Westfield, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.4 °F (low) to 61.4 °F (high). Annual precipitation averages 43 Inches. Westfield 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 | 19.2 °F | 34.7 °F | 2.85 in. |
| February | 21.8 °F | 38.7 °F | 2.39 in. |
| March | 30.5 °F | 49.5 °F | 3.27 in. |
| April | 41.2 °F | 62.2 °F | 4.35 in. |
| May | 52.4 °F | 72.5 °F | 4.69 in. |
| June | 61.4 °F | 80.8 °F | 5.16 in. |
| July | 64.3 °F | 83.8 °F | 4.29 in. |
| August | 62.5 °F | 82.6 °F | 3.18 in. |
| September | 54.8 °F | 77.2 °F | 3.36 in. |
| October | 43.5 °F | 65.1 °F | 3.18 in. |
| November | 33.2 °F | 50.9 °F | 3.37 in. |
| December | 24.4 °F | 39.2 °F | 2.94 in. |
| Annual | 42.4 °F | 61.4 °F | 43.03 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 |