Ashburn, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.6 °C (low) to 17.9 °C (high). Annual precipitation averages 983.2 Millimeters. Ashburn 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 | -6.9 °C | 2.5 °C | 50.55 mm |
| February | -5.1 °C | 5.3 °C | 49.78 mm |
| March | 0.1 °C | 11.4 °C | 69.85 mm |
| April | 6.1 °C | 18.3 °C | 103.63 mm |
| May | 12.1 °C | 23.9 °C | 119.13 mm |
| June | 17.3 °C | 28.8 °C | 113.79 mm |
| July | 19.4 °C | 30.9 °C | 101.6 mm |
| August | 18.3 °C | 30.3 °C | 86.11 mm |
| September | 13.7 °C | 26.4 °C | 89.15 mm |
| October | 7.4 °C | 19.7 °C | 75.44 mm |
| November | 1.1 °C | 11.9 °C | 70.1 mm |
| December | -4.2 °C | 5.2 °C | 54.1 mm |
| Annual | 6.6 °C | 17.9 °C | 983.23 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 |