| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 10°F | 29°F | 19°F | 1.4" |
| February | 12°F | 32°F | 22°F | 1.9" |
| March | 25°F | 47°F | 36°F | 2.3" |
| April | 36°F | 62°F | 49°F | 4.9" |
| May | 47°F | 72°F | 59°F | 4.5" |
| June | 58°F | 81°F | 69°F | 5.3" |
| July | 61°F | 84°F | 72°F | 6.9" |
| August | 59°F | 81°F | 70°F | 4.2" |
| September | 51°F | 76°F | 63°F | 3.2" |
| October | 40°F | 63°F | 51°F | 3.4" |
| November | 28°F | 49°F | 38°F | 2.2" |
| December | 15°F | 33°F | 24°F | 2.5" |
| Index | Graf | Iowa | National |
| Air quality index | 29 | 39 | 42 |
| Pollution index | 2,365,950 | 1,154,535 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 304 |
| Days with moderate air quality | 60 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.170% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.004% |
| Lead | 0.040% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Asbury, IA | 5,931 | 29 | 42.0% |
| Dubuque, IA | 58,052 | 29 | 42.0% |
| Rickardsville, IA | 215 | 29 | 42.0% |
| East Dubuque, IL | 1,569 | 29 | 42.0% |
| Worthington, IA | 360 | 29 | 42.0% |
| Graf, IA | 44 | 29 | 42.0% |
| City | Population | Air Quality Index | National Avg. |
| Ocotillo, CA | 44 | 58 | 16.0% |
| Whitley Gardens, CA | 44 | 46 | 8.0% |
| Crestone, CO | 44 | 16 | 68.0% |
| Lynn, CO | 44 | 20 | 60.0% |
| Fenwick, CT | 44 | 37 | 26.0% |
| Graf, IA | 44 | 29 | 42.0% |
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