Blue River, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.5 °C (low) to 14.4 °C (high). Annual precipitation averages 928.4 Millimeters. Blue River 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 | -12.9 °C | -2.4 °C | 32 mm |
| February | -11 °C | 0.2 °C | 32 mm |
| March | -4.8 °C | 7 °C | 51.82 mm |
| April | 2 °C | 14.7 °C | 96.77 mm |
| May | 8.4 °C | 21.4 °C | 111.76 mm |
| June | 14.2 °C | 26.7 °C | 137.92 mm |
| July | 16.4 °C | 28.7 °C | 113.28 mm |
| August | 15.3 °C | 27.7 °C | 101.6 mm |
| September | 10.4 °C | 23.7 °C | 91.69 mm |
| October | 3.6 °C | 16.5 °C | 67.31 mm |
| November | -2.9 °C | 7.7 °C | 52.32 mm |
| December | -8.9 °C | 0.7 °C | 39.88 mm |
| Annual | 2.5 °C | 14.4 °C | 928.35 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 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |