Blair, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34 °F (low) to 55.8 °F (high). Annual precipitation averages 35.2 Inches. Blair 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.2 °F | 24.9 °F | 1.02 in. |
| February | 8.7 °F | 29.9 °F | 1.03 in. |
| March | 20.8 °F | 42.4 °F | 1.85 in. |
| April | 33.0 °F | 56.5 °F | 3.43 in. |
| May | 45.2 °F | 69.2 °F | 4.53 in. |
| June | 55.6 °F | 78.3 °F | 5.37 in. |
| July | 59.3 °F | 82.3 °F | 4.02 in. |
| August | 57.1 °F | 80.3 °F | 4.11 in. |
| September | 48.7 °F | 72.8 °F | 4.19 in. |
| October | 36.5 °F | 59.2 °F | 2.66 in. |
| November | 25.1 °F | 43.4 °F | 1.76 in. |
| December | 12.7 °F | 30.3 °F | 1.26 in. |
| Annual | 34 °F | 55.8 °F | 35.23 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 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 | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |