Monroe, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.1 °C (low) to 15.9 °C (high). Annual precipitation averages 1030.5 Millimeters. Monroe is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.7 °C | 0.6 °C | 68.33 mm |
| February | -6.6 °C | 2.7 °C | 57.66 mm |
| March | -1.9 °C | 8.7 °C | 70.87 mm |
| April | 3.9 °C | 16 °C | 100.58 mm |
| May | 10.2 °C | 22.2 °C | 115.06 mm |
| June | 15.8 °C | 27.2 °C | 113.54 mm |
| July | 17.5 °C | 29.1 °C | 113.54 mm |
| August | 16.2 °C | 28.1 °C | 99.57 mm |
| September | 12.1 °C | 24.9 °C | 78.49 mm |
| October | 6 °C | 18.1 °C | 73.15 mm |
| November | 0.3 °C | 9.9 °C | 76.45 mm |
| December | -4.5 °C | 3.3 °C | 63.25 mm |
| Annual | 5.1 °C | 15.9 °C | 1030.49 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |