| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 1 - May 10 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 55a - Clayey High Lime Till Plains |
| Heat Zone Days: | 1 - 7 days Over 86°F |
Annual Climate Data for ZIP Code 45887 - Spencerville, OH | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 17 | 20 | 29 | 39 | 50 | 59 | 63 | 61 | 54 | 42 | 33 | 23 | 41 |
| Avg Max Temp (°F) | 32 | 37 | 48 | 60 | 72 | 81 | 84 | 82 | 76 | 64 | 50 | 37 | 60 |
| Avg Precip (In.) | 2.11 | 1.92 | 2.66 | 3.44 | 3.78 | 4.04 | 4 | 3.47 | 2.91 | 2.4 | 2.98 | 2.61 | 36.31 |