Glenwood, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.8 °C (low) to 16.1 °C (high). Annual precipitation averages 1008.9 Millimeters. Glenwood is located in USDA Plant Hardiness Zone 5b. 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 | -9.7 °C | 0.2 °C | 30.73 mm |
| February | -7.7 °C | 2.8 °C | 37.08 mm |
| March | -1.8 °C | 9.9 °C | 56.9 mm |
| April | 4.3 °C | 16.7 °C | 97.28 mm |
| May | 10.7 °C | 22.1 °C | 144.02 mm |
| June | 16.2 °C | 27.3 °C | 134.11 mm |
| July | 18.3 °C | 29.6 °C | 119.89 mm |
| August | 17.2 °C | 28.8 °C | 114.55 mm |
| September | 12.3 °C | 24.9 °C | 101.09 mm |
| October | 5.6 °C | 17.9 °C | 74.68 mm |
| November | -1.1 °C | 9.9 °C | 58.17 mm |
| December | -6.6 °C | 2.9 °C | 40.39 mm |
| Annual | 4.8 °C | 16.1 °C | 1008.89 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 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |