New Haven, Connecticut climate: Normal weather by month, frost dates and records
New Haven's normal year runs from 23°F January nights to 82°F July afternoons, with 41.8 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.1°C, January lows of −5°C, July highs of 28°C, 1,061 mm of precipitation a year.
- NOAA stationNew Haven Tweed Airport
- Station IDUSW00014758
- Location41.26°N 72.89°W
- Elevation3 ft (1 m)
- From the center4 miles
- Population137,562
On October 14, the normal high in New Haven is 64°F and the normal low 46°F, and the chance of measurable rain or snow is 35%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for New Haven.
- Jan 38° 23°
- Feb 40° 24°
- Mar 47° 30°
- Apr 58° 39°
- May 68° 49°
- Jun 76° 59°
- Jul 82° 66°
- Aug 81° 65°
- Sep 75° 57°
- Oct 64° 46°
- Nov 53° 36°
- Dec 44° 29°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in New Haven each month?
July is the warmest month, with normal highs of 82°F; January the coldest, with normal lows of 23°F. The most precipitation falls in April (4.19 in), the least in January (2.72 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 38°F | 23°F | 30.5°F | 2.72 | 10 | <1 | 25 | 9 h 30 min |
| February | 40°F | 24°F | 32.0°F | 2.84 | 9 | <1 | 23 | 10 h 40 min |
| March | 47°F | 30°F | 38.5°F | 3.66 | 10 | <1 | 17 | 11 h 50 min |
| April | 58°F | 39°F | 48.5°F | 4.19 | 11 | <1 | 4 | 13 h 20 min |
| May | 68°F | 49°F | 58.5°F | 3.54 | 13 | <1 | <1 | 14 h 30 min |
| June | 76°F | 59°F | 67.9°F | 3.47 | 12 | 1 | <1 | 15 h 10 min |
| July | 82°F | 66°F | 73.9°F | 3.36 | 10 | 3 | <1 | 14 h 50 min |
| August | 81°F | 65°F | 72.9°F | 3.55 | 10 | 2 | <1 | 13 h 50 min |
| September | 75°F | 57°F | 66.0°F | 4.03 | 9 | <1 | <1 | 12 h 30 min |
| October | 64°F | 46°F | 54.7°F | 3.78 | 11 | <1 | 2 | 11 h 10 min |
| November | 53°F | 36°F | 44.7°F | 3.12 | 9 | <1 | 10 | 9 h 50 min |
| December | 44°F | 29°F | 36.3°F | 3.53 | 11 | <1 | 21 | 9 h 10 min |
| Year (annual) | 61°F | 44°F | 52.0°F | 41.79 | 124 | 6 | 102 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 3°C | −5°C | −0.8°C | 69 mm |
| February | 5°C | −5°C | 0.0°C | 72 mm |
| March | 8°C | −1°C | 3.6°C | 93 mm |
| April | 14°C | 4°C | 9.2°C | 106 mm |
| May | 20°C | 10°C | 14.7°C | 90 mm |
| June | 25°C | 15°C | 19.9°C | 88 mm |
| July | 28°C | 19°C | 23.3°C | 85 mm |
| August | 27°C | 18°C | 22.7°C | 90 mm |
| September | 24°C | 14°C | 18.9°C | 102 mm |
| October | 18°C | 8°C | 12.6°C | 96 mm |
| November | 12°C | 2°C | 7.1°C | 79 mm |
| December | 7°C | −2°C | 2.4°C | 90 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Bridgeport (15 miles away), gets 34 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014758; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit New Haven?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (9).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014758.
When is the last frost in New Haven?
In New Haven, the last spring frost (32°F) comes after April 17 in half of years and after May 1 in one year in ten; the first autumn frost comes before October 27 in half of years and before October 11 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 171 year in 10 after May 1; 9 in 10 after April 2
- First autumn frost, half of years before
- October 271 year in 10 before October 11; 9 in 10 before November 8
NOAA puts the median frost-free season at 193 days, and the season without a hard freeze (28°F) at 215 days.
A hard freeze (28°F) comes after April 4 in half of springs and before November 6 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts New Haven in zone 7a across its 6 ZIP code areas (7a in 06511, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, New Haven's NOAA station is in zone 7a: the coldest night of a typical year reaches 3°F (19 complete years).
Frost dates for every NOAA station in Connecticut · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00014758; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each New Haven ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. New Haven's 6 ZIP code areas are all in zone 7a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in New Haven?
In a normal year in New Haven, 6 days a year reach 90°F, 102 nights fall to 32°F or colder and 124 days bring measurable precipitation.
- Days at 90°F or more
- 6a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 102a normal year
- Days that stay below freezing
- 18high of 32°F or less
- Days with 0.01 inch of precipitation
- 124a normal year
The highest temperature in this station's record (since 1948) is 101°F, on July 22, 2011; the lowest is −8°F, on January 19, 1948.
The wettest calendar year on that record is 1953, with 53.67 in; the snowiest season is 1966–67, with 60.4 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00014758; records: ACIS (NOAA Regional Climate Centers), station USW00014758. Records use complete months only; a month missing more than three days is left out.
How sunny is New Haven?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around New Haven, 3.9 kWh per square metre a day. July is the sunniest month (79%) and December the cloudiest (67%). Among the 459 U.S. places of 50,000 or more, that ranks tied 352nd (with 32 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 70% | 1.9 |
| February | 70% | 2.7 |
| March | 69% | 3.7 |
| April | 71% | 4.9 |
| May | 70% | 5.5 |
| June | 74% | 5.9 |
| July | 79% | 6.0 |
| August | 79% | 5.3 |
| September | 78% | 4.4 |
| October | 71% | 2.9 |
| November | 72% | 2.1 |
| December | 67% | 1.5 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does New Haven need?
A normal year in New Haven brings 5,455 heating degree days, 2% more than the median U.S. place (5,373), and 765 cooling degree days, 16% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,028 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,068 | 0 |
| February | 923 | 0 |
| March | 820 | 0 |
| April | 494 | 1 |
| May | 215 | 15 |
| June | 36 | 121 |
| July | 2 | 277 |
| August | 3 | 246 |
| September | 63 | 93 |
| October | 331 | 10 |
| November | 611 | 0 |
| December | 890 | 0 |
| Year (annual) | 5,455 | 765 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00014758. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has New Haven been warmer than normal lately?
2024 averaged 56.0°F, 4.0°F above the 1991-2020 normal of 52.0°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 54.9°F | +2.9°F | 42.27 |
| 2022 | 54.8°F | +2.8°F | 26.52 |
| 2023 | 55.8°F | +3.8°F | – |
| 2024 | 56.0°F | +4.0°F | 46.66 |
Source: observed years: ACIS, station USW00014758. A year counts only with all twelve months complete.
How does New Haven's climate compare?
New Haven is warmer than 10 of the other 12 places with their own NOAA record in Connecticut, and wetter than 1. Across the 7,247 U.S. stations with normals, its annual mean of 52.0°F is warmer than 49%.
In the Köppen classification computed from these normals, New Haven is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near New Haven share this climate record?
5 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- West Haven, CTalso near: Ansonia (8 mi, 50.1°F a year); Mount Carmel (10 mi, 51.7°F a year)55,379 people · 4 mi W
- East Haven, CT27,953 people · 2 mi NE
- Branford Center, CT6,130 people · 4 mi E
- Woodmont, CT2,392 people · 6 mi SW
- Guilford Center, CT2,272 people · 11 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about New Haven's climate
What is the coldest month in New Haven?
January, with a normal high of 38°F and a normal low of 23°F. The warmest is July (82°F by day, 66°F at night).
Does it snow in New Haven?
Yes. NOAA publishes no 1991-2020 snowfall normal for New Haven's NOAA station; the nearest record that keeps one, Bridgeport (15 miles away), records 34 inches of snow in a normal year.
What is the rainiest month in New Haven?
April, with 4.19 in of precipitation in a normal year; the driest is January with 2.72 in.
What plant hardiness zone is New Haven in?
The USDA's 2023 map puts New Haven in zone 7a across its 6 ZIP code areas (7a in 06511, the largest). By the same method at New Haven's NOAA station, the coldest night of a typical year reaches 3°F (19 years, 1991-2020): zone 7a.
How late can frost come in New Haven?
In half of years the last 32°F night comes after April 17; in one year in ten it comes after May 1. Waiting until May 1 leaves about a one-in-ten chance of a later frost.
Nearby and next
- New Haven in OctoberThis month day by day, its records and recent years
- Connecticut climateThe statewide normals and every place in the state
- Mount Carmel, CT10 miles from this station, 51.7°F a year
- Ansonia, CT12 miles from this station, 50.1°F a year
- Bridgeport, CT14 miles from this station, 53.4°F a year
- Meriden, CT17 miles from this station, 50.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made