Rockport, Indiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.1 °C (low) to 19.7 °C (high). Annual precipitation averages 1247.9 Millimeters. Rockport is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.7 °C | 5.6 °C | 92.2 mm |
| February | -2.6 °C | 8.1 °C | 90.17 mm |
| March | 1.9 °C | 13.6 °C | 113.79 mm |
| April | 7.6 °C | 20.2 °C | 126.75 mm |
| May | 13.3 °C | 25.3 °C | 133.35 mm |
| June | 18.1 °C | 29.7 °C | 113.54 mm |
| July | 19.9 °C | 31.3 °C | 108.71 mm |
| August | 18.7 °C | 31 °C | 78.23 mm |
| September | 14.6 °C | 27.9 °C | 91.44 mm |
| October | 8.2 °C | 21.6 °C | 92.2 mm |
| November | 2.3 °C | 13.7 °C | 98.81 mm |
| December | -1.6 °C | 7.9 °C | 108.71 mm |
| Annual | 8.1 °C | 19.7 °C | 1247.9 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |