| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 14°F | 35°F | 24°F | 1.2" |
| February | 17°F | 39°F | 26°F | 1.4" |
| March | 29°F | 54°F | 40°F | 5.7" |
| April | 39°F | 64°F | 50°F | 5.3" |
| May | 50°F | 75°F | 61°F | 8.2" |
| June | 61°F | 85°F | 72°F | 8.5" |
| July | 65°F | 88°F | 76°F | 6.0" |
| August | 62°F | 84°F | 72°F | 6.4" |
| September | 54°F | 79°F | 65°F | 4.7" |
| October | 40°F | 65°F | 51°F | 6.4" |
| November | 28°F | 52°F | 39°F | 2.2" |
| December | 16°F | 36°F | 25°F | 2.7" |
| Index | Shelby | Nebraska | National |
| Air quality index | 31 | 86 | 42 |
| Pollution index | 574,580 | 590,627 | 2,726,193 |
| Measurement | Total |
| Days measured | 360 |
| Days with good air quality | 338 |
| Days with moderate air quality | 22 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.002% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Silver Creek, NE | 504 | 19 | 62.0% |
| Duncan, NE | 502 | 19 | 62.0% |
| Benedict, NE | 292 | 19 | 62.0% |
| Osceola, NE | 855 | 19 | 62.0% |
| Stromsburg, NE | 1,066 | 19 | 62.0% |
| Shelby, NE | 741 | 31 | 38.0% |
| City | Population | Air Quality Index | National Avg. |
| Soda Bay, CA | 741 | 31 | 38.0% |
| Dakota, IL | 741 | 42 | 16.0% |
| Bovey, MN | 741 | 35 | 30.0% |
| Napi Headquarters, NM | 741 | 49 | 2.0% |
| Pastoria, VA | 741 | 41 | 18.0% |
| Shelby, NE | 741 | 31 | 38.0% |