| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 23°F | 40°F | 31°F | 3.0" |
| February | 23°F | 42°F | 32°F | 2.9" |
| March | 31°F | 52°F | 41°F | 3.5" |
| April | 42°F | 65°F | 52°F | 3.9" |
| May | 51°F | 74°F | 62°F | 4.0" |
| June | 60°F | 82°F | 71°F | 4.9" |
| July | 66°F | 87°F | 76°F | 4.9" |
| August | 63°F | 84°F | 73°F | 4.9" |
| September | 57°F | 78°F | 67°F | 3.7" |
| October | 46°F | 67°F | 56°F | 4.2" |
| November | 36°F | 55°F | 45°F | 2.8" |
| December | 29°F | 45°F | 36°F | 4.4" |
| Index | Morris Plains | New Jersey | National |
| Air quality index | 51 | 45 | 42 |
| Pollution index | 8,169,930 | 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 | 0.070% |
| Carbon Tetrachloride | 0.030% |
| Lead | 0.020% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Peapack and Gladstone, NJ | 2,582 | 34 | 32.0% |
| Chester, NJ | 1,514 | 34 | 32.0% |
| Lake Mohawk, NJ | 9,148 | 34 | 32.0% |
| Succasunna, NJ | 9,367 | 34 | 32.0% |
| Andover, NJ | 675 | 34 | 32.0% |
| Morris Plains, NJ | 5,888 | 51 | 2.0% |
| City | Population | Air Quality Index | National Avg. |
| Riverside, MD | 5,888 | 46 | 8.0% |
| Somerset, PA | 5,888 | 36 | 28.0% |
| St. James, NC | 5,889 | 34 | 32.0% |
| Attalla, AL | 5,885 | 43 | 14.0% |
| South Lebanon, OH | 5,885 | 54 | 8.0% |
| Morris Plains, NJ | 5,888 | 51 | 2.0% |
Here are the best places to live in New Jersey
See the best places to live in Morris Plains
These are the 10 cheapest cities in New Jersey
These are the largest cities in New Jersey