Lamar, Arkansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.4 °F (low) to 72.1 °F (high). Annual precipitation averages 50.3 Inches. Lamar is located in USDA Plant Hardiness Zone 8a. 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 | 49.6 °F | 3.49 in. |
| February | 32.0 °F | 54.6 °F | 3.09 in. |
| March | 39.5 °F | 63.2 °F | 4.61 in. |
| April | 48.0 °F | 72.5 °F | 5.09 in. |
| May | 57.9 °F | 79.8 °F | 5.39 in. |
| June | 66.6 °F | 87.7 °F | 4.09 in. |
| July | 70.0 °F | 92.3 °F | 3.85 in. |
| August | 69.0 °F | 92.5 °F | 3.59 in. |
| September | 61.3 °F | 85.4 °F | 3.73 in. |
| October | 49.3 °F | 74.2 °F | 4.18 in. |
| November | 38.9 °F | 61.7 °F | 4.99 in. |
| December | 31.4 °F | 51.7 °F | 4.24 in. |
| Annual | 49.4 °F | 72.1 °F | 50.34 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 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |