| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 20°F | 36°F | 27°F | 4.8" |
| February | 17°F | 36°F | 26°F | 5.2" |
| March | 25°F | 43°F | 34°F | 8.7" |
| April | 35°F | 55°F | 45°F | 9.9" |
| May | 45°F | 65°F | 54°F | 9.0" |
| June | 55°F | 77°F | 66°F | 3.2" |
| July | 60°F | 81°F | 70°F | 5.0" |
| August | 61°F | 83°F | 71°F | 1.9" |
| September | 53°F | 77°F | 65°F | 4.2" |
| October | 45°F | 64°F | 54°F | 9.9" |
| November | 32°F | 52°F | 42°F | 5.4" |
| December | 22°F | 38°F | 30°F | 6.9" |
| Index | Gloucester | Massachusetts | National |
| Air quality index | 43 | 40 | 42 |
| Pollution index | 24,018,000 | 8,399,610 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 291 |
| Days with moderate air quality | 73 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.030% |
| Benzene | 0.220% |
| Carbon Tetrachloride | 0.100% |
| Lead | 0.280% |
| Mercury | 0.130% |
| City | Population | Air Quality Index | National Avg. |
| Newburyport, MA | 18,788 | 37 | 26.0% |
| Salisbury, MA | 5,226 | 37 | 26.0% |
| Beverly, MA | 43,236 | 43 | 14.0% |
| Swampscott, MA | 15,599 | 43 | 14.0% |
| Nahant, MA | 3,632 | 43 | 14.0% |
| Gloucester, MA | 31,315 | 43 | 14.0% |
| City | Population | Air Quality Index | National Avg. |
| Lawrenceville, GA | 31,316 | 37 | 26.0% |
| Grimsby, ON | 31,320 | n/a | |
| Eldersburg, MD | 31,301 | 46 | 8.0% |
| Elizabethtown, KY | 31,333 | 39 | 22.0% |
| Opelika, AL | 31,335 | 42 | 16.0% |
| Gloucester, MA | 31,315 | 43 | 14.0% |