Gravois Mills, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.2 °C (low) to 19.2 °C (high). Annual precipitation averages 1132.6 Millimeters. Gravois Mills 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 | -5.8 °C | 5.2 °C | 54.1 mm |
| February | -3.9 °C | 7.9 °C | 56.39 mm |
| March | 0.9 °C | 13.7 °C | 78.74 mm |
| April | 6.3 °C | 19.9 °C | 126.49 mm |
| May | 12.3 °C | 24.2 °C | 144.27 mm |
| June | 17.6 °C | 28.7 °C | 115.57 mm |
| July | 19.9 °C | 31.2 °C | 108.46 mm |
| August | 18.9 °C | 30.8 °C | 104.14 mm |
| September | 14.3 °C | 26.7 °C | 111.76 mm |
| October | 7.7 °C | 20.8 °C | 91.44 mm |
| November | 1.8 °C | 13.4 °C | 79.5 mm |
| December | -3.2 °C | 7.4 °C | 61.72 mm |
| Annual | 7.2 °C | 19.2 °C | 1132.58 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |