Cromwell, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.6 °F (low) to 59.2 °F (high). Annual precipitation averages 38.2 Inches. Cromwell 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 | 17.3 °F | 31.6 °F | 2.44 in. |
| February | 19.4 °F | 35.4 °F | 2.1 in. |
| March | 27.6 °F | 46.7 °F | 2.23 in. |
| April | 38.5 °F | 59.7 °F | 3.62 in. |
| May | 49.8 °F | 70.5 °F | 4.38 in. |
| June | 59.3 °F | 79.6 °F | 4.22 in. |
| July | 62.6 °F | 82.9 °F | 3.82 in. |
| August | 60.7 °F | 80.9 °F | 3.97 in. |
| September | 53.5 °F | 75.3 °F | 3.09 in. |
| October | 42.5 °F | 62.9 °F | 3.15 in. |
| November | 32.3 °F | 48.7 °F | 2.97 in. |
| December | 23.3 °F | 36.5 °F | 2.23 in. |
| Annual | 40.6 °F | 59.2 °F | 38.22 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |