| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 20°F | 36°F | 27°F | 1.1" |
| February | 26°F | 47°F | 36°F | 0.7" |
| March | 33°F | 58°F | 44°F | 1.2" |
| April | 37°F | 66°F | 51°F | 0.7" |
| May | 45°F | 76°F | 60°F | 1.2" |
| June | 53°F | 86°F | 69°F | 0.7" |
| July | 61°F | 97°F | 79°F | 0.1" |
| August | 57°F | 93°F | 75°F | 0.2" |
| September | 48°F | 83°F | 64°F | 0.4" |
| October | 38°F | 67°F | 51°F | 0.8" |
| November | 29°F | 50°F | 38°F | 1.1" |
| December | 20°F | 37°F | 28°F | 1.8" |
| Index | Nyssa | Oregon | National |
| Air quality index | 36 | 32 | 42 |
| Pollution index | 1,647,310 | 7,156,356 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 293 |
| Days with moderate air quality | 60 |
| Days w/ poor A.Q. for sensitive groups | 9 |
| Days with unhealthy air quality | 3 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.001% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| New Plymouth, ID | 1,693 | 36 | 28.0% |
| Wilder, ID | 1,788 | 36 | 28.0% |
| Notus, ID | 614 | 36 | 28.0% |
| Ontario, OR | 11,298 | 36 | 28.0% |
| Fruitland, ID | 5,518 | 36 | 28.0% |
| Nyssa, OR | 3,261 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Surf City, NC | 3,261 | 34 | 32.0% |
| Saint-Alphonse-Rodriguez, QC | 3,261 | n/a | |
| Bifrost-Riverton, MB | 3,261 | n/a | |
| Marion, AL | 3,260 | 35 | 30.0% |
| New Baden, IL | 3,260 | 54 | 8.0% |
| Nyssa, OR | 3,261 | 36 | 28.0% |