Mason, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.5 °C (low) to 10.9 °C (high). Annual precipitation averages 835.2 Millimeters. Mason is located in USDA Plant Hardiness Zone 4b. 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 | -15.8 °C | -5.7 °C | 31.75 mm |
| February | -14.5 °C | -3 °C | 26.92 mm |
| March | -8.5 °C | 3.2 °C | 41.66 mm |
| April | -1.7 °C | 10.1 °C | 72.64 mm |
| May | 4.4 °C | 17.8 °C | 95 mm |
| June | 10.2 °C | 23.1 °C | 103.38 mm |
| July | 13.2 °C | 25.8 °C | 110.74 mm |
| August | 12.3 °C | 24.9 °C | 92.46 mm |
| September | 8.3 °C | 20.7 °C | 90.68 mm |
| October | 1.8 °C | 12.7 °C | 83.06 mm |
| November | -4.4 °C | 4.4 °C | 47.5 mm |
| December | -11.3 °C | -2.8 °C | 39.37 mm |
| Annual | -0.5 °C | 10.9 °C | 835.16 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |