| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 25°F | 42°F | 33°F | 3.3" |
| February | 25°F | 43°F | 34°F | 2.4" |
| March | 33°F | 53°F | 42°F | 3.4" |
| April | 43°F | 66°F | 54°F | 3.8" |
| May | 52°F | 75°F | 63°F | 3.9" |
| June | 62°F | 83°F | 72°F | 5.3" |
| July | 67°F | 88°F | 77°F | 5.1" |
| August | 65°F | 85°F | 75°F | 4.7" |
| September | 59°F | 79°F | 68°F | 3.5" |
| October | 48°F | 68°F | 57°F | 4.2" |
| November | 37°F | 57°F | 46°F | 2.9" |
| December | 31°F | 47°F | 38°F | 4.3" |
| Index | Yardley | Pennsylvania | National |
| Air quality index | 41 | 45 | 42 |
| Pollution index | 3,313,920 | 4,584,805 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 280 |
| Days with moderate air quality | 83 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.350% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.004% |
| Lead | 0.350% |
| Mercury | 0.340% |
| City | Population | Air Quality Index | National Avg. |
| Harlingen, NJ | 481 | 41 | 18.0% |
| Kingston, NJ | 963 | 41 | 18.0% |
| Rocky Hill, NJ | 655 | 41 | 18.0% |
| New Hope, PA | 2,518 | 41 | 18.0% |
| Fieldsboro, NJ | 761 | 41 | 18.0% |
| Yardley, PA | 2,496 | 41 | 18.0% |
| City | Population | Air Quality Index | National Avg. |
| Lake Crystal, MN | 2,496 | 46 | 8.0% |
| Silver Lake, OH | 2,496 | 43 | 14.0% |
| Redfield, SD | 2,496 | 20 | 60.0% |
| Saint-Mathieu, QC | 2,496 | n/a | |
| Santa Claus, IN | 2,495 | 6 | 88.0% |
| Yardley, PA | 2,496 | 41 | 18.0% |
Here are the best places to live in Pennsylvania
These are the 10 cheapest cities in Pennsylvania
Most Dangerous Cities In The US
Safest Cities In The US