| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 34°F | 48°F | 40°F | 5.4" |
| February | 36°F | 52°F | 43°F | 3.7" |
| March | 39°F | 57°F | 47°F | 4.9" |
| April | 42°F | 63°F | 52°F | 2.9" |
| May | 48°F | 71°F | 58°F | 2.6" |
| June | 53°F | 76°F | 63°F | 1.7" |
| July | 57°F | 84°F | 69°F | 0.5" |
| August | 57°F | 84°F | 69°F | 0.4" |
| September | 52°F | 79°F | 64°F | 1.5" |
| October | 46°F | 66°F | 55°F | 3.7" |
| November | 40°F | 54°F | 47°F | 6.2" |
| December | 34°F | 47°F | 40°F | 6.2" |
| Index | Hough | Vancouver | Washington |
| Air quality index | 38 | 38 | 36 |
| Pollution index | 1,899,410 | 1,899,410 | 4,541,850 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 285 |
| Days with moderate air quality | 77 |
| Days w/ poor A.Q. for sensitive groups | 3 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.003% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.010% |
| Mercury | 0.002% |
| City | Population | Air Quality Index | National Avg. |
| Maywood Park, OR | 1,224 | 38 | 24.0% |
| Brush Prairie, WA | 2,721 | 38 | 24.0% |
| Lewisville, WA | 2,166 | 38 | 24.0% |
| Beaverton, OR | 98,567 | 38 | 24.0% |
| Milwaukie, OR | 21,086 | 38 | 24.0% |
| Vancouver, WA | 182,792 | 38 | 24.0% |
| City | Population | Air Quality Index | National Avg. |
| Brownsville, TX | 182,230 | 44 | 12.0% |
| Fort Lauderdale, FL | 181,818 | 41 | 18.0% |
| Chattanooga, TN | 181,370 | 46 | 8.0% |
| Sioux Falls, SD | 180,927 | 36 | 28.0% |
| Worcester, MA | 185,186 | 40 | 20.0% |
| Vancouver, WA | 182,792 | 38 | 24.0% |
Here are the best places to live in Washington
Check out the 10 most dangerous cities in Washington
These are the largest cities in Washington
See the best places to live in Vancouver