| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 36°F | 46°F | 41°F | 6.8" |
| February | 36°F | 50°F | 43°F | 2.9" |
| March | 41°F | 56°F | 48°F | 6.1" |
| April | 43°F | 58°F | 49°F | 3.5" |
| May | 48°F | 66°F | 56°F | 3.5" |
| June | 51°F | 69°F | 58°F | 1.9" |
| July | 55°F | 77°F | 65°F | 3.2" |
| August | 55°F | 77°F | 64°F | 0.9" |
| September | 51°F | 69°F | 58°F | 3.3" |
| October | 47°F | 59°F | 52°F | 3.5" |
| November | 40°F | 49°F | 44°F | 6.5" |
| December | 37°F | 45°F | 41°F | 9.0" |
| Index | Ruston | Tacoma | Washington |
| Air quality index | 18 | 18 | 36 |
| Pollution index | 1,081,430 | 17,693,800 | 4,541,850 |
| Measurement | Total |
| Days measured | 340 |
| Days with good air quality | 338 |
| Days with moderate air quality | 2 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.300% |
| Carbon Tetrachloride | 0.050% |
| Lead | 0.110% |
| Mercury | 0.020% |
| City | Population | Air Quality Index | National Avg. |
| Bethel, WA | 4,182 | 18 | 64.0% |
| Ruston, WA | 1,329 | 18 | 64.0% |
| Dash Point, WA | 1,008 | 18 | 64.0% |
| Key Center, WA | 3,631 | 18 | 64.0% |
| Wauna, WA | 4,509 | 18 | 64.0% |
| Tacoma, WA | 215,766 | 18 | 64.0% |
| City | Population | Air Quality Index | National Avg. |
| Des Moines, IA | 215,408 | 39 | 22.0% |
| Richmond Hill, ON | 215,407 | n/a | |
| San Bernardino, CA | 216,784 | 89 | 78.0% |
| Enterprise, NV | 214,591 | 54 | 8.0% |
| Modesto, CA | 214,485 | 49 | 2.0% |
| Tacoma, WA | 215,766 | 18 | 64.0% |
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