Plainfield, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.7 °F (low) to 62.5 °F (high). Annual precipitation averages 45.6 Inches. Plainfield is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.2 °F | 35.8 °F | 3.11 in. |
| February | 23.1 °F | 40.1 °F | 2.63 in. |
| March | 31.7 °F | 50.9 °F | 3.52 in. |
| April | 42.5 °F | 63.5 °F | 4.69 in. |
| May | 53.5 °F | 73.2 °F | 4.94 in. |
| June | 62.4 °F | 81.8 °F | 5.26 in. |
| July | 65.6 °F | 84.9 °F | 4.81 in. |
| August | 64.1 °F | 83.9 °F | 3.3 in. |
| September | 56.5 °F | 78.3 °F | 3.5 in. |
| October | 44.8 °F | 65.9 °F | 3.42 in. |
| November | 34.1 °F | 51.9 °F | 3.32 in. |
| December | 25.6 °F | 40.3 °F | 3.09 in. |
| Annual | 43.7 °F | 62.5 °F | 45.59 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |