| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 25°F | 42°F | 33°F | 3.3" |
| February | 25°F | 43°F | 34°F | 2.4" |
| March | 33°F | 53°F | 42°F | 3.4" |
| April | 43°F | 66°F | 54°F | 3.8" |
| May | 52°F | 75°F | 63°F | 3.9" |
| June | 62°F | 83°F | 72°F | 5.3" |
| July | 67°F | 88°F | 77°F | 5.1" |
| August | 65°F | 85°F | 75°F | 4.7" |
| September | 59°F | 79°F | 68°F | 3.5" |
| October | 48°F | 68°F | 57°F | 4.2" |
| November | 37°F | 57°F | 46°F | 2.9" |
| December | 31°F | 47°F | 38°F | 4.3" |
| Index | Princeton | New Jersey | National |
| Air quality index | 41 | 45 | 42 |
| Pollution index | 3,313,920 | 7,246,891 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 280 |
| Days with moderate air quality | 83 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.350% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.004% |
| Lead | 0.350% |
| Mercury | 0.340% |
| City | Population | Air Quality Index | National Avg. |
| Milltown, NJ | 6,973 | 41 | 18.0% |
| Middlebush, NJ | 2,737 | 41 | 18.0% |
| Somerset, NJ | 24,119 | 41 | 18.0% |
| Hulmeville, PA | 1,001 | 41 | 18.0% |
| Tullytown, PA | 2,215 | 41 | 18.0% |
| Princeton, NJ | 31,161 | 41 | 18.0% |
| City | Population | Air Quality Index | National Avg. |
| Needham, MA | 31,177 | 43 | 14.0% |
| Michigan City, IN | 31,191 | 37 | 26.0% |
| Naugatuck, CT | 31,201 | 41 | 18.0% |
| Centereach, NY | 31,100 | 43 | 14.0% |
| Sherwood, AR | 31,225 | 45 | 10.0% |
| Princeton, NJ | 31,161 | 41 | 18.0% |
Here are the best places to live in New Jersey
See the best places to live in Princeton
Safest Cities In The US
These are the largest cities in New Jersey