| 2023 Hardiness Zone: | Zone 7b: 5°F to 10°F | |
| 2012 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 6b: -5F to 0F | |
| Average First Frost Date: | Oct. 11 - Oct. 20 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 45e - Northern Inner Piedmont | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 20194 - Reston, VA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 23 | 25 | 32 | 41 | 51 | 60 | 65 | 63 | 56 | 43 | 35 | 27 | 43 |
| Avg Max Temp (°F) | 42 | 46 | 55 | 66 | 75 | 83 | 87 | 86 | 79 | 68 | 57 | 46 | 66 |
| Avg Precip (In.) | 3.14 | 2.71 | 3.62 | 3.23 | 4.12 | 3.77 | 3.75 | 3.69 | 4.09 | 3.34 | 3.37 | 3.17 | 42.02 |