South Haven, Michigan has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 42.2 °F (low) to 56.5 °F (high). Annual precipitation averages 35.4 Inches. South Haven is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.7 °F | 32.1 °F | 2.66 in. |
| February | 21.9 °F | 34.4 °F | 2.03 in. |
| March | 28.2 °F | 42.9 °F | 1.86 in. |
| April | 38.1 °F | 54.6 °F | 3.43 in. |
| May | 48.8 °F | 65.1 °F | 3.71 in. |
| June | 58.5 °F | 74.3 °F | 3.32 in. |
| July | 63.5 °F | 78.6 °F | 2.88 in. |
| August | 63.1 °F | 77.8 °F | 3.51 in. |
| September | 56.2 °F | 72.3 °F | 3.21 in. |
| October | 45.0 °F | 61.1 °F | 3.47 in. |
| November | 35.2 °F | 47.9 °F | 2.84 in. |
| December | 26.8 °F | 37.2 °F | 2.49 in. |
| Annual | 42.2 °F | 56.5 °F | 35.41 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |