Haslett, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.1 °F (low) to 57.1 °F (high). Annual precipitation averages 34.5 Inches. Haslett 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 | 15.7 °F | 30.1 °F | 2.24 in. |
| February | 16.3 °F | 32.9 °F | 1.87 in. |
| March | 24.6 °F | 43.3 °F | 2.07 in. |
| April | 35.7 °F | 56.2 °F | 3.36 in. |
| May | 47.1 °F | 68.2 °F | 3.89 in. |
| June | 56.5 °F | 77.6 °F | 3.68 in. |
| July | 59.7 °F | 81.2 °F | 3.18 in. |
| August | 58.1 °F | 79.4 °F | 3.31 in. |
| September | 50.6 °F | 73.4 °F | 3.11 in. |
| October | 39.8 °F | 60.2 °F | 3.13 in. |
| November | 30.5 °F | 46.9 °F | 2.56 in. |
| December | 22.3 °F | 35.3 °F | 2.07 in. |
| Annual | 38.1 °F | 57.1 °F | 34.47 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 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 | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |