Two Harbors, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.2 °C (low) to 9.6 °C (high). Annual precipitation averages 788.4 Millimeters. Two Harbors 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 | -14.7 °C | -5.3 °C | 26.92 mm |
| February | -13.6 °C | -2.9 °C | 26.67 mm |
| March | -7.5 °C | 2.1 °C | 36.32 mm |
| April | -0.8 °C | 8 °C | 66.55 mm |
| May | 4.1 °C | 14.2 °C | 82.55 mm |
| June | 8.6 °C | 19.2 °C | 105.66 mm |
| July | 13.4 °C | 23.8 °C | 99.31 mm |
| August | 13.6 °C | 23.4 °C | 89.92 mm |
| September | 9.4 °C | 19 °C | 86.87 mm |
| October | 3.4 °C | 11.8 °C | 76.2 mm |
| November | -3.6 °C | 4.2 °C | 52.07 mm |
| December | -10.5 °C | -2.6 °C | 39.37 mm |
| Annual | 0.2 °C | 9.6 °C | 788.41 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |