Pittsburg, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.1 °F (low) to 66.4 °F (high). Annual precipitation averages 48.1 Inches. Pittsburg is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 24.0 °F | 41.0 °F | 3.66 in. |
| February | 27.1 °F | 46.0 °F | 3.07 in. |
| March | 35.5 °F | 55.9 °F | 4.54 in. |
| April | 45.6 °F | 67.4 °F | 5.45 in. |
| May | 55.9 °F | 76.0 °F | 5.09 in. |
| June | 64.4 °F | 84.4 °F | 4.46 in. |
| July | 67.9 °F | 87.4 °F | 4.04 in. |
| August | 65.5 °F | 86.8 °F | 3.11 in. |
| September | 57.5 °F | 81.0 °F | 3.16 in. |
| October | 45.9 °F | 69.7 °F | 3.51 in. |
| November | 35.8 °F | 56.3 °F | 4.38 in. |
| December | 28.0 °F | 45.2 °F | 3.61 in. |
| Annual | 46.1 °F | 66.4 °F | 48.08 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |