| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 26°F | 41°F | 33°F | 3.2" |
| February | 26°F | 42°F | 33°F | 2.5" |
| March | 34°F | 53°F | 42°F | 6.9" |
| April | 43°F | 65°F | 53°F | 3.6" |
| May | 52°F | 74°F | 63°F | 6.0" |
| June | 61°F | 81°F | 71°F | 6.5" |
| July | 66°F | 86°F | 76°F | 7.9" |
| August | 63°F | 83°F | 73°F | 11.0" |
| September | 56°F | 77°F | 66°F | 6.8" |
| October | 46°F | 66°F | 55°F | 9.4" |
| November | 37°F | 55°F | 45°F | 2.9" |
| December | 31°F | 46°F | 38°F | 7.7" |
| Index | King of Prussia | Pennsylvania | National |
| Air quality index | 51 | 45 | 42 |
| Pollution index | 12,485,100 | 4,584,805 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 180 |
| Days with moderate air quality | 169 |
| Days w/ poor A.Q. for sensitive groups | 16 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.020% |
| Benzene | 0.100% |
| Carbon Tetrachloride | 0.100% |
| Lead | 0.120% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Souderton, PA | 7,184 | 42 | 16.0% |
| Pottstown, PA | 23,534 | 42 | 16.0% |
| South Pottstown, PA | 2,301 | 42 | 16.0% |
| Greenfields, PA | 1,161 | 42 | 16.0% |
| Royersford, PA | 4,937 | 42 | 16.0% |
| King of Prussia, PA | 22,618 | 51 | 2.0% |
| City | Population | Air Quality Index | National Avg. |
| Del City, OK | 22,594 | 48 | 4.0% |
| East Patchogue, NY | 22,646 | 43 | 14.0% |
| Shelbyville, TN | 22,648 | 31 | 38.0% |
| Corcoran, CA | 22,663 | 56 | 12.0% |
| Belton, TX | 22,671 | 42 | 16.0% |
| King of Prussia, PA | 22,618 | 51 | 2.0% |