Onaga, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6 °C (low) to 18.3 °C (high). Annual precipitation averages 880.1 Millimeters. Onaga 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 | -8 °C | 3.3 °C | 18.8 mm |
| February | -6 °C | 6.2 °C | 30.23 mm |
| March | -0.4 °C | 12.7 °C | 54.1 mm |
| April | 5.3 °C | 18.6 °C | 91.69 mm |
| May | 11.8 °C | 23.7 °C | 124.21 mm |
| June | 17.4 °C | 29 °C | 123.7 mm |
| July | 19.8 °C | 31.5 °C | 113.28 mm |
| August | 18.4 °C | 30.8 °C | 99.57 mm |
| September | 13.3 °C | 26.7 °C | 82.04 mm |
| October | 6.4 °C | 20.1 °C | 70.1 mm |
| November | -0.2 °C | 12.1 °C | 40.64 mm |
| December | -5.6 °C | 5.4 °C | 31.75 mm |
| Annual | 6 °C | 18.3 °C | 880.11 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 |