Spooner, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.2 °C (low) to 11.7 °C (high). Annual precipitation averages 810.5 Millimeters. Spooner is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -16.6 °C | -5.7 °C | 20.83 mm |
| February | -15 °C | -2.7 °C | 21.59 mm |
| March | -8.1 °C | 4.2 °C | 38.1 mm |
| April | -0.8 °C | 12.3 °C | 71.88 mm |
| May | 6.1 °C | 19.6 °C | 98.04 mm |
| June | 11.7 °C | 24.6 °C | 107.7 mm |
| July | 14.1 °C | 26.8 °C | 107.44 mm |
| August | 12.9 °C | 25.9 °C | 102.11 mm |
| September | 8.6 °C | 21.1 °C | 92.2 mm |
| October | 2.1 °C | 13.4 °C | 79.5 mm |
| November | -4.8 °C | 4.3 °C | 41.4 mm |
| December | -12.1 °C | -2.9 °C | 29.72 mm |
| Annual | -0.2 °C | 11.7 °C | 810.51 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |