Martinton, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.5 °F (low) to 61 °F (high). Annual precipitation averages 39 Inches. Martinton 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 | 16.2 °F | 32.2 °F | 2.18 in. |
| February | 19.3 °F | 36.8 °F | 1.95 in. |
| March | 28.8 °F | 48.5 °F | 2.44 in. |
| April | 38.8 °F | 61.9 °F | 3.7 in. |
| May | 50.4 °F | 72.8 °F | 4.37 in. |
| June | 60.1 °F | 81.7 °F | 4.88 in. |
| July | 63.3 °F | 84.4 °F | 4.49 in. |
| August | 61.0 °F | 82.9 °F | 3.62 in. |
| September | 53.0 °F | 78.1 °F | 3.19 in. |
| October | 41.8 °F | 65.2 °F | 3.34 in. |
| November | 31.3 °F | 49.9 °F | 2.63 in. |
| December | 21.9 °F | 37.4 °F | 2.2 in. |
| Annual | 40.5 °F | 61 °F | 38.99 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |