Rockville, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.8 °C (low) to 17.3 °C (high). Annual precipitation averages 1148.4 Millimeters. Rockville 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 °C | 1.9 °C | 77.98 mm |
| February | -5.4 °C | 4.6 °C | 65.53 mm |
| March | -0.4 °C | 10.8 °C | 84.84 mm |
| April | 5.3 °C | 18.1 °C | 119.13 mm |
| May | 11.2 °C | 23.7 °C | 125.48 mm |
| June | 16.3 °C | 28.4 °C | 129.29 mm |
| July | 17.9 °C | 29.9 °C | 113.54 mm |
| August | 16.7 °C | 29.2 °C | 90.17 mm |
| September | 12.4 °C | 26.2 °C | 81.28 mm |
| October | 6.2 °C | 19.4 °C | 93.73 mm |
| November | 0.6 °C | 11.1 °C | 92.96 mm |
| December | -4.3 °C | 4.4 °C | 74.42 mm |
| Annual | 5.8 °C | 17.3 °C | 1148.35 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 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |