| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 32°F | 47°F | 38°F | 4.1" |
| February | 33°F | 53°F | 42°F | 3.0" |
| March | 38°F | 60°F | 48°F | 4.8" |
| April | 39°F | 61°F | 50°F | 2.9" |
| May | 45°F | 70°F | 57°F | 4.8" |
| June | 48°F | 72°F | 59°F | 2.1" |
| July | 53°F | 83°F | 68°F | 1.3" |
| August | 51°F | 84°F | 67°F | 1.2" |
| September | 44°F | 75°F | 59°F | 2.8" |
| October | 42°F | 61°F | 50°F | 3.8" |
| November | 33°F | 52°F | 42°F | 7.5" |
| December | 33°F | 45°F | 39°F | 11.3" |
| Index | West Slope | Oregon | National |
| Air quality index | 38 | 32 | 42 |
| Pollution index | 3,247,580 | 7,156,356 | 2,726,193 |
| 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 | 0.002% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.500% |
| Lead | 0.040% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Orchards, WA | 26,289 | 38 | 24.0% |
| Durham, OR | 1,764 | 38 | 24.0% |
| Jennings Lodge, OR | 8,500 | 38 | 24.0% |
| Milwaukie, OR | 21,086 | 38 | 24.0% |
| Tigard, OR | 54,149 | 38 | 24.0% |
| West Slope, OR | 6,799 | 38 | 24.0% |
| City | Population | Air Quality Index | National Avg. |
| Cullowhee, NC | 6,798 | 44 | 12.0% |
| Laurel, MT | 6,797 | 21 | 58.0% |
| Kirtland, OH | 6,801 | 50 | = 100 |
| St. Albans, VT | 6,796 | 37 | 26.0% |
| Loomis, CA | 6,802 | 52 | 4.0% |
| West Slope, OR | 6,799 | 38 | 24.0% |
Here are the best places to live in Oregon
See the best places to live in West Slope
Most Dangerous Cities In The US
These are the 10 cheapest cities in Oregon