Fairhaven, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.9 °F (low) to 53.2 °F (high). Annual precipitation averages 30 Inches. Fairhaven is located in USDA Plant Hardiness Zone 4b. 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 | 3.6 °F | 21.2 °F | 0.72 in. |
| February | 6.9 °F | 25.8 °F | 0.86 in. |
| March | 19.8 °F | 38.6 °F | 1.5 in. |
| April | 33.1 °F | 53.9 °F | 2.71 in. |
| May | 46.1 °F | 67.2 °F | 3.97 in. |
| June | 56.6 °F | 76.7 °F | 4.29 in. |
| July | 60.8 °F | 80.8 °F | 3.93 in. |
| August | 58.1 °F | 78.7 °F | 4.02 in. |
| September | 49.9 °F | 71.5 °F | 3.06 in. |
| October | 37.2 °F | 56.7 °F | 2.58 in. |
| November | 24.0 °F | 40.2 °F | 1.4 in. |
| December | 11.1 °F | 26.5 °F | 1.0 in. |
| Annual | 33.9 °F | 53.2 °F | 30.04 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 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |