New Haven, Connecticut Climate
New Haven weather by month — average highs and lows, rainfall, all-time records, and the warming record since 1948
- Hottest month
- 82°FJuly average high
- Coldest month
- 23°FJanuary average low
- Precipitation
- 41.8 ina year
- Wettest month
- April4.2 in on average
1991–2020 NOAA climate normals
At 1:30 AM EDT on Sep 21 it was 61°F in New Haven — 2° above the 59°F typical for that hour (estimated from the Sep 21 normal high of 73°F and low of 55°F, interpolated from the monthly normals).
New Haven weather by month
Average high, low, and rainfall for every month, from New Haven’s 1991–2020 climate normals, the standard 30-year reference period. Each band runs from the month’s average low to its average high: a tall band is a big day-to-night swing.
| Month | Avg High | Avg Low | Rainfall |
|---|---|---|---|
| January | 38°F | 23°F | 2.7 in |
| February | 40°F | 24°F | 2.8 in |
| March | 47°F | 30°F | 3.7 in |
| April | 58°F | 39°F | 4.2 in |
| May | 68°F | 49°F | 3.5 in |
| June | 76°F | 59°F | 3.5 in |
| July | 82°F | 66°F | 3.4 in |
| August | 81°F | 65°F | 3.5 in |
| September | 75°F | 57°F | 4.0 in |
| October | 64°F | 46°F | 3.8 in |
| November | 53°F | 36°F | 3.1 in |
| December | 44°F | 29°F | 3.5 in |
| Annual | 61°F | 44°F | 41.8 in |
New Haven’s warming record since 1948
Not what a typical year looks like, but how the typical year has changed. Each stripe is one complete year’s average temperature at the station, 1948 to 2025, colored against the mean of those years: blue for cooler years, red for warmer ones. No trend line is fitted to them: the latest stretch of complete years with no gap over 10 years is 2002–2025, only 24 years (a trend needs at least 30).
New Haven rainfall by month
New Haven averages 41.8 inches of precipitation a year. The wettest month is April and the driest is January.
New Haven temperature records
- All-time record high
- 101°Fset July 22, 2011
- All-time record low
- -8°Fset January 19, 1948
Records are drawn from the nearest long-term weather station’s full daily history, so they capture the most extreme single day New Haven has recorded — not a typical seasonal high or low.
Frequently asked
- What is the hottest month in New Haven?
- July is New Haven's hottest month, with the highest average daily high of the year. The month-by-month table above shows New Haven's exact average high and low for each month, based on the 1991–2020 climate normals — the standard 30-year reference period meteorologists use.
- What is the coldest month in New Haven?
- January is New Haven's coldest month, with the lowest average daily low of the year. The averages-by-month chart above gives the exact average high and low for every month, so you can see how cold a typical winter day runs.
- How much does it rain in New Haven?
- New Haven's total annual precipitation and its wettest and driest months are shown in the rainfall-by-month section above. Those figures are 1991–2020 normals — the average monthly precipitation total across that 30-year window — so they reflect a typical year rather than any single wet or dry season.
- What months are best to visit New Haven?
- The most comfortable months in New Haven are usually the shoulder seasons — spring and fall — when temperatures sit between the summer peak and winter low and rainfall is moderate. Compare the average high, low, and precipitation for each month in the table above to pick the window that fits the weather you want.
- Has New Haven gotten hotter?
- There isn't enough data to say. The warming-stripes chart above plots New Haven's annual mean temperature for every complete year of station data from 1948 to 2025, but no trend line is fitted: the latest stretch of complete years with no gap over 10 years is 2002–2025, only 24 years (a trend needs at least 30). A shorter or broken record can't separate a climate trend from normal year-to-year swings.
- What is the record high temperature in New Haven?
- New Haven's all-time record high — the hottest single day in the station record — is shown in the records section above, along with the date it occurred. Records are drawn from the nearest long-term weather station's full daily history, which begins in 1948, so they capture the most extreme heat on record, not just a typical summer day.
- What is the record low temperature in New Haven?
- New Haven's all-time record low and the date it was set appear in the records section above. Like the record high, it comes from the station's full daily history back to 1948, so it reflects the coldest day on record rather than an average winter low.