Fitchburg, Wisconsin has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.5 °F (low) to 56.4 °F (high). Annual precipitation averages 38.6 Inches. Fitchburg is located in USDA Plant Hardiness Zone 5b. 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 | 10.9 °F | 26.9 °F | 1.53 in. |
| February | 14.4 °F | 30.9 °F | 1.59 in. |
| March | 24.5 °F | 43.0 °F | 2.16 in. |
| April | 35.9 °F | 56.7 °F | 3.88 in. |
| May | 47.8 °F | 68.8 °F | 4.48 in. |
| June | 57.6 °F | 78.0 °F | 5.66 in. |
| July | 61.8 °F | 81.7 °F | 4.49 in. |
| August | 60.1 °F | 80.1 °F | 4.29 in. |
| September | 51.5 °F | 73.1 °F | 3.6 in. |
| October | 40.0 °F | 60.4 °F | 2.91 in. |
| November | 28.2 °F | 44.8 °F | 2.26 in. |
| December | 17.7 °F | 32.5 °F | 1.74 in. |
| Annual | 37.5 °F | 56.4 °F | 38.59 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |