| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 24°F | 41°F | 31°F | 4.1" |
| February | 26°F | 44°F | 34°F | 5.6" |
| March | 34°F | 55°F | 43°F | 6.4" |
| April | 44°F | 68°F | 55°F | 6.1" |
| May | 55°F | 76°F | 64°F | 9.2" |
| June | 63°F | 84°F | 72°F | 6.0" |
| July | 66°F | 87°F | 76°F | 5.5" |
| August | 64°F | 85°F | 73°F | 7.7" |
| September | 58°F | 79°F | 67°F | 7.6" |
| October | 46°F | 67°F | 55°F | 9.4" |
| November | 36°F | 55°F | 44°F | 5.4" |
| December | 30°F | 46°F | 37°F | 6.8" |
| Index | Point of Rocks | Maryland | National |
| Air quality index | 40 | 43 | 42 |
| Pollution index | 5,553,870 | 5,342,367 | 2,726,193 |
| Measurement | Total |
| Days measured | 362 |
| Days with good air quality | 306 |
| Days with moderate air quality | 54 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.004% |
| Benzene | 0.070% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.410% |
| Mercury | 0.070% |
| City | Population | Air Quality Index | National Avg. |
| Hillsboro, VA | 203 | 38 | 24.0% |
| Woodburn, VA | 10,475 | 38 | 24.0% |
| Purcellville, VA | 10,402 | 38 | 24.0% |
| Hamilton, VA | 734 | 38 | 24.0% |
| Round Hill, VA | 714 | 38 | 24.0% |
| Point of Rocks, MD | 2,112 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Camino, CA | 2,112 | 52 | 4.0% |
| Pablo, MT | 2,112 | 37 | 26.0% |
| Essex Fells, NJ | 2,112 | 51 | 2.0% |
| South Amherst, OH | 2,112 | 50 | = 100 |
| One Hundred Mile House, BC | 2,112 | n/a | |
| Point of Rocks, MD | 2,112 | 40 | 20.0% |