| 2023 Hardiness Zone: | Zone 7b: 5°F to 10°F | |
| 2012 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 7a: 0F to 5F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| Average Last Frost Date: | Apr. 21 - Apr. 30 | |
| Koppen-Geiger Climate Zone: | Cfa - Humid Subtropical Climate | |
| Ecoregion: | 45e - Northern Inner Piedmont | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 22031 - Fairfax, VA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 24 | 26 | 33 | 42 | 52 | 61 | 66 | 64 | 58 | 45 | 36 | 28 | 44 |
| Avg Max Temp (°F) | 42 | 46 | 55 | 66 | 75 | 83 | 87 | 86 | 79 | 68 | 57 | 46 | 66 |
| Avg Precip (In.) | 3.36 | 2.85 | 3.91 | 3.33 | 4.48 | 3.76 | 4.23 | 3.99 | 4.4 | 3.53 | 3.46 | 3.22 | 44.5 |