Tarkio, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.7 °C (low) to 17.2 °C (high). Annual precipitation averages 902.7 Millimeters. Tarkio is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.9 °C | 1.1 °C | 19.3 mm |
| February | -7.8 °C | 4.2 °C | 30.23 mm |
| March | -1.8 °C | 11.3 °C | 50.8 mm |
| April | 4.3 °C | 17.7 °C | 85.85 mm |
| May | 11.2 °C | 23.5 °C | 139.19 mm |
| June | 16.9 °C | 28.5 °C | 128.27 mm |
| July | 18.8 °C | 30.6 °C | 120.9 mm |
| August | 17.3 °C | 29.6 °C | 97.54 mm |
| September | 12 °C | 26.2 °C | 83.31 mm |
| October | 5 °C | 19.1 °C | 66.29 mm |
| November | -1.8 °C | 10.6 °C | 47.5 mm |
| December | -7.3 °C | 3.5 °C | 33.53 mm |
| Annual | 4.7 °C | 17.2 °C | 902.71 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |