Williamsburg, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 2.9 °C (low) to 19.5 °C (high). Annual precipitation averages 336.8 Millimeters. Williamsburg is located in USDA Plant Hardiness Zone 6a. 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 | -7.1 °C | 8.8 °C | 16.26 mm |
| February | -6.6 °C | 9.4 °C | 9.91 mm |
| March | -2.7 °C | 14.3 °C | 26.92 mm |
| April | 1.2 °C | 18 °C | 43.43 mm |
| May | 6.6 °C | 22.9 °C | 50.8 mm |
| June | 11.7 °C | 29.2 °C | 23.88 mm |
| July | 15 °C | 31.7 °C | 47.5 mm |
| August | 14.1 °C | 30.2 °C | 44.45 mm |
| September | 9.4 °C | 26.7 °C | 30.99 mm |
| October | 2.4 °C | 20.3 °C | 20.07 mm |
| November | -2.7 °C | 13.4 °C | 14.48 mm |
| December | -6.7 °C | 8.7 °C | 8.13 mm |
| Annual | 2.9 °C | 19.5 °C | 336.82 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 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |