East Gillespie, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 44 °F (low) to 63.6 °F (high). Annual precipitation averages 41.9 Inches. East Gillespie is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.4 °F | 36.1 °F | 2.51 in. |
| February | 23.8 °F | 41.4 °F | 2.21 in. |
| March | 32.8 °F | 52.4 °F | 3.09 in. |
| April | 43.2 °F | 64.5 °F | 4.74 in. |
| May | 54.3 °F | 74.3 °F | 4.98 in. |
| June | 63.3 °F | 83.0 °F | 4.33 in. |
| July | 66.4 °F | 86.0 °F | 3.94 in. |
| August | 64.2 °F | 85.1 °F | 3.44 in. |
| September | 55.7 °F | 79.5 °F | 3.33 in. |
| October | 44.4 °F | 67.4 °F | 3.25 in. |
| November | 34.3 °F | 52.7 °F | 3.47 in. |
| December | 25.4 °F | 41.0 °F | 2.56 in. |
| Annual | 44 °F | 63.6 °F | 41.85 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |