Flagstaff, Arizona has a Humid Continental Climate - Dry Cool Summer climate (Köppen classification: Dsb). Average annual temperatures range from 32.1 °F (low) to 63.4 °F (high). Annual precipitation averages 19.7 Inches. Flagstaff is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Jun. 1 - Jun. 10 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.3 °F | 44.7 °F | 1.78 in. |
| February | 19.8 °F | 47.3 °F | 2.09 in. |
| March | 24.1 °F | 53.6 °F | 1.8 in. |
| April | 28.4 °F | 60.3 °F | 1.15 in. |
| May | 35.2 °F | 69.4 °F | 0.7 in. |
| June | 43.4 °F | 80.7 °F | 0.32 in. |
| July | 51.6 °F | 83.7 °F | 2.44 in. |
| August | 50.5 °F | 80.9 °F | 3.03 in. |
| September | 42.8 °F | 75.8 °F | 1.86 in. |
| October | 31.7 °F | 65.4 °F | 1.31 in. |
| November | 23.1 °F | 53.9 °F | 1.49 in. |
| December | 17.1 °F | 44.6 °F | 1.69 in. |
| Annual | 32.1 °F | 63.4 °F | 19.66 in. |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | Jun. 1 - Jun. 10 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dsb - Humid Continental Climate - Dry Cool Summer |