Monterey, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.2 °C (low) to 25.1 °C (high). Annual precipitation averages 1523.7 Millimeters. Monterey is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.3 °C | 14.7 °C | 152.15 mm |
| February | 5.1 °C | 17.2 °C | 133.35 mm |
| March | 9 °C | 21.4 °C | 135.13 mm |
| April | 12.8 °C | 25.2 °C | 132.84 mm |
| May | 17.6 °C | 29.2 °C | 121.16 mm |
| June | 21.3 °C | 32.2 °C | 128.52 mm |
| July | 22.6 °C | 33.4 °C | 117.09 mm |
| August | 22.1 °C | 33.7 °C | 107.7 mm |
| September | 19.3 °C | 31.3 °C | 109.47 mm |
| October | 13 °C | 26.6 °C | 110.49 mm |
| November | 7.4 °C | 20.6 °C | 133.6 mm |
| December | 4.4 °C | 16 °C | 142.24 mm |
| Annual | 13.2 °C | 25.1 °C | 1523.74 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |