Monroe, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.1 °C (low) to 24.7 °C (high). Annual precipitation averages 1444.8 Millimeters. Monroe is located in USDA Plant Hardiness Zone 8b. 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 | 1.8 °C | 13.5 °C | 139.19 mm |
| February | 3.4 °C | 16.1 °C | 127.51 mm |
| March | 7.4 °C | 20.4 °C | 141.48 mm |
| April | 11.5 °C | 24.8 °C | 151.13 mm |
| May | 16.8 °C | 29 °C | 125.48 mm |
| June | 20.8 °C | 32.5 °C | 109.73 mm |
| July | 22.4 °C | 33.9 °C | 103.38 mm |
| August | 21.8 °C | 34.4 °C | 88.9 mm |
| September | 18.2 °C | 31.7 °C | 88.9 mm |
| October | 11.8 °C | 26.2 °C | 111.25 mm |
| November | 6.3 °C | 19.5 °C | 119.38 mm |
| December | 2.9 °C | 14.9 °C | 138.43 mm |
| Annual | 12.1 °C | 24.7 °C | 1444.76 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 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |