| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 36°F | 48°F | 42°F | 2.6" |
| February | 37°F | 50°F | 43°F | 2.1" |
| March | 40°F | 54°F | 46°F | 2.1" |
| April | 43°F | 57°F | 49°F | 1.9" |
| May | 47°F | 61°F | 53°F | 2.2" |
| June | 50°F | 65°F | 56°F | 1.0" |
| July | 53°F | 68°F | 59°F | 0.5" |
| August | 52°F | 69°F | 59°F | 0.8" |
| September | 49°F | 66°F | 57°F | 1.2" |
| October | 45°F | 59°F | 52°F | 2.5" |
| November | 40°F | 53°F | 46°F | 3.4" |
| December | 35°F | 47°F | 41°F | 2.4" |
| Index | Oak Harbor | Washington | National |
| Air quality index | 24 | 36 | 42 |
| Pollution index | 1,626,160 | 4,541,850 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 361 |
| Days with moderate air quality | 4 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.005% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.020% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Whidbey Island Station, WA | 2,452 | 24 | 52.0% |
| Cavalero, WA | 5,557 | 24 | 52.0% |
| Kayak Point, WA | 1,540 | 24 | 52.0% |
| Stanwood, WA | 7,422 | 24 | 52.0% |
| Anacortes, WA | 17,678 | 24 | 52.0% |
| Oak Harbor, WA | 24,266 | 24 | 52.0% |
| City | Population | Air Quality Index | National Avg. |
| Apollo Beach, FL | 24,263 | 43 | 14.0% |
| North Augusta, SC | 24,271 | 47 | 6.0% |
| Ashland, CA | 24,254 | 40 | 20.0% |
| Jacksonville Beach, FL | 24,280 | 43 | 14.0% |
| Bailey's Crossroads, VA | 24,246 | 47 | 6.0% |
| Oak Harbor, WA | 24,266 | 24 | 52.0% |