Littleton, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 37.8 °F (low) to 65.5 °F (high). Annual precipitation averages 16.5 Inches. Littleton is located in USDA Plant Hardiness Zone 6a. 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 | 19.7 °F | 46.8 °F | 0.47 in. |
| February | 20.9 °F | 47.8 °F | 0.6 in. |
| March | 28.8 °F | 56.4 °F | 1.31 in. |
| April | 35.2 °F | 62.0 °F | 2.14 in. |
| May | 44.3 °F | 70.6 °F | 2.36 in. |
| June | 54.0 °F | 82.6 °F | 1.82 in. |
| July | 60.0 °F | 88.7 °F | 2.01 in. |
| August | 58.1 °F | 86.3 °F | 1.88 in. |
| September | 49.3 °F | 78.7 °F | 1.45 in. |
| October | 36.7 °F | 65.6 °F | 1.16 in. |
| November | 27.0 °F | 54.5 °F | 0.78 in. |
| December | 19.2 °F | 45.9 °F | 0.53 in. |
| Annual | 37.8 °F | 65.5 °F | 16.51 in. |
| 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 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |