| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 26°F | 39°F | 33°F | 2.3" |
| February | 30°F | 48°F | 38°F | 1.2" |
| March | 35°F | 56°F | 46°F | 1.7" |
| April | 41°F | 65°F | 53°F | 1.6" |
| May | 49°F | 75°F | 62°F | 1.4" |
| June | 56°F | 83°F | 69°F | 2.8" |
| July | 64°F | 93°F | 79°F | 0.7" |
| August | 61°F | 92°F | 77°F | 1.0" |
| September | 53°F | 82°F | 68°F | 1.2" |
| October | 42°F | 64°F | 53°F | 2.1" |
| November | 33°F | 49°F | 41°F | 1.3" |
| December | 25°F | 37°F | 31°F | 1.8" |
| Index | Grandview | Washington | National |
| Air quality index | 37 | 36 | 42 |
| Pollution index | 697,942 | 4,541,850 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 303 |
| Days with moderate air quality | 62 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.020% |
| Benzene | 0.004% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.010% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Prosser, WA | 6,288 | 37 | 26.0% |
| Granger, WA | 3,806 | 38 | 24.0% |
| Sunnyside, WA | 16,703 | 38 | 24.0% |
| Mabton, WA | 2,192 | 38 | 24.0% |
| Outlook, WA | 158 | 38 | 24.0% |
| Grandview, WA | 11,075 | 37 | 26.0% |
| City | Population | Air Quality Index | National Avg. |
| Forest, VA | 11,075 | 26 | 48.0% |
| Celebration, FL | 11,077 | 39 | 22.0% |
| Kaneohe Station, HI | 11,072 | 30 | 40.0% |
| Lindon, UT | 11,072 | 46 | 8.0% |
| Two Rivers, WI | 11,079 | 36 | 28.0% |
| Grandview, WA | 11,075 | 37 | 26.0% |
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