Mountainburg, Arkansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.2 °C (low) to 21.9 °C (high). Annual precipitation averages 1373.4 Millimeters. Mountainburg is located in USDA Plant Hardiness Zone 7b. 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 | -2.3 °C | 9.5 °C | 94.23 mm |
| February | -0.4 °C | 12.2 °C | 74.68 mm |
| March | 3.8 °C | 16.7 °C | 115.06 mm |
| April | 8.6 °C | 22.2 °C | 130.56 mm |
| May | 13.8 °C | 26.2 °C | 155.19 mm |
| June | 18.5 °C | 30.5 °C | 113.79 mm |
| July | 20.6 °C | 33.2 °C | 104.65 mm |
| August | 19.9 °C | 33.1 °C | 97.79 mm |
| September | 15.8 °C | 29.1 °C | 126.49 mm |
| October | 9.3 °C | 23.1 °C | 124.46 mm |
| November | 3.7 °C | 16.2 °C | 138.18 mm |
| December | -0.7 °C | 10.7 °C | 98.3 mm |
| Annual | 9.2 °C | 21.9 °C | 1373.38 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 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 |