Formoso, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.2 °C (low) to 18.3 °C (high). Annual precipitation averages 723.4 Millimeters. Formoso 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 | -8.6 °C | 3.4 °C | 16.51 mm |
| February | -6.7 °C | 5.9 °C | 21.34 mm |
| March | -1.5 °C | 12.4 °C | 38.61 mm |
| April | 4.1 °C | 18.2 °C | 64.01 mm |
| May | 10.5 °C | 23.5 °C | 110.74 mm |
| June | 16.7 °C | 29.5 °C | 105.92 mm |
| July | 19.2 °C | 32.2 °C | 111 mm |
| August | 18 °C | 30.8 °C | 86.11 mm |
| September | 12.8 °C | 26.8 °C | 62.48 mm |
| October | 5.6 °C | 19.8 °C | 50.55 mm |
| November | -1.5 °C | 11.6 °C | 31.24 mm |
| December | -6.7 °C | 4.9 °C | 24.89 mm |
| Annual | 5.2 °C | 18.3 °C | 723.4 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |