Glidden, Iowa has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.1 °C (low) to 14.8 °C (high). Annual precipitation averages 858 Millimeters. Glidden is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.1 °C | -2.2 °C | 21.08 mm |
| February | -9.8 °C | 0.4 °C | 27.94 mm |
| March | -3.7 °C | 7.8 °C | 49.78 mm |
| April | 2.3 °C | 15.6 °C | 89.41 mm |
| May | 9.4 °C | 21.7 °C | 121.67 mm |
| June | 15.3 °C | 27.3 °C | 129.03 mm |
| July | 17.4 °C | 28.9 °C | 103.38 mm |
| August | 15.8 °C | 27.7 °C | 102.62 mm |
| September | 10.7 °C | 24.6 °C | 77.47 mm |
| October | 3.9 °C | 17.3 °C | 65.79 mm |
| November | -3.1 °C | 8.1 °C | 37.85 mm |
| December | -8.8 °C | 0.7 °C | 32 mm |
| Annual | 3.1 °C | 14.8 °C | 858.02 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |