Climate averages 1991–2020
New Haven weather
by month.
See how the year changes. July has the highest average daily maximum; July has the lowest average monthly rainfall.
Long-term climate patterns, not a forecast for a particular trip.
Across the year New Haven averages a daytime high of 14.8°C and a nighttime low of 8.0°C, with about 1,316 mm of rain on roughly 123 days. July is the warmest month (average high 27.0°C) and January the coolest (2.7°C). December is the wettest month with 137 mm; July is the driest with 82 mm.
The annual picture
A year in New Haven
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
New Haven climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 2.7°C-3.6°C | -3.6°C | 108 | 10.1 | 9.610 h |
| February | 3.6°C-3.3°C | -3.3°C | 97 | 9.2 | 10.611 h |
| March | 7.3°C0.0°C | 0.0°C | 128 | 10.9 | 11.912 h |
| April | 13.1°C5.2°C | 5.2°C | 116 | 11.5 | 13.313 h |
| May | 18.4°C10.6°C | 10.6°C | 98 | 11.6 | 14.514 h |
| June | 23.6°C16.2°C | 16.2°C | 98 | 10.5 | 15.115 h |
| July | 27.0°C19.9°C | 19.9°C | 82 | 9.5 | 14.815 h |
| August | 26.3°C19.6°C | 19.6°C | 102 | 9.6 | 13.814 h |
| September | 22.6°C16.2°C | 16.2°C | 109 | 8.9 | 12.513 h |
| October | 16.5°C10.5°C | 10.5°C | 129 | 10.1 | 11.111 h |
| November | 10.7°C4.9°C | 4.9°C | 110 | 9.5 | 9.910 h |
| December | 5.6°C0.0°C | 0.0°C | 137 | 11.2 | 9.39 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
Nearby cities
- BridgeportUnited States · 26 kmHigh 15.0°C · Low 8.1°C · 1,211 mm rain a year
- WaterburyUnited States · 30 kmHigh 15.3°C · Low 6.6°C · 1,151 mm rain a year
- New BritainUnited States · 41 kmHigh 15.3°C · Low 6.0°C · 1,111 mm rain a year
- DanburyUnited States · 45 kmHigh 15.1°C · Low 6.5°C · 1,207 mm rain a year
- NorwalkUnited States · 45 kmHigh 15.3°C · Low 8.1°C · 1,116 mm rain a year
- HartfordUnited States · 55 kmHigh 15.4°C · Low 5.8°C · 1,111 mm rain a year
- StamfordUnited States · 58 kmHigh 15.5°C · Low 8.1°C · 1,116 mm rain a year
- GreenburghUnited States · 82 kmHigh 15.6°C · Low 7.7°C · 1,117 mm rain a year
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC-5, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 41.30°, -72.90° (3 km from the city centre). Rain comes from the 0.25° cell at 41.25°, -73.00°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.