Grant City, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.4 °F (low) to 61.5 °F (high). Annual precipitation averages 38.5 Inches. Grant City is located in USDA Plant Hardiness Zone 5b. 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 | 13.8 °F | 32.8 °F | 0.87 in. |
| February | 18.2 °F | 38.0 °F | 1.33 in. |
| March | 28.6 °F | 50.6 °F | 2.23 in. |
| April | 39.4 °F | 62.4 °F | 3.95 in. |
| May | 51.2 °F | 72.5 °F | 5.54 in. |
| June | 61.0 °F | 81.3 °F | 5.4 in. |
| July | 65.3 °F | 85.9 °F | 4.79 in. |
| August | 62.9 °F | 84.3 °F | 4.21 in. |
| September | 53.9 °F | 77.2 °F | 3.72 in. |
| October | 41.4 °F | 65.0 °F | 3.02 in. |
| November | 29.6 °F | 50.0 °F | 1.99 in. |
| December | 19.5 °F | 37.5 °F | 1.41 in. |
| Annual | 40.4 °F | 61.5 °F | 38.46 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |