Princeton (NJ) Temperature by Month

The average annual maximum temperature in Princeton, New Jersey, United States of America is 18°C (64°F), with daytime highs ranging from 4°C (39°F) in January to 31°C (88°F) in July. This page covers monthly averages, day-night differences, and how Princeton compares to cities worldwide.

Visitors to Princeton will encounter a climate influenced by big temperature differences across the year. Nighttime 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 Princeton by month:

Low temperatures are most often recorded between 4 AM and 6 AM, while highs typically occur around 3 PM. July, the city's warmest month, sees 269 hours of sunshine.

The chart below shows the average temperature throughout the year:

Princeton's average annual maximum temperature is 18°C (64°F). To put that in context, here's how it compares to a few well-known destinations:

Seville, Spain averages 23°C (73°F) a year, one of the warmer cities in Western Europe, with long hot summers.

Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.

Shanghai, China averages 21°C (70°F) a year, with warm summers, mild winters, and a noticeable spring and autumn.

Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate, hot dry summers and mild wet winters.

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 Princeton's weather, including monthly rainfall, sunshine hours, and humidity, visit our Princeton climate page.