Greenbrier, Arkansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.1 °F (low) to 72.2 °F (high). Annual precipitation averages 51.7 Inches. Greenbrier 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 | 28.3 °F | 49.6 °F | 3.42 in. |
| February | 31.2 °F | 54.4 °F | 3.73 in. |
| March | 39.2 °F | 63.4 °F | 5.13 in. |
| April | 48.1 °F | 72.7 °F | 5.41 in. |
| May | 58.1 °F | 80.1 °F | 5.61 in. |
| June | 66.7 °F | 87.9 °F | 3.6 in. |
| July | 70.1 °F | 92.0 °F | 3.7 in. |
| August | 68.7 °F | 91.8 °F | 4.0 in. |
| September | 60.8 °F | 85.2 °F | 3.54 in. |
| October | 48.5 °F | 74.5 °F | 4.27 in. |
| November | 38.2 °F | 61.9 °F | 4.75 in. |
| December | 31.3 °F | 52.4 °F | 4.53 in. |
| Annual | 49.1 °F | 72.2 °F | 51.69 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |