Galena, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 44.2 °F (low) to 68.6 °F (high). Annual precipitation averages 46 Inches. Galena is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 22.7 °F | 44.8 °F | 2.7 in. |
| February | 25.7 °F | 49.6 °F | 2.64 in. |
| March | 33.8 °F | 59.1 °F | 4.17 in. |
| April | 42.9 °F | 69.1 °F | 4.77 in. |
| May | 53.2 °F | 76.7 °F | 5.14 in. |
| June | 62.1 °F | 85.3 °F | 4.6 in. |
| July | 66.0 °F | 90.1 °F | 4.22 in. |
| August | 64.5 °F | 89.4 °F | 3.08 in. |
| September | 56.0 °F | 81.7 °F | 4.65 in. |
| October | 44.0 °F | 71.1 °F | 3.04 in. |
| November | 33.8 °F | 58.2 °F | 4.11 in. |
| December | 25.8 °F | 48.1 °F | 2.87 in. |
| Annual | 44.2 °F | 68.6 °F | 45.99 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |