Sauget, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.3 °C (low) to 19.3 °C (high). Annual precipitation averages 1129 Millimeters. Sauget 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 Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.9 °C | 4.6 °C | 68.83 mm |
| February | -2.9 °C | 7.6 °C | 60.2 mm |
| March | 1.9 °C | 13.1 °C | 89.15 mm |
| April | 7.9 °C | 19.9 °C | 117.86 mm |
| May | 13.8 °C | 24.9 °C | 132.84 mm |
| June | 18.8 °C | 29.8 °C | 118.87 mm |
| July | 20.9 °C | 31.8 °C | 108.97 mm |
| August | 19.8 °C | 31 °C | 98.55 mm |
| September | 15.1 °C | 27.3 °C | 86.61 mm |
| October | 8.7 °C | 21 °C | 85.09 mm |
| November | 2.6 °C | 13.2 °C | 89.66 mm |
| December | -2.4 °C | 7 °C | 72.39 mm |
| Annual | 8.3 °C | 19.3 °C | 1129.02 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| 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 |