| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 24°F | 43°F | 33°F | 2.3" |
| February | 25°F | 45°F | 34°F | 1.7" |
| March | 33°F | 56°F | 43°F | 2.9" |
| April | 42°F | 68°F | 55°F | 3.7" |
| May | 51°F | 76°F | 63°F | 4.5" |
| June | 60°F | 84°F | 72°F | 3.9" |
| July | 64°F | 88°F | 76°F | 3.3" |
| August | 62°F | 86°F | 74°F | 3.1" |
| September | 56°F | 80°F | 67°F | 3.3" |
| October | 45°F | 68°F | 56°F | 4.2" |
| November | 35°F | 57°F | 45°F | 2.4" |
| December | 28°F | 47°F | 37°F | 3.2" |
| Index | Spring Gap | Maryland | National |
| Air quality index | 36 | 43 | 42 |
| Pollution index | 314,680 | 5,342,367 | 2,726,193 |
| Measurement | Total |
| Days measured | 359 |
| Days with good air quality | 340 |
| Days with moderate air quality | 19 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.004% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| McCoole, MD | 529 | 36 | 28.0% |
| Gilmore, MD | 315 | 36 | 28.0% |
| National, MD | 64 | 36 | 28.0% |
| Vale Summit, MD | 140 | 36 | 28.0% |
| Barrelville, MD | 45 | 36 | 28.0% |
| Spring Gap, MD | 40 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Sunrise, AK | 40 | 31 | 38.0% |
| Edgewood, CA | 40 | 42 | 16.0% |
| McClenney Tract, CA | 40 | 67 | 34.0% |
| Sequoia Crest, CA | 40 | 66 | 32.0% |
| Coleman, GA | 40 | 40 | 20.0% |
| Spring Gap, MD | 40 | 36 | 28.0% |