Alsey, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.9 °C (low) to 17.5 °C (high). Annual precipitation averages 1023.6 Millimeters. Alsey 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.5 °C | 2 °C | 55.63 mm |
| February | -5.6 °C | 4.9 °C | 52.07 mm |
| March | -0.5 °C | 11.2 °C | 74.93 mm |
| April | 5.3 °C | 18.1 °C | 106.43 mm |
| May | 11.7 °C | 23.5 °C | 124.21 mm |
| June | 16.9 °C | 28.3 °C | 129.03 mm |
| July | 18.7 °C | 30.1 °C | 100.84 mm |
| August | 17.3 °C | 29.5 °C | 86.11 mm |
| September | 12.6 °C | 26.3 °C | 84.07 mm |
| October | 6.2 °C | 19.4 °C | 75.95 mm |
| November | 0.4 °C | 11.5 °C | 76.71 mm |
| December | -4.6 °C | 4.7 °C | 57.66 mm |
| Annual | 5.9 °C | 17.5 °C | 1023.64 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |