| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 34°F | 46°F | 39°F | 9.0" |
| February | 34°F | 49°F | 40°F | 4.0" |
| March | 36°F | 52°F | 43°F | 4.2" |
| April | 38°F | 58°F | 47°F | 2.9" |
| May | 43°F | 65°F | 53°F | 4.4" |
| June | 49°F | 70°F | 59°F | 3.3" |
| July | 54°F | 79°F | 65°F | 1.9" |
| August | 53°F | 77°F | 64°F | 3.2" |
| September | 49°F | 72°F | 59°F | 3.7" |
| October | 42°F | 60°F | 50°F | 5.2" |
| November | 39°F | 51°F | 44°F | 8.1" |
| December | 32°F | 44°F | 38°F | 6.1" |
| Index | North Fort Lewis | Washington | National |
| Air quality index | 30 | 36 | 42 |
| Pollution index | 6,704,330 | 4,541,850 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 323 |
| Days with moderate air quality | 42 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.003% |
| Benzene | 0.100% |
| Carbon Tetrachloride | 0.004% |
| Lead | 0.030% |
| Mercury | 0.003% |
| City | Population | Air Quality Index | National Avg. |
| Gig Harbor, WA | 10,659 | 18 | 64.0% |
| Wollochet, WA | 7,438 | 18 | 64.0% |
| Dash Point, WA | 1,045 | 18 | 64.0% |
| Key Center, WA | 3,773 | 18 | 64.0% |
| Artondale, WA | 14,469 | 18 | 64.0% |
| North Fort Lewis, WA | 6,545 | 30 | 40.0% |
| City | Population | Air Quality Index | National Avg. |
| Braidwood, IL | 6,545 | 0 | 100.0% |
| Plessisville, QC | 6,545 | n/a | |
| Gimli, MB | 6,545 | n/a | |
| Horseheads, NY | 6,544 | 35 | 30.0% |
| Opp, AL | 6,547 | 35 | 30.0% |
| North Fort Lewis, WA | 6,545 | 30 | 40.0% |