Denison, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.4 °C (low) to 18.5 °C (high). Annual precipitation averages 951 Millimeters. 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 | -7.6 °C | 3.5 °C | 21.59 mm |
| February | -5.6 °C | 6.4 °C | 30.48 mm |
| March | -0.1 °C | 13 °C | 57.91 mm |
| April | 5.8 °C | 18.7 °C | 96.27 mm |
| May | 12.2 °C | 24 °C | 136.65 mm |
| June | 17.8 °C | 29.2 °C | 125.22 mm |
| July | 20.1 °C | 31.7 °C | 117.6 mm |
| August | 18.9 °C | 31 °C | 111.76 mm |
| September | 13.7 °C | 26.8 °C | 94.49 mm |
| October | 6.8 °C | 20.1 °C | 77.22 mm |
| November | 0.3 °C | 12.3 °C | 47.24 mm |
| December | -5 °C | 5.6 °C | 34.54 mm |
| Annual | 6.4 °C | 18.5 °C | 950.97 mm |
| 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 : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |