New Haven climate
New Haven (Connecticut, United States) has a hot-summer humid continental climate (Köppen Dfa). The average temperature over the year is 11 °C52 °F, and about 1,208 mm48 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
New Haven climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin | Frost days |
|---|---|---|---|---|---|
| Jan | 235 | −720 | −327 | 763.0 | 28 |
| Feb | 337 | −621 | −229 | 813.2 | 26 |
| Mar | 846 | −228 | 337 | 973.8 | 24 |
| Apr | 1559 | 338 | 948 | 1054.1 | 8 |
| May | 2170 | 949 | 1559 | 953.7 | 0 |
| Jun | 2678 | 1559 | 2069 | 1174.6 | 0 |
| Jul | 2985 | 1865 | 2475 | 1014.0 | 0 |
| Aug | 2984 | 1864 | 2374 | 1094.3 | 0 |
| Sep | 2578 | 1457 | 2067 | 1064.2 | 0 |
| Oct | 1864 | 745 | 1355 | 1214.8 | 2 |
| Nov | 1152 | 235 | 643 | 893.5 | 14 |
| Dec | 540 | −326 | 133 | 1114.4 | 26 |
| Year | 2985 | −720 | 1152 | 1,20848 | 128 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total. Frost days are for the whole grid cell.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 88% | 62% | 1.9 | 9:30 |
| Feb | 87% | 61% | 2.7 | 10:34 |
| Mar | 83% | 60% | 3.7 | 11:49 |
| Apr | 78% | 60% | 4.9 | 13:16 |
| May | 78% | 62% | 5.5 | 14:29 |
| Jun | 78% | 60% | 5.9 | 15:08 |
| Jul | 74% | 55% | 6.0 | 14:52 |
| Aug | 73% | 52% | 5.3 | 13:49 |
| Sep | 74% | 49% | 4.4 | 12:24 |
| Oct | 78% | 57% | 2.9 | 11:01 |
| Nov | 81% | 58% | 2.1 | 9:48 |
| Dec | 87% | 64% | 1.5 | 9:12 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of New Haven is like
The warmest month is July, with an average high of 29 °C85 °F and a low of 18 °C65 °F. The coldest is January, when highs average 2 °C35 °F and lows −7 °C20 °F. Seasons are strongly marked: the warmest month is on average 26.7 °C48 °F warmer than the coldest.
It is wet, with about 1,208 mm48 in of precipitation per year. Rain is spread fairly evenly through the year. The wettest month is October (121 mm4.8 in), the driest is January (76 mm3.0 in).
Relative humidity ranges from 73% in August to 88% in January. The clearest skies (lowest average cloud amount, 49%) are typical of September. Average wind speed near the ground ranges from 0 km/h (0 mph) in June to 3 km/h (2 mph) in February. Daylight lasts from about 9.2 hours in December to 15.1 hours in June.
A lasting snow cover is typical in December–March, when the average snow depth in the reanalysis exceeds 10 cm (deepest in January, about 16 cm).
Best time to visit New Haven
Based on these averages, the most comfortable months for sightseeing and outdoor activities are May and September: average highs of 21 °C70 °F to 25 °C78 °F with 95 mm3.7 in to 106 mm4.2 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of 2 °C35 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for New Haven
- Winter (December–February) — highs 235 to 5 °C40 °F, lows −720 to −3 °C26 °F, about 90 mm3.5 in of precipitation a month. Pack a winter coat, hat, gloves and warm, non-slip boots and shoes with good grip, as frost is common.
- Spring (March–May) — highs 846 to 21 °C70 °F, lows −228 to 9 °C49 °F, about 99 mm3.9 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Summer (June–August) — highs 2678 to 29 °C85 °F, lows 1559 to 18 °C65 °F, about 109 mm4.3 in of precipitation a month. Pack light summer clothes such as T-shirts, shorts or light dresses, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
- Autumn (September–November) — highs 1152 to 25 °C78 °F, lows 235 to 14 °C57 °F, about 105 mm4.1 in of precipitation a month. Pack light layers — T-shirts plus a light sweater or jacket, an extra layer for the cooler mornings and evenings and an umbrella or light rain jacket.
How New Haven compares
Compared with Bridgeport, about 26 km to the southwest, New Haven is on average 1 °C1.7 °F cooler and receives a similar amount of precipitation. The difference is largest in December (2.8 °C5.1 °F cooler).
Of the 222 places in the United States covered by World Climates, New Haven is the 182nd warmest by annual mean temperature and the 61st wettest by annual precipitation. See all of them on the United States climate page.
Places in other countries with the most similar temperature and rainfall pattern: Oshu (Japan, Dfa), Ichinoseki (Japan, Dfa) and Yamagata (Japan, Dfa).
Nearby places
- Bridgeport 26 km · 12 °C53 °F · 1,206 mm47 in
- Waterbury 30 km · 10 °C51 °F · 1,208 mm48 in
- Hartford 55 km · 10 °C51 °F · 1,201 mm47 in
- Stamford 58 km · 11 °C53 °F · 1,236 mm49 in
- Springfield 93 km · 10 °C51 °F · 1,201 mm47 in
- Manhattan 105 km · 11 °C52 °F · 1,236 mm49 in
- New York City 112 km · 12 °C54 °F · 1,312 mm52 in
- Brooklyn 113 km · 12 °C54 °F · 1,312 mm52 in
Frequently asked questions
What is the warmest month in New Haven?
July is the warmest month in New Haven, with an average high of 29 °C (85 °F) and an average low of 18 °C (65 °F).
What is the coldest month in New Haven?
January is the coldest month, with an average high of 2 °C (35 °F) and an average low of -7 °C (20 °F).
When does it rain the most in New Haven?
October is the wettest month with about 121 mm (4.8 in) of precipitation; January is the driest with about 76 mm (3.0 in).
What is the best time to visit New Haven?
Judging by long-term averages, the most comfortable months are May and September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 149 m, while New Haven lies at about 18 m. Temperatures on this page were therefore adjusted by +0.9 °C1.5 °F using the standard lapse rate of 6.5 °C per 1,000 m.