| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F Zone 4b: -25°F to -20°F Zone 6a: -10°F to -5°F Zone 4a: -30°F to -25°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 5b: -15°F to -10°F Zone 4b: -25°F to -20°F Zone 6a: -10°F to -5°F Zone 4a: -30°F to -25°F |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F |
| Average First Frost Date: | Sep.1 - Sep. 10 |
| Average Last Frost Date: | Jun. 1 - Jun. 10 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 21d - Foothills and Shrublands |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 80540 - Lyons, CO | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 15 | 18 | 24 | 31 | 40 | 48 | 53 | 52 | 43 | 33 | 24 | 16 | 33 |
| Avg Max Temp (°F) | 41 | 45 | 51 | 59 | 69 | 79 | 86 | 83 | 75 | 64 | 49 | 43 | 62 |
| Avg Precip (In.) | .56 | .54 | 1.4 | 2.35 | 2.96 | 1.91 | 1.76 | 1.63 | 1.5 | 1.06 | .96 | .6 | 17.24 |