| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 8°F | 27°F | 18°F | 7.6" |
| February | 9°F | 28°F | 18°F | 7.4" |
| March | 18°F | 38°F | 28°F | 5.0" |
| April | 33°F | 56°F | 44°F | 4.5" |
| May | 44°F | 69°F | 56°F | 3.7" |
| June | 54°F | 77°F | 65°F | 4.6" |
| July | 58°F | 80°F | 69°F | 4.3" |
| August | 56°F | 79°F | 67°F | 3.5" |
| September | 48°F | 74°F | 60°F | 2.9" |
| October | 39°F | 59°F | 48°F | 4.8" |
| November | 28°F | 46°F | 37°F | 2.7" |
| December | 16°F | 32°F | 24°F | 6.2" |
| Index | Champlain | New York | National |
| Air quality index | 37 | 43 | 42 |
| Pollution index | 3,508,050 | 6,179,275 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 335 |
| Days with moderate air quality | 30 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.004% |
| Benzene | 0.040% |
| Carbon Tetrachloride | 0.005% |
| Lead | 0.010% |
| Mercury | 0.003% |
| City | Population | Air Quality Index | National Avg. |
| Altona, NY | 836 | 0 | 100.0% |
| Mooers, NY | 460 | 0 | 100.0% |
| Alburgh, VT | 431 | 37 | 26.0% |
| Chazy, NY | 737 | 37 | 26.0% |
| West Chazy, NY | 415 | 37 | 26.0% |
| Champlain, NY | 1,361 | 37 | 26.0% |
| City | Population | Air Quality Index | National Avg. |
| La Harpe, IL | 1,361 | 29 | 42.0% |
| Foscoe, NC | 1,361 | 26 | 48.0% |
| Sherburne, NY | 1,361 | 27 | 46.0% |
| Irishtown-Summerside, NL | 1,361 | n/a | |
| Gjoa Haven, NU | 1,361 | n/a | |
| Champlain, NY | 1,361 | 37 | 26.0% |