| | Olney, MD | Bethesda, MD | United States |
| Rainfall | 43.3 | 42.7 | 38.1 |
| Snowfall | 15.8 | 17.2 | 27.8 |
| Precipitation Days | 111.9 | 113.9 | 106.2 |
| Sunny | 199 | 197 | 205 |
| Avg. July High | 87 | 86.7 | 85.8 |
| Avg. Jan. Low | 25 | 25.3 | 21.7 |
| Comfort Index (higher=better) | 7.3 | 7.3 | 7 |
| UV Index | 4.1 | 4.1 | 4.3 |
| Elevation ft. | 541 | 318 | 2443 |