| 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 6b: -5F to 0F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| Average Last Frost Date: | Apr. 21 - Apr. 30 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 67b - Northern Shale Valleys | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 17020 - Duncannon, PA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 20 | 21 | 29 | 39 | 48 | 58 | 63 | 61 | 54 | 42 | 33 | 25 | 41 |
| Avg Max Temp (°F) | 37 | 40 | 51 | 63 | 72 | 81 | 85 | 83 | 76 | 64 | 52 | 41 | 62 |
| Avg Precip (In.) | 2.93 | 2.66 | 3.47 | 3.27 | 4.12 | 4.03 | 3.55 | 3.39 | 3.84 | 3.24 | 3.46 | 3.14 | 41.09 |