Cypress, Illinois has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.5 °C (low) to 19.7 °C (high). Annual precipitation averages 1266.4 Millimeters. Cypress is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.4 °C | 5.9 °C | 95.76 mm |
| February | -1.8 °C | 8.6 °C | 88.39 mm |
| March | 2.7 °C | 13.8 °C | 118.62 mm |
| April | 8.2 °C | 20.2 °C | 135.64 mm |
| May | 13.8 °C | 24.9 °C | 135.89 mm |
| June | 18.5 °C | 29.6 °C | 115.57 mm |
| July | 20.4 °C | 31.3 °C | 100.84 mm |
| August | 19.1 °C | 30.7 °C | 75.18 mm |
| September | 14.7 °C | 27.7 °C | 86.61 mm |
| October | 8.3 °C | 21.7 °C | 96.77 mm |
| November | 2.7 °C | 14.1 °C | 111 mm |
| December | -1.3 °C | 7.9 °C | 106.17 mm |
| Annual | 8.5 °C | 19.7 °C | 1266.44 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| 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 |