peaking at 73°F (22.8°C) in August.
The best time to visit New Haven
The ideal conditions conducive for a visit to New Haven are undoubtedly between May and October. During this period, the city basks in moderate temperatures which fluctuate from 65.1°F (18.4°C) to a comfortable 80.4°F (26.9°C). The sea temperature during this period is also invitingly warm, reaching a peak of 73°F (22.8°C) in August. Besides, visitors will be able to enjoy longer daylight hours, which peak at 15.1h in June. Moreover, the sunshine hours are also the highest between these months, indicating fewer occurrences of cloudy conditions. Nevertheless, it is noteworthy that although July holds the record for the highest average temperatures, it also records the most rain-heavy days.The worst time to visit New Haven
The least favorable period to visit New Haven extends from late November to early March. Cold temperatures predominate this timeframe, with lows plunging to 25.5°F (-3.6°C) in January and barely rising beyond 43.9°F (6.6°C) in March. Snowfall during these months is experienced quite frequently with January leading with 6.1 snow days on average. Sea temperatures during this period are cold, dropping to a chilly 38.5°F (3.6°C) in February. Days are also shorter, with the least daily sunlight hours occurring in December, lasting for just 9.2h.Spring weather in New Haven
Spring in New Haven is characterized by a progressive warming trend. Temperatures begin to climb from an average low of 25.5°F (-3.6°C) in March to a pleasant high of 65.1°F (18.4°C) by May. April marks the departure from snowfall, with a meager 0.08in recorded. Rainfall also takes an upward swing, going from 2.8in in March, culminating in a slightly wetter May with 2.76in. Daylight increases significantly during this period, adding approximately two minutes per day from March to May, resulting in a daylight peak of 14.5h.Summer weather in New Haven
Summer provides New Haven with its warmest conditions. The months from June to August register high temperatures, with July being the hottest month boasting an average peak of 80.4°F (26.9°C). Rainfall during the summer months is fairly consistent, with a slight increase registered in July at 3.43in. Sea temperatures are at their most enticing from June to August, easily reaching a high of 73°F (22.8°C) in August. The summer season also graces New Haven with abundant sunshine, having as high as 15.1 sunshine hours per day in June.Autumn weather in New Haven
During Autumn, New Haven experiences a gradual cooling pattern. September sees average highs of 72.5°F (22.5°C), which decrease to an average high of 50.7°F (10.4°C) by November. This period also registers moderate to high rainfall, with the peak recorded at 3.54in in October. However, it is notable that in terms of daylight and sunshine hours, Autumn still holds appealing conditions with around 11 sunshine hours per day in September.Winter weather in New Haven
Winter ushers in the coldest period for New Haven, characterized by a significant drop in temperatures. From December to February, temperatures plummet, from a high of 41.7°F (5.4°C) in December, dropping to an average low of 26.6°F (-3°C) in February. Cold sea temperatures accompany the winter chill, sinking to 38.5°F (3.6°C) in February. Snow becomes a prevalent feature of the weather scenery in December through February, with January having the highest snowfall at 2.13in. Remarkably, despite the cold conditions, winter in New Haven possesses moderate sunshine hours with 4.8h per day in December, indicating fewer cloudy days.Weather in January
During January, New Haven experiences cold winter days, typified by the blanket of snow decorating the city with an average of 2.13" (54mm) of snowfall. Marked by a drop in temperature from the relaxing autumn climate, the chill in the air is heightened by the wind, making it slightly cooler yet crisp. Weather in January »Weather in February
Transitioning from January, the nip in the air persists, and New Haven witnesses its last snow of the winter. The snowfall inches up to 2.68" (68mm) and adds to the winter holiday charm. The bitter cold of January sees some respite. Weather in February »Weather in March
As New Haven moves into March, the weather shows signs of gradual warming. Compared to the prior month, March is warmer with an appreciable increase in daylight hours, indicating towards the approach of spring season. Scarce snowfalls are replaced by rainfall as the primary form of precipitation, making the city gleam anew. Weather in March »Weather in April
April brings significant transformations in New Haven's weather. It is devoid of snowfall with the temperature rising to a pleasant range. The cold, biting winter is becoming a memory with the emergence of sprouting buds and blossoming landscapes. Weather in April »Weather in May
New Haven in May showcases a splendid weather transformation, stepping confidently into the warm, sunny days of late spring. The city says goodbye to April’s capricious climate, firmly embracing the utilitarian weather of May, ideal for outdoor activities. Weather in May »Weather in June
June is the harbinger of summer season in New Haven with comfortable, warm temperatures gracing the city. It holds a significant increase in temperature, confirming the departure of the cool spring season. The daylight stretches out the most during this time, allowing ample sunshine to light up the city. Weather in June »Weather in July
July in New Haven marks the peak of summer, providing the highest average temperature of 80.4°F (26.9°C) and enjoying 15.1 hours of daylight. The city basks under the golden summer sun, bringing an air of laziness affecting both the locals and the visitors. Weather in July »Weather in August
August follows the trail of July's heated footsteps, but with a slight reduction in temperature. It's a serene time in New Haven when nature comes alive under the warm summer sun. Rainfall is intermittent, just enough to enhance the intense greenery of the city parks. Weather in August »Weather in September
September weather in New Haven brings a sense of transformation, triggering the advent of the autumnal breeze. Though it follows August's cue of warm days, the fall season paints the city with hues of cranberry red, pumpkin orange, and gilded gold. Weather in September »Weather in October
October in New Haven is the heart of the beautiful autumn season and the notable drop in temperature from the previous month starts setting in with characteristic chilly mornings and evenings. With the amber leaves decorating every street, the city encapsulates the essence of the fall season. Weather in October »Weather in November
November marks the transition from autumn to the early winter season in New Haven. Taking a turn from the mild weather of October, November introduces a crisp coldness that remains till the year-end. However, the luminous fall foliage against the clear, dark blue sky creates a picturesque sight, making it equally attractive. Weather in November »Weather in December
December welcomes the onset of winter in New Haven, Connecticut, USA, demonstrating temperatures as low as 32.5°F (0.3°C). Evenings turn cold earlier, marking the arrival of long winter nights. Despite its chilly attributes, locals enjoy the festivity brought in by the Christmas season. Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
New Haven, CT
The warmest month (with the highest average high temperature) is July (80.4°F).
The month with the lowest average high temperature is January (35.1°F).
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (25.5°F).
Average pressure
New Haven, CT
- Average pressure in January:
30.04"Hg - Average pressure in February:
30.02"Hg - Average pressure in March:
30.04"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:
29.95"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.05"Hg - Average pressure in October:
30.01"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
New Haven, CT
- Average wind speed in January:
10.4mph - Average wind speed in February:
10mph - Average wind speed in March:
10.1mph - Average wind speed in April:
9.4mph - Average wind speed in May:
7.8mph - Average wind speed in June:
7.1mph
- Average wind speed in July:
6.8mph - Average wind speed in August:
6.8mph - Average wind speed in September:
7.7mph - Average wind speed in October:
9.3mph - Average wind speed in November:
9.8mph - Average wind speed in December:
10.2mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity
New Haven, CT
The months with the highest relative humidity are February, May and June (76%).
The months with the lowest relative humidity are April and November (72%).
Average rainfall
New Haven, CT
- Average rainfall in January:
2.4" - Average rainfall in February:
2.4" - Average rainfall in March:
2.8" - Average rainfall in April:
3.11" - Average rainfall in May:
2.76" - Average rainfall in June:
2.95"
- Average rainfall in July:
3.43" - Average rainfall in August:
3.15" - Average rainfall in September:
2.24" - Average rainfall in October:
3.54" - Average rainfall in November:
3.07" - Average rainfall in December:
3.86"
The wettest month (with the highest rainfall) is December (3.86").
The driest month (with the least rainfall) is September (2.24").
Average rainfall days
New Haven, CT
- Average rainfall days in January:
9.4 days - Average rainfall days in February:
10.1 days - Average rainfall days in March:
12.6 days - Average rainfall days in April:
15.1 days - Average rainfall days in May:
17.2 days - Average rainfall days in June:
16.7 days
- Average rainfall days in July:
18 days - Average rainfall days in August:
17.1 days - Average rainfall days in September:
13.4 days - Average rainfall days in October:
14.3 days - Average rainfall days in November:
10.8 days - Average rainfall days in December:
12.5 days
The month with the highest number of rainy days is July (18 days).
The month with the least rainy days is January (9.4 days).
Average snowfall
New Haven, CT
The month with the highest snowfall is March (2.8").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
New Haven, CT
- Average snowfall days in January:
6.1 days - Average snowfall days in February:
7.3 days - Average snowfall days in March:
4.8 days - Average snowfall days in April:
0.4 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:
0.1 days - Average snowfall days in November:
0.8 days - Average snowfall days in December:
3.5 days
The month with the highest number of snowfall days is February (7.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature
New Haven, CT
The best month for swimming (with the highest average sea temperature) is August (73°F).
The coldest month (with the lowest average sea temperature) is February (38.5°F).
Average daylight / Average sunshine
New Haven, CT
- Average daylight in January:
9h and 36min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - 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 6min - Average sunshine in February:
4h and 42min - Average sunshine in March:
6h and 24min - Average sunshine in April:
8h and 24min - Average sunshine in May:
8h and 42min - Average sunshine in June:
9h and 36min
- Average sunshine in July:
10h and 36min - Average sunshine in August:
10h and 30min - Average sunshine in September:
8h and 54min - Average sunshine in October:
6h and 0min - 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 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days
New Haven, CT
- Average sunshine days in January:
17 days - Average sunshine days in February:
12.8 days - Average sunshine days in March:
13.5 days - Average sunshine days in April:
12.7 days - Average sunshine days in May:
11.9 days - Average sunshine days in June:
11.4 days
- Average sunshine days in July:
11.6 days - Average sunshine days in August:
11.3 days - Average sunshine days in September:
13.9 days - Average sunshine days in October:
14.6 days - Average sunshine days in November:
17.3 days - Average sunshine days in December:
15.4 days
The month with the most sunshine days is November (17.3 days).
The month with the least sunshine days is August (11.3 days).
Average UV index
New Haven, 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
New Haven, CT
The months with the most cloud cover are February and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility
New Haven, 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).





