Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
January | 18°F | 30°F | 24°F | 1.2" |
February | 25°F | 44°F | 33°F | 2.4" |
March | 31°F | 57°F | 43°F | 1.8" |
April | 35°F | 65°F | 50°F | 1.5" |
May | 42°F | 75°F | 59°F | 2.6" |
June | 49°F | 80°F | 64°F | 4.2" |
July | 58°F | 92°F | 75°F | 1.6" |
August | 54°F | 91°F | 73°F | 0.8" |
September | 45°F | 78°F | 61°F | 2.2" |
October | 37°F | 61°F | 48°F | 2.3" |
November | 27°F | 41°F | 34°F | 3.6" |
December | 18°F | 30°F | 25°F | 4.0" |
Index | Grand Coulee | Washington | National |
Air quality index | 18 | 36 | 42 |
Pollution index | 2,683,410 | 4,541,850 | 2,726,193 |
Measurement | Total |
Days measured | 365 |
Days with good air quality | 339 |
Days with moderate air quality | 26 |
Days w/ poor A.Q. for sensitive groups | 0 |
Days with unhealthy air quality | 0 |
Pollutant | Total |
Arsenic | 0.000% |
Benzene | 0.040% |
Carbon Tetrachloride | 0.004% |
Lead | 0.030% |
Mercury | 0.000% |
City | Population | Air Quality Index | National Avg. |
Elmer City, WA | 301 | 18 | 64.0% |
Coulee Dam, WA | 1,355 | 18 | 64.0% |
Wilbur, WA | 767 | 18 | 64.0% |
Electric City, WA | 944 | 18 | 64.0% |
Keller, WA | 204 | 43 | 14.0% |
Grand Coulee, WA | 1,257 | 18 | 64.0% |
City | Population | Air Quality Index | National Avg. |
Edgerton, MN | 1,257 | 36 | 28.0% |
Mansfield, MO | 1,257 | 39 | 22.0% |
Union Springs, NY | 1,257 | 34 | 32.0% |
Hilldale, PA | 1,257 | 38 | 24.0% |
Prosperity, SC | 1,257 | 43 | 14.0% |
Grand Coulee, WA | 1,257 | 18 | 64.0% |