| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 23°F | 39°F | 30°F | 3.0" |
| February | 23°F | 40°F | 31°F | 2.6" |
| March | 30°F | 49°F | 39°F | 3.5" |
| April | 41°F | 62°F | 50°F | 4.2" |
| May | 50°F | 71°F | 60°F | 4.2" |
| June | 60°F | 79°F | 69°F | 5.1" |
| July | 66°F | 84°F | 74°F | 4.4" |
| August | 64°F | 82°F | 72°F | 4.2" |
| September | 57°F | 77°F | 66°F | 4.3" |
| October | 47°F | 65°F | 55°F | 5.1" |
| November | 37°F | 54°F | 45°F | 3.1" |
| December | 29°F | 44°F | 36°F | 4.5" |
| Index | Harrison | New York | National |
| Air quality index | 51 | 43 | 42 |
| Pollution index | 2,299,930 | 6,179,275 | 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 | 0.002% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Glenville, CT | 3,040 | 43 | 14.0% |
| Darien, CT | 22,334 | 43 | 14.0% |
| Stamford, CT | 133,529 | 43 | 14.0% |
| West Hills, NY | 5,374 | 43 | 14.0% |
| Cove Neck, NY | 237 | 43 | 14.0% |
| Harrison, NY | 29,018 | 51 | 2.0% |
| City | Population | Air Quality Index | National Avg. |
| Englewood, NJ | 29,019 | 51 | 2.0% |
| Temescal Valley, CA | 29,022 | 89 | 78.0% |
| Eagle, ID | 29,040 | 36 | 28.0% |
| Jeffersontown, KY | 29,051 | 49 | 2.0% |
| Aberdeen, SD | 29,054 | 20 | 60.0% |
| Harrison, NY | 29,018 | 51 | 2.0% |