Oronoco, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.7 °C (low) to 12.5 °C (high). Annual precipitation averages 897.6 Millimeters. Oronoco 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.4 °C | -4.9 °C | 25.65 mm |
| February | -12.4 °C | -2.3 °C | 27.18 mm |
| March | -5.6 °C | 4.6 °C | 50.04 mm |
| April | 1.3 °C | 12.9 °C | 89.41 mm |
| May | 8.1 °C | 19.9 °C | 111.25 mm |
| June | 13.9 °C | 25.3 °C | 135.13 mm |
| July | 16 °C | 27.3 °C | 109.73 mm |
| August | 14.7 °C | 26.1 °C | 122.43 mm |
| September | 10.2 °C | 22.3 °C | 91.69 mm |
| October | 3.1 °C | 14.8 °C | 61.47 mm |
| November | -3.7 °C | 5.7 °C | 40.89 mm |
| December | -10.3 °C | -1.7 °C | 32.77 mm |
| Annual | 1.7 °C | 12.5 °C | 897.64 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| 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 | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |