Simpson, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.9 °C (low) to 19.3 °C (high). Annual precipitation averages 727.7 Millimeters. Simpson is located in USDA Plant Hardiness Zone 6b. 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 | -7.7 °C | 4.4 °C | 17.53 mm |
| February | -5.9 °C | 7 °C | 23.62 mm |
| March | -0.8 °C | 13.4 °C | 39.62 mm |
| April | 4.8 °C | 19.1 °C | 62.48 mm |
| May | 11.2 °C | 24.4 °C | 113.28 mm |
| June | 17.2 °C | 30.7 °C | 103.63 mm |
| July | 20 °C | 33.6 °C | 110.74 mm |
| August | 18.7 °C | 32 °C | 88.65 mm |
| September | 13.7 °C | 27.9 °C | 65.79 mm |
| October | 6.2 °C | 20.8 °C | 47.5 mm |
| November | -0.8 °C | 12.4 °C | 28.7 mm |
| December | -5.9 °C | 5.7 °C | 26.16 mm |
| Annual | 5.9 °C | 19.3 °C | 727.7 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 6b : -20.6°C to -17.8°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 |