Arco, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.2 °F (low) to 53.6 °F (high). Annual precipitation averages 27.3 Inches. Arco is located in USDA Plant Hardiness Zone 5a. 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 | 5.4 °F | 22.4 °F | 0.7 in. |
| February | 9.2 °F | 26.9 °F | 0.86 in. |
| March | 20.8 °F | 38.7 °F | 1.41 in. |
| April | 32.8 °F | 53.5 °F | 2.79 in. |
| May | 45.9 °F | 66.7 °F | 3.43 in. |
| June | 56.8 °F | 76.9 °F | 4.0 in. |
| July | 60.9 °F | 81.1 °F | 3.6 in. |
| August | 58.2 °F | 78.8 °F | 3.25 in. |
| September | 49.7 °F | 72.1 °F | 3.12 in. |
| October | 36.2 °F | 57.5 °F | 2.04 in. |
| November | 23.1 °F | 41.1 °F | 1.12 in. |
| December | 11.5 °F | 27.4 °F | 1.02 in. |
| Annual | 34.2 °F | 53.6 °F | 27.34 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |