Pittsfield, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.9 °F (low) to 62.9 °F (high). Annual precipitation averages 39.4 Inches. Pittsfield is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.4 °F | 35.2 °F | 1.97 in. |
| February | 21.9 °F | 40.3 °F | 1.98 in. |
| March | 31.4 °F | 51.5 °F | 2.75 in. |
| April | 42.1 °F | 64.0 °F | 4.16 in. |
| May | 53.3 °F | 73.6 °F | 4.7 in. |
| June | 62.7 °F | 82.2 °F | 4.81 in. |
| July | 65.9 °F | 85.7 °F | 4.31 in. |
| August | 63.8 °F | 84.8 °F | 3.44 in. |
| September | 55.1 °F | 78.9 °F | 3.57 in. |
| October | 43.7 °F | 66.3 °F | 2.79 in. |
| November | 33.2 °F | 52.3 °F | 2.84 in. |
| December | 23.6 °F | 39.9 °F | 2.06 in. |
| Annual | 42.9 °F | 62.9 °F | 39.38 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 |