| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F |
| Average First Frost Date: | Oct. 21 - Oct. 31 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | Cfa - Humid Subtropical Climate |
| Ecoregion: | 70d - Knobs-Lower Scioto Dissected Plateau |
| Heat Zone Days: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 45662 - Portsmouth, OH | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 20 | 23 | 31 | 41 | 50 | 59 | 63 | 62 | 54 | 42 | 33 | 25 | 42 |
| Avg Max Temp (°F) | 40 | 44 | 55 | 66 | 75 | 82 | 86 | 85 | 78 | 68 | 55 | 44 | 65 |
| Avg Precip (In.) | 3.09 | 2.81 | 3.59 | 3.36 | 4.04 | 3.93 | 3.77 | 3.91 | 3.08 | 2.63 | 2.74 | 3.11 | 40.06 |