| 2023 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F 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: | Apr. 21 - Apr. 30 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 67a - Northern Limestone/Dolomite Valleys |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 17066 - Mount Union, PA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 19 | 20 | 28 | 37 | 47 | 56 | 60 | 59 | 52 | 40 | 32 | 24 | 39 |
| Avg Max Temp (°F) | 36 | 39 | 49 | 61 | 72 | 80 | 84 | 82 | 75 | 64 | 51 | 40 | 61 |
| Avg Precip (In.) | 2.6 | 2.36 | 3.37 | 3.23 | 3.69 | 3.87 | 2.77 | 2.9 | 3.37 | 3.2 | 2.89 | 2.63 | 36.88 |