| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 25°F | 41°F | 32°F | 3.2" |
| February | 25°F | 40°F | 32°F | 3.0" |
| March | 33°F | 52°F | 42°F | 3.2" |
| April | 44°F | 65°F | 54°F | 4.0" |
| May | 52°F | 74°F | 62°F | 4.0" |
| June | 64°F | 83°F | 73°F | 5.1" |
| July | 67°F | 86°F | 76°F | 5.1" |
| August | 67°F | 85°F | 75°F | 3.5" |
| September | 59°F | 77°F | 67°F | 5.2" |
| October | 47°F | 66°F | 55°F | 4.2" |
| November | 38°F | 55°F | 45°F | 3.2" |
| December | 28°F | 42°F | 35°F | 5.1" |
| Index | Middletown | Pennsylvania | National |
| Air quality index | 44 | 45 | 42 |
| Pollution index | 11,091,200 | 4,584,805 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 252 |
| Days with moderate air quality | 107 |
| Days w/ poor A.Q. for sensitive groups | 5 |
| Days with unhealthy air quality | 1 |
| 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. |
| Dover, PA | 2,124 | 41 | 18.0% |
| Weigelstown, PA | 14,156 | 41 | 18.0% |
| Falmouth, PA | 569 | 41 | 18.0% |
| Manchester, PA | 2,680 | 41 | 18.0% |
| Mount Wolf, PA | 1,413 | 41 | 18.0% |
| Middletown, PA | 9,410 | 44 | 12.0% |
| City | Population | Air Quality Index | National Avg. |
| Country Club Estates, GA | 9,408 | 36 | 28.0% |
| Rio Vista, CA | 9,407 | 45 | 10.0% |
| Atoka, TN | 9,407 | 45 | 10.0% |
| Pryor Creek, OK | 9,417 | 36 | 28.0% |
| Cairo, GA | 9,395 | 40 | 20.0% |
| Middletown, PA | 9,410 | 44 | 12.0% |
Here are the best places to live in Pennsylvania
Most Dangerous States In The US
Check out the 10 most dangerous cities in Pennsylvania
See the best places to live in Middletown