Murphysboro, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.9 °C (low) to 19.2 °C (high). Annual precipitation averages 1194.6 Millimeters. Murphysboro 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 | -4.5 °C | 4.9 °C | 79.25 mm |
| February | -2.6 °C | 7.7 °C | 77.22 mm |
| March | 1.9 °C | 13.3 °C | 108.46 mm |
| April | 7.7 °C | 19.6 °C | 136.4 mm |
| May | 13.4 °C | 24.7 °C | 135.13 mm |
| June | 18.3 °C | 29.6 °C | 118.11 mm |
| July | 20.2 °C | 31.2 °C | 99.06 mm |
| August | 18.7 °C | 30.6 °C | 78.99 mm |
| September | 13.9 °C | 27.3 °C | 77.72 mm |
| October | 7.5 °C | 21.1 °C | 95 mm |
| November | 2.1 °C | 13.4 °C | 101.85 mm |
| December | -2.3 °C | 7.2 °C | 87.38 mm |
| Annual | 7.9 °C | 19.2 °C | 1194.57 mm |
| 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 : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |