Alton, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.9 °F (low) to 66.8 °F (high). Annual precipitation averages 26.7 Inches. Alton is located in USDA Plant Hardiness Zone 6a. 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 | 16.0 °F | 40.4 °F | 0.61 in. |
| February | 18.8 °F | 44.7 °F | 0.74 in. |
| March | 27.9 °F | 56.1 °F | 1.45 in. |
| April | 37.7 °F | 66.2 °F | 2.27 in. |
| May | 49.3 °F | 75.6 °F | 4.0 in. |
| June | 60.7 °F | 87.1 °F | 3.72 in. |
| July | 65.8 °F | 92.6 °F | 4.41 in. |
| August | 63.5 °F | 89.7 °F | 3.57 in. |
| September | 53.9 °F | 82.1 °F | 2.09 in. |
| October | 39.8 °F | 69.4 °F | 1.78 in. |
| November | 27.3 °F | 54.6 °F | 1.13 in. |
| December | 18.3 °F | 42.7 °F | 0.96 in. |
| Annual | 39.9 °F | 66.8 °F | 26.73 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 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |