Harrisburg, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 44.5 °F (low) to 64.5 °F (high). Annual precipitation averages 42.5 Inches. Harrisburg is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.0 °F | 37.7 °F | 2.0 in. |
| February | 23.8 °F | 42.8 °F | 2.25 in. |
| March | 33.3 °F | 54.2 °F | 3.11 in. |
| April | 43.7 °F | 65.2 °F | 4.63 in. |
| May | 54.4 °F | 74.3 °F | 5.09 in. |
| June | 63.5 °F | 83.1 °F | 5.04 in. |
| July | 67.4 °F | 87.3 °F | 4.49 in. |
| August | 65.3 °F | 86.3 °F | 3.79 in. |
| September | 56.7 °F | 79.3 °F | 3.82 in. |
| October | 45.4 °F | 67.4 °F | 3.38 in. |
| November | 34.6 °F | 53.9 °F | 2.83 in. |
| December | 25.4 °F | 42.0 °F | 2.1 in. |
| Annual | 44.5 °F | 64.5 °F | 42.53 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |