Middletown, 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 16.2 °C (high). Annual precipitation averages 1103.9 Millimeters. Middletown is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.7 °C | 1.2 °C | 76.45 mm |
| February | -6.3 °C | 3.3 °C | 61.98 mm |
| March | -1.4 °C | 9.3 °C | 85.34 mm |
| April | 4.3 °C | 16.4 °C | 108.97 mm |
| May | 10.6 °C | 22.5 °C | 117.09 mm |
| June | 15.7 °C | 27.2 °C | 133.1 mm |
| July | 16.9 °C | 28.8 °C | 112.78 mm |
| August | 16 °C | 28.2 °C | 84.58 mm |
| September | 11.8 °C | 25.3 °C | 80.26 mm |
| October | 5.8 °C | 18.3 °C | 80.77 mm |
| November | 0.2 °C | 10.4 °C | 86.11 mm |
| December | -4.4 °C | 3.8 °C | 76.45 mm |
| Annual | 5.1 °C | 16.2 °C | 1103.88 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| 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 |