Glyndon, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.1 °C (low) to 10.9 °C (high). Annual precipitation averages 633.5 Millimeters. Glyndon is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -18.1 °C | -8.5 °C | 18.29 mm |
| February | -15.8 °C | -5.6 °C | 16.76 mm |
| March | -8.2 °C | 1.6 °C | 26.67 mm |
| April | -0.1 °C | 11.6 °C | 37.85 mm |
| May | 7.1 °C | 19.7 °C | 80.52 mm |
| June | 13.3 °C | 24.8 °C | 112.52 mm |
| July | 15.3 °C | 27.1 °C | 90.42 mm |
| August | 13.8 °C | 26.6 °C | 70.36 mm |
| September | 8.8 °C | 21.9 °C | 75.69 mm |
| October | 1.8 °C | 13.2 °C | 61.72 mm |
| November | -6.1 °C | 3.3 °C | 22.35 mm |
| December | -13.5 °C | -4.7 °C | 20.32 mm |
| Annual | -0.1 °C | 10.9 °C | 633.47 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |