| 2023 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 6a: -10F to -5F | |
| 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: | 67a - Northern Limestone/Dolomite Valleys | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 17036 - Hummelstown, PA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 22 | 23 | 31 | 40 | 50 | 60 | 64 | 63 | 55 | 43 | 35 | 27 | 43 |
| Avg Max Temp (°F) | 37 | 41 | 51 | 63 | 73 | 81 | 85 | 83 | 76 | 65 | 53 | 42 | 62 |
| Avg Precip (In.) | 3.34 | 2.74 | 3.51 | 3.41 | 4.39 | 4.12 | 3.72 | 3.29 | 3.92 | 3.15 | 3.48 | 3.15 | 42.21 |