Grainfield, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.9 °C (low) to 19 °C (high). Annual precipitation averages 567.9 Millimeters. Grainfield 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 | -8.5 °C | 5.8 °C | 10.41 mm |
| February | -7.2 °C | 7.5 °C | 18.03 mm |
| March | -2.7 °C | 13.3 °C | 31.24 mm |
| April | 2.3 °C | 18.1 °C | 49.78 mm |
| May | 8.6 °C | 23.5 °C | 85.85 mm |
| June | 14.7 °C | 29.9 °C | 78.74 mm |
| July | 17.7 °C | 32.7 °C | 91.44 mm |
| August | 16.6 °C | 31.2 °C | 77.72 mm |
| September | 11.4 °C | 27.1 °C | 42.42 mm |
| October | 3.9 °C | 19.9 °C | 45.47 mm |
| November | -2.8 °C | 12.4 °C | 18.54 mm |
| December | -7.6 °C | 6.4 °C | 18.29 mm |
| Annual | 3.9 °C | 19 °C | 567.93 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 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |