Portia, Arkansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.7 °F (low) to 69.6 °F (high). Annual precipitation averages 52 Inches. Portia 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 Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 28.7 °F | 45.5 °F | 4.09 in. |
| February | 31.8 °F | 50.5 °F | 4.16 in. |
| March | 39.6 °F | 60.1 °F | 4.83 in. |
| April | 49.1 °F | 70.4 °F | 5.32 in. |
| May | 59.4 °F | 79.0 °F | 5.43 in. |
| June | 67.7 °F | 87.4 °F | 3.58 in. |
| July | 71.2 °F | 90.1 °F | 3.65 in. |
| August | 68.9 °F | 89.0 °F | 3.92 in. |
| September | 60.9 °F | 83.0 °F | 3.64 in. |
| October | 48.9 °F | 72.9 °F | 4.12 in. |
| November | 39.1 °F | 59.2 °F | 4.87 in. |
| December | 31.6 °F | 48.4 °F | 4.34 in. |
| Annual | 49.7 °F | 69.6 °F | 51.95 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |