| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 23°F | 40°F | 31°F | 2.6" |
| February | 23°F | 42°F | 32°F | 2.4" |
| March | 31°F | 53°F | 41°F | 3.1" |
| April | 42°F | 66°F | 54°F | 3.6" |
| May | 51°F | 75°F | 63°F | 3.7" |
| June | 61°F | 84°F | 72°F | 4.8" |
| July | 66°F | 88°F | 77°F | 5.0" |
| August | 64°F | 85°F | 74°F | 4.7" |
| September | 57°F | 79°F | 68°F | 4.4" |
| October | 46°F | 67°F | 56°F | 4.8" |
| November | 35°F | 55°F | 45°F | 2.7" |
| December | 29°F | 45°F | 36°F | 3.8" |
| Index | Shartlesville | Pennsylvania | National |
| Air quality index | 42 | 45 | 42 |
| Pollution index | 1,279,530 | 4,584,805 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 279 |
| Days with moderate air quality | 80 |
| Days w/ poor A.Q. for sensitive groups | 5 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.002% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Hyde Park borough, PA | 462 | 42 | 16.0% |
| Muhlenberg Park, PA | 1,354 | 42 | 16.0% |
| Stony Creek Mills, PA | 770 | 42 | 16.0% |
| Myerstown, PA | 3,301 | 42 | 16.0% |
| Richland, PA | 1,839 | 42 | 16.0% |
| Shartlesville, PA | 495 | 42 | 16.0% |
| City | Population | Air Quality Index | National Avg. |
| Nenana, AK | 495 | 38 | 24.0% |
| Hurtsboro, AL | 495 | 42 | 16.0% |
| Runnells, IA | 495 | 39 | 22.0% |
| Sun River Terrace, IL | 495 | 55 | 10.0% |
| Kensington, KS | 495 | 19 | 62.0% |
| Shartlesville, PA | 495 | 42 | 16.0% |