| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 17°F | 32°F | 24°F | 1.8" |
| February | 17°F | 33°F | 24°F | 1.2" |
| March | 27°F | 46°F | 35°F | 2.1" |
| April | 37°F | 59°F | 48°F | 2.7" |
| May | 48°F | 71°F | 60°F | 4.1" |
| June | 58°F | 80°F | 69°F | 3.5" |
| July | 62°F | 83°F | 73°F | 3.4" |
| August | 61°F | 81°F | 71°F | 3.2" |
| September | 54°F | 74°F | 63°F | 3.2" |
| October | 43°F | 62°F | 52°F | 2.7" |
| November | 32°F | 49°F | 40°F | 1.9" |
| December | 23°F | 36°F | 29°F | 1.7" |
| Index | Sylvan Lake | Michigan | National |
| Air quality index | 56 | 69 | 42 |
| Pollution index | 30,180,300 | 4,161,606 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 135 |
| Days with moderate air quality | 217 |
| Days w/ poor A.Q. for sensitive groups | 13 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.030% |
| Benzene | 0.390% |
| Carbon Tetrachloride | 0.080% |
| Lead | 0.130% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Lake Orion, MI | 3,240 | 38 | 24.0% |
| Oxford, MI | 3,621 | 38 | 24.0% |
| Village of Clarkston, MI | 846 | 38 | 24.0% |
| Holly, MI | 6,357 | 38 | 24.0% |
| Wixom, MI | 14,439 | 40 | 20.0% |
| Sylvan Lake, MI | 1,835 | 56 | 12.0% |
| City | Population | Air Quality Index | National Avg. |
| Ackley, IA | 1,835 | 39 | 22.0% |
| Mullens, WV | 1,835 | 295 | 490.0% |
| Cottonport, LA | 1,836 | 30 | 40.0% |
| Rogue River, OR | 1,834 | 26 | 48.0% |
| Brodheadsville, PA | 1,836 | 34 | 32.0% |
| Sylvan Lake, MI | 1,835 | 56 | 12.0% |