Sparta, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.8 °F (low) to 56.1 °F (high). Annual precipitation averages 35.7 Inches. Sparta 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 Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.1 °F | 25.8 °F | 1.08 in. |
| February | 10.2 °F | 30.6 °F | 1.12 in. |
| March | 21.9 °F | 42.7 °F | 1.79 in. |
| April | 33.9 °F | 56.5 °F | 3.67 in. |
| May | 45.7 °F | 69.0 °F | 4.62 in. |
| June | 55.7 °F | 78.6 °F | 5.44 in. |
| July | 59.6 °F | 82.4 °F | 4.2 in. |
| August | 57.2 °F | 80.3 °F | 4.29 in. |
| September | 48.6 °F | 72.7 °F | 3.76 in. |
| October | 37.0 °F | 59.3 °F | 2.59 in. |
| November | 25.8 °F | 43.8 °F | 1.73 in. |
| December | 14.4 °F | 31.0 °F | 1.45 in. |
| Annual | 34.8 °F | 56.1 °F | 35.74 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 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |