| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 26°F | 42°F | 34°F | 6.3" |
| February | 24°F | 42°F | 32°F | 4.9" |
| March | 31°F | 50°F | 40°F | 7.3" |
| April | 46°F | 67°F | 55°F | 5.0" |
| May | 56°F | 76°F | 65°F | 9.9" |
| June | 64°F | 83°F | 73°F | 8.3" |
| July | 71°F | 87°F | 78°F | 8.3" |
| August | 67°F | 84°F | 75°F | 7.8" |
| September | 61°F | 80°F | 70°F | 4.9" |
| October | 54°F | 72°F | 62°F | 6.3" |
| November | 38°F | 56°F | 46°F | 5.9" |
| December | 33°F | 46°F | 39°F | 5.8" |
| Index | Garwood | New Jersey | National |
| Air quality index | 51 | 45 | 42 |
| Pollution index | 12,837,200 | 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 | 0.110% |
| Carbon Tetrachloride | 0.050% |
| Lead | 0.020% |
| Mercury | 0.230% |
| City | Population | Air Quality Index | National Avg. |
| Mendham, NJ | 4,880 | 34 | 32.0% |
| Middlebush, NJ | 2,737 | 41 | 18.0% |
| Griggstown, NJ | 858 | 41 | 18.0% |
| Finderne, NJ | 5,775 | 41 | 18.0% |
| Somerville, NJ | 12,139 | 41 | 18.0% |
| Garwood, NJ | 4,341 | 51 | 2.0% |
| City | Population | Air Quality Index | National Avg. |
| Tontitown, AR | 4,341 | 44 | 12.0% |
| South Haven, MI | 4,340 | 39 | 22.0% |
| Elberton, GA | 4,342 | 44 | 12.0% |
| Camanche, IA | 4,342 | 42 | 16.0% |
| Walton, KY | 4,343 | 54 | 8.0% |
| Garwood, NJ | 4,341 | 51 | 2.0% |
Here are the best places to live in New Jersey
Safest Cities In The US
See the best places to live in Garwood
These are the 10 cheapest cities in New Jersey