McNary, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 55.7 °F (low) to 77.7 °F (high). Annual precipitation averages 61.3 Inches. McNary is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 38.0 °F | 59.5 °F | 6.3 in. |
| February | 41.5 °F | 63.7 °F | 4.95 in. |
| March | 48.1 °F | 71.0 °F | 4.59 in. |
| April | 55.0 °F | 77.8 °F | 5.2 in. |
| May | 63.6 °F | 84.8 °F | 4.99 in. |
| June | 70.1 °F | 90.3 °F | 5.29 in. |
| July | 72.5 °F | 92.4 °F | 4.77 in. |
| August | 71.9 °F | 93.2 °F | 4.58 in. |
| September | 66.6 °F | 88.7 °F | 4.64 in. |
| October | 55.2 °F | 80.0 °F | 4.83 in. |
| November | 45.4 °F | 69.2 °F | 5.49 in. |
| December | 40.0 °F | 61.6 °F | 5.68 in. |
| Annual | 55.7 °F | 77.7 °F | 61.31 in. |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |