Grand Lake, Colorado has a Subarctic With Cool Summers And Year Around Rainfall climate (Köppen classification: Dfc). Average annual temperatures range from 23 °F (low) to 52.8 °F (high). Annual precipitation averages 18.1 Inches. Grand Lake is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around Jun. 11 - Jun. 20 through the first frost around Aug. 11 - Aug. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.2 °F | 29.8 °F | 1.53 in. |
| February | 5.4 °F | 33.2 °F | 1.46 in. |
| March | 13.3 °F | 41.9 °F | 1.27 in. |
| April | 21.7 °F | 49.8 °F | 1.56 in. |
| May | 29.5 °F | 60.1 °F | 1.77 in. |
| June | 36.2 °F | 71.3 °F | 1.33 in. |
| July | 42.2 °F | 76.9 °F | 1.79 in. |
| August | 41.0 °F | 74.8 °F | 2.01 in. |
| September | 34.0 °F | 68.3 °F | 1.53 in. |
| October | 25.5 °F | 55.8 °F | 1.25 in. |
| November | 16.1 °F | 41.1 °F | 1.23 in. |
| December | 7.0 °F | 30.4 °F | 1.41 in. |
| Annual | 23 °F | 52.8 °F | 18.14 in. |
| Average First Frost Date | Aug. 11 - Aug. 20 |
| Average Last Frost Date | Jun. 11 - Jun. 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Dfc - Subarctic With Cool Summers And Year Around Rainfall |