| 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 | East Rocky Hill | 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. |
| Skillman, NJ | 476 | 41 | 18.0% |
| Bradley Gardens, NJ | 14,714 | 41 | 18.0% |
| Manville, NJ | 10,193 | 41 | 18.0% |
| South Bound Brook, NJ | 4,541 | 41 | 18.0% |
| East Millstone, NJ | 693 | 41 | 18.0% |
| East Rocky Hill, NJ | 335 | 41 | 18.0% |
| City | Population | Air Quality Index | National Avg. |
| Brocton, IL | 335 | 42 | 16.0% |
| Greeley County, KS | 335 | 15 | 70.0% |
| Luther, MI | 335 | 36 | 28.0% |
| Spivey's Corner, NC | 335 | 41 | 18.0% |
| Alsace Manor, PA | 335 | 42 | 16.0% |
| East Rocky Hill, NJ | 335 | 41 | 18.0% |
Here are the best places to live in New Jersey
These are the 10 cheapest cities in New Jersey
Most Dangerous Cities In The US
Most Dangerous States In The US