| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 25°F | 42°F | 33°F | 4.2" |
| February | 25°F | 43°F | 34°F | 3.6" |
| March | 33°F | 52°F | 42°F | 3.9" |
| April | 44°F | 66°F | 54°F | 4.4" |
| May | 53°F | 75°F | 63°F | 4.9" |
| June | 63°F | 84°F | 72°F | 5.3" |
| July | 69°F | 89°F | 78°F | 4.5" |
| August | 66°F | 86°F | 76°F | 5.0" |
| September | 60°F | 81°F | 69°F | 3.5" |
| October | 49°F | 69°F | 58°F | 4.8" |
| November | 38°F | 58°F | 47°F | 3.1" |
| December | 31°F | 47°F | 38°F | 5.0" |
| Index | Rockleigh | New Jersey | National |
| Air quality index | 51 | 45 | 42 |
| Pollution index | 7,043,200 | 7,246,891 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 169 |
| Days with moderate air quality | 180 |
| Days w/ poor A.Q. for sensitive groups | 16 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.050% |
| Carbon Tetrachloride | 0.020% |
| Lead | 0.030% |
| Mercury | 0.020% |
| City | Population | Air Quality Index | National Avg. |
| Mount Ivy, NY | 7,390 | 36 | 28.0% |
| Croton-on-Hudson, NY | 8,121 | 36 | 28.0% |
| Thiells, NY | 4,247 | 36 | 28.0% |
| Pomona, NY | 3,058 | 36 | 28.0% |
| Tuxedo Park, NY | 542 | 36 | 28.0% |
| Rockleigh, NJ | 650 | 51 | 2.0% |
| City | Population | Air Quality Index | National Avg. |
| Grand Ridge, IL | 650 | 0 | 100.0% |
| Milroy, IN | 650 | 28 | 44.0% |
| Hatley, MS | 650 | 39 | 22.0% |
| Hungry Horse, MT | 650 | 37 | 26.0% |
| Gilbert, SC | 650 | 43 | 14.0% |
| Rockleigh, NJ | 650 | 51 | 2.0% |
Here are the best places to live in New Jersey
See the best places to live in Rockleigh
Check out the 10 most dangerous cities in New Jersey
These are the largest cities in New Jersey