Monroe Center, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.5 °C (low) to 14.4 °C (high). Annual precipitation averages 959.9 Millimeters. Monroe Center is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.8 °C | -2 °C | 42.16 mm |
| February | -8.9 °C | 0.3 °C | 42.67 mm |
| March | -3.3 °C | 7.2 °C | 56.13 mm |
| April | 2.6 °C | 14.8 °C | 92.46 mm |
| May | 9.1 °C | 21.2 °C | 117.6 mm |
| June | 14.6 °C | 26.4 °C | 133.86 mm |
| July | 16.6 °C | 28.1 °C | 101.35 mm |
| August | 15.5 °C | 27.1 °C | 104.65 mm |
| September | 10.8 °C | 23.8 °C | 87.88 mm |
| October | 4.3 °C | 16.7 °C | 72.9 mm |
| November | -1.6 °C | 8.2 °C | 58.93 mm |
| December | -7.4 °C | 1.1 °C | 49.28 mm |
| Annual | 3.5 °C | 14.4 °C | 959.87 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |