Dunkirk, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.5 °F (low) to 61 °F (high). Annual precipitation averages 41.4 Inches. Dunkirk 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 | 18.1 °F | 33.7 °F | 2.76 in. |
| February | 20.7 °F | 37.8 °F | 2.33 in. |
| March | 29.4 °F | 48.4 °F | 3.21 in. |
| April | 39.9 °F | 61.4 °F | 4.0 in. |
| May | 51.0 °F | 72.2 °F | 4.35 in. |
| June | 60.7 °F | 80.8 °F | 4.56 in. |
| July | 63.2 °F | 83.8 °F | 4.22 in. |
| August | 61.1 °F | 82.3 °F | 3.87 in. |
| September | 53.7 °F | 77.1 °F | 3.28 in. |
| October | 42.9 °F | 64.8 °F | 2.94 in. |
| November | 32.7 °F | 50.6 °F | 3.22 in. |
| December | 24.3 °F | 38.7 °F | 2.7 in. |
| Annual | 41.5 °F | 61 °F | 41.44 in. |
| 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 : -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 |