Sulphur Rock, Arkansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.3 °F (low) to 70.6 °F (high). Annual precipitation averages 50.7 Inches. Sulphur Rock 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 | 28.7 °F | 47.5 °F | 3.72 in. |
| February | 31.5 °F | 52.1 °F | 3.92 in. |
| March | 39.4 °F | 61.1 °F | 4.67 in. |
| April | 48.4 °F | 71.1 °F | 5.26 in. |
| May | 58.4 °F | 79.4 °F | 5.21 in. |
| June | 66.9 °F | 87.4 °F | 3.64 in. |
| July | 70.4 °F | 91.1 °F | 3.78 in. |
| August | 68.3 °F | 90.5 °F | 3.53 in. |
| September | 60.6 °F | 83.9 °F | 3.4 in. |
| October | 48.8 °F | 73.0 °F | 3.88 in. |
| November | 38.9 °F | 60.3 °F | 4.84 in. |
| December | 31.5 °F | 50.1 °F | 4.81 in. |
| Annual | 49.3 °F | 70.6 °F | 50.66 in. |
| 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 : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |