Gary, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.2 °F (low) to 59.6 °F (high). Annual precipitation averages 40.4 Inches. Gary 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 | 19.1 °F | 32.8 °F | 2.37 in. |
| February | 21.8 °F | 36.4 °F | 1.96 in. |
| March | 30.3 °F | 46.4 °F | 2.38 in. |
| April | 40.2 °F | 58.5 °F | 3.62 in. |
| May | 50.7 °F | 69.3 °F | 4.33 in. |
| June | 60.6 °F | 79.1 °F | 4.45 in. |
| July | 66.1 °F | 83.3 °F | 4.31 in. |
| August | 65.3 °F | 81.9 °F | 4.08 in. |
| September | 57.8 °F | 76.1 °F | 3.41 in. |
| October | 46.1 °F | 63.5 °F | 4.03 in. |
| November | 35.1 °F | 49.8 °F | 3.1 in. |
| December | 24.9 °F | 37.9 °F | 2.34 in. |
| Annual | 43.2 °F | 59.6 °F | 40.38 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 |