Osawatomie, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.2 °C (low) to 19.2 °C (high). Annual precipitation averages 1019.6 Millimeters. Osawatomie is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.2 °C | 4.9 °C | 31.5 mm |
| February | -4.2 °C | 7.4 °C | 40.39 mm |
| March | 0.9 °C | 13.7 °C | 61.98 mm |
| April | 6.6 °C | 19.4 °C | 98.3 mm |
| May | 12.6 °C | 24.1 °C | 150.37 mm |
| June | 18.1 °C | 29.1 °C | 141.48 mm |
| July | 20.2 °C | 32 °C | 101.85 mm |
| August | 19.1 °C | 31.6 °C | 99.31 mm |
| September | 14.1 °C | 27.4 °C | 115.57 mm |
| October | 7.4 °C | 20.8 °C | 79.5 mm |
| November | 1.2 °C | 13.1 °C | 56.64 mm |
| December | -3.9 °C | 6.8 °C | 42.67 mm |
| Annual | 7.2 °C | 19.2 °C | 1019.56 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 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 |