Denison, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.6 °F (low) to 65.4 °F (high). Annual precipitation averages 37.4 Inches. Denison is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.4 °F | 38.3 °F | 0.85 in. |
| February | 22.0 °F | 43.5 °F | 1.2 in. |
| March | 31.9 °F | 55.4 °F | 2.28 in. |
| April | 42.4 °F | 65.7 °F | 3.79 in. |
| May | 53.9 °F | 75.2 °F | 5.38 in. |
| June | 64.0 °F | 84.5 °F | 4.93 in. |
| July | 68.2 °F | 89.1 °F | 4.63 in. |
| August | 66.0 °F | 87.8 °F | 4.4 in. |
| September | 56.6 °F | 80.3 °F | 3.72 in. |
| October | 44.2 °F | 68.2 °F | 3.04 in. |
| November | 32.5 °F | 54.2 °F | 1.86 in. |
| December | 23.0 °F | 42.0 °F | 1.36 in. |
| Annual | 43.6 °F | 65.4 °F | 37.44 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°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 |