| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 22°F | 38°F | 30°F | 5.3" |
| February | 22°F | 41°F | 31°F | 4.5" |
| March | 31°F | 52°F | 41°F | 6.9" |
| April | 41°F | 65°F | 53°F | 6.5" |
| May | 51°F | 74°F | 62°F | 7.6" |
| June | 60°F | 82°F | 71°F | 8.8" |
| July | 64°F | 87°F | 75°F | 7.6" |
| August | 62°F | 83°F | 72°F | 8.9" |
| September | 55°F | 77°F | 66°F | 10.8" |
| October | 44°F | 66°F | 55°F | 8.6" |
| November | 34°F | 54°F | 44°F | 6.0" |
| December | 28°F | 43°F | 35°F | 6.6" |
| Index | Myerstown | Pennsylvania | National |
| Air quality index | 42 | 45 | 42 |
| Pollution index | 11,091,200 | 4,584,805 | 2,726,193 |
| Measurement | Total |
| Days measured | 360 |
| Days with good air quality | 278 |
| Days with moderate air quality | 78 |
| Days w/ poor A.Q. for sensitive groups | 4 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.140% |
| Carbon Tetrachloride | 0.030% |
| Lead | 0.310% |
| Mercury | 0.004% |
| City | Population | Air Quality Index | National Avg. |
| Mount Aetna, PA | 518 | 42 | 16.0% |
| Rehrersburg, PA | 194 | 42 | 16.0% |
| Schubert, PA | 193 | 42 | 16.0% |
| Wernersville, PA | 2,757 | 42 | 16.0% |
| Pine Grove, PA | 2,088 | 42 | 16.0% |
| Myerstown, PA | 3,217 | 42 | 16.0% |
| City | Population | Air Quality Index | National Avg. |
| Frostproof, FL | 3,217 | 36 | 28.0% |
| Canyon Creek, WA | 3,218 | 24 | 52.0% |
| St. Maries, ID | 3,219 | 10 | 80.0% |
| Country Squire Lakes, IN | 3,220 | 35 | 30.0% |
| Four Bridges, OH | 3,220 | 54 | 8.0% |
| Myerstown, PA | 3,217 | 42 | 16.0% |
Here are the best places to live in Pennsylvania
These are the largest cities in Pennsylvania
These are the 10 cheapest cities in Pennsylvania
Check out the 10 safest cities in Pennsylvania