| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F | |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F | |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| Average Last Frost Date: | Apr. 11 - Apr. 20 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 72f - River Hills | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 63461 - Palmyra, MO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 17 | 22 | 32 | 42 | 53 | 62 | 67 | 64 | 56 | 44 | 33 | 22 | 43 |
| Avg Max Temp (°F) | 35 | 41 | 53 | 65 | 75 | 84 | 88 | 86 | 79 | 68 | 52 | 39 | 64 |
| Avg Precip (In.) | 1.52 | 1.79 | 3.01 | 3.57 | 4.89 | 3.55 | 4.12 | 3.51 | 3.42 | 2.89 | 3.18 | 2.35 | 37.79 |