| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 21 - May 31 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 61c - Low Lime Drift Plain |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 16137 - Mercer, PA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 16 | 18 | 26 | 35 | 45 | 54 | 58 | 56 | 49 | 39 | 31 | 22 | 37 |
| Avg Max Temp (°F) | 34 | 38 | 48 | 60 | 70 | 78 | 82 | 81 | 74 | 63 | 50 | 39 | 60 |
| Avg Precip (In.) | 2.72 | 2.5 | 3.25 | 3.54 | 3.76 | 4.63 | 4.24 | 3.86 | 4.3 | 2.78 | 3.64 | 3.26 | 42.47 |