Grand Pass, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.2 °C (low) to 18.1 °C (high). Annual precipitation averages 1007.4 Millimeters. Grand Pass is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.7 °C | 2.9 °C | 35.81 mm |
| February | -5.3 °C | 5.9 °C | 46.23 mm |
| March | 0.1 °C | 12.3 °C | 67.31 mm |
| April | 5.7 °C | 18.6 °C | 102.11 mm |
| May | 11.9 °C | 23.8 °C | 127.76 mm |
| June | 17.4 °C | 28.7 °C | 124.97 mm |
| July | 19.6 °C | 30.9 °C | 113.28 mm |
| August | 18.1 °C | 30.2 °C | 105.41 mm |
| September | 13 °C | 26.3 °C | 101.09 mm |
| October | 6.6 °C | 19.8 °C | 81.53 mm |
| November | 0.3 °C | 12.1 °C | 58.42 mm |
| December | -4.9 °C | 5.3 °C | 43.43 mm |
| Annual | 6.2 °C | 18.1 °C | 1007.35 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |