Portageville, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.8 °C (low) to 20.6 °C (high). Annual precipitation averages 1287.3 Millimeters. Portageville is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.2 °C | 6.8 °C | 94.49 mm |
| February | -0.4 °C | 9.6 °C | 100.58 mm |
| March | 4.1 °C | 14.9 °C | 117.09 mm |
| April | 9.4 °C | 21.3 °C | 131.06 mm |
| May | 15.3 °C | 26.2 °C | 140.97 mm |
| June | 19.8 °C | 30.7 °C | 99.82 mm |
| July | 21.6 °C | 32.1 °C | 97.28 mm |
| August | 20.4 °C | 31.7 °C | 79.25 mm |
| September | 16.1 °C | 28.4 °C | 92.2 mm |
| October | 9.6 °C | 22.5 °C | 104.39 mm |
| November | 3.8 °C | 14.8 °C | 109.98 mm |
| December | -0.4 °C | 8.7 °C | 120.14 mm |
| Annual | 9.8 °C | 20.6 °C | 1287.25 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |