Fort Garland, Colorado has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -2.5 °C (low) to 14.8 °C (high). Annual precipitation averages 286.5 Millimeters. Fort Garland is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15.1 °C | 1.6 °C | 10.16 mm |
| February | -11 °C | 4.4 °C | 9.4 mm |
| March | -6.2 °C | 10.1 °C | 19.56 mm |
| April | -2.9 °C | 14.2 °C | 22.35 mm |
| May | 1.8 °C | 19.3 °C | 27.94 mm |
| June | 6.5 °C | 25.2 °C | 35.81 mm |
| July | 9.3 °C | 27.2 °C | 45.21 mm |
| August | 8.3 °C | 25.8 °C | 39.37 mm |
| September | 4.2 °C | 22.7 °C | 30.73 mm |
| October | -2.1 °C | 16.3 °C | 21.59 mm |
| November | -8.5 °C | 8.6 °C | 12.45 mm |
| December | -14 °C | 2.1 °C | 11.94 mm |
| Annual | -2.5 °C | 14.8 °C | 286.51 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |