| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 30°F | 49°F | 39°F | 3.2" |
| February | 33°F | 51°F | 41°F | 3.1" |
| March | 42°F | 63°F | 52°F | 5.3" |
| April | 51°F | 73°F | 62°F | 6.2" |
| May | 60°F | 81°F | 70°F | 7.1" |
| June | 69°F | 91°F | 80°F | 2.7" |
| July | 72°F | 91°F | 81°F | 3.4" |
| August | 71°F | 91°F | 80°F | 3.1" |
| September | 63°F | 85°F | 73°F | 3.5" |
| October | 51°F | 75°F | 61°F | 4.1" |
| November | 41°F | 61°F | 50°F | 4.0" |
| December | 34°F | 51°F | 42°F | 5.5" |
| Index | Harrisburg | Arkansas | National |
| Air quality index | 45 | 38 | 42 |
| Pollution index | 485,658 | 1,487,822 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 221 |
| Days with moderate air quality | 139 |
| Days w/ poor A.Q. for sensitive groups | 5 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.080% |
| Mercury | 0.020% |
| City | Population | Air Quality Index | National Avg. |
| Weiner, AR | 823 | 45 | 10.0% |
| Fisher, AR | 139 | 45 | 10.0% |
| Bay, AR | 2,341 | 45 | 10.0% |
| Waldenburg, AR | 42 | 45 | 10.0% |
| Trumann, AR | 7,000 | 45 | 10.0% |
| Harrisburg, AR | 2,874 | 45 | 10.0% |
| City | Population | Air Quality Index | National Avg. |
| Syracuse, IN | 2,874 | 37 | 26.0% |
| Brandenburg, KY | 2,874 | 39 | 22.0% |
| Saint-Isidore, QC | 2,874 | n/a | |
| Brighton, AL | 2,873 | 53 | 6.0% |
| Greensboro, MD | 2,873 | 42 | 16.0% |
| Harrisburg, AR | 2,874 | 45 | 10.0% |
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