Fleming, Colorado has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 1.9 °C (low) to 17.8 °C (high). Annual precipitation averages 440.7 Millimeters. Fleming 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 Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.1 °C | 5.2 °C | 7.62 mm |
| February | -8.3 °C | 6.3 °C | 10.92 mm |
| March | -3.9 °C | 12.1 °C | 21.34 mm |
| April | 0.1 °C | 16.3 °C | 45.72 mm |
| May | 6.1 °C | 21.4 °C | 74.17 mm |
| June | 11.8 °C | 28.3 °C | 65.28 mm |
| July | 15.3 °C | 32.3 °C | 72.39 mm |
| August | 13.8 °C | 30.8 °C | 56.39 mm |
| September | 8.9 °C | 26.4 °C | 35.05 mm |
| October | 1.6 °C | 18.3 °C | 30.23 mm |
| November | -4.2 °C | 11.1 °C | 11.68 mm |
| December | -8.9 °C | 5.2 °C | 9.91 mm |
| Annual | 1.9 °C | 17.8 °C | 440.7 mm |
| 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 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |