New Haven (CT) Temperature by Month

The average annual maximum temperature in New Haven, Connecticut, United States of America is 16°C (61°F), with daytime highs ranging from 4°C (39°F) in January to 29°C (84°F) in July. This page covers monthly averages, day-night differences, and how New Haven compares to cities worldwide.

Depending on the time of the year, temperatures range from comfortable to cold in New Haven. At night, minimum temperatures range from 19°C (66°F) in July to -6°C (21°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in New Haven by month:

Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM. July, the warmest month, sees 293 hours of sunshine.

The chart below shows the average temperature throughout the year:

New Haven's average annual maximum temperature is 16°C (61°F). To put that in context, here's how it compares to a few well-known destinations:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.

San Francisco, USA averages 19°C (66°F) annually, but with little seasonal variation, summers are often cool and foggy, winters mild.

Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In New Haven, January is the coolest month, with average highs of 4°C (39°F) and humidity around 64%, considered high. In July, the warmest month, temperatures average 29°C (84°F) with 68% humidity, conditions that feel high. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on New Haven's weather, including monthly rainfall, sunshine hours, and humidity, visit our New Haven climate page.