Prairie du Sac, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.5 °F (low) to 56.9 °F (high). Annual precipitation averages 36.2 Inches. Prairie du Sac is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 9.8 °F | 27.2 °F | 1.3 in. |
| February | 12.0 °F | 31.6 °F | 1.31 in. |
| March | 23.3 °F | 43.4 °F | 2.0 in. |
| April | 34.9 °F | 57.1 °F | 3.76 in. |
| May | 46.8 °F | 69.3 °F | 4.2 in. |
| June | 57.6 °F | 79.0 °F | 5.46 in. |
| July | 61.2 °F | 82.6 °F | 4.36 in. |
| August | 58.8 °F | 80.7 °F | 4.18 in. |
| September | 50.7 °F | 73.5 °F | 3.45 in. |
| October | 38.9 °F | 60.6 °F | 2.69 in. |
| November | 27.4 °F | 45.3 °F | 2.01 in. |
| December | 16.8 °F | 32.7 °F | 1.52 in. |
| Annual | 36.5 °F | 56.9 °F | 36.24 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |