Niagara, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.5 °C (low) to 11.7 °C (high). Annual precipitation averages 769.6 Millimeters. Niagara 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 | -14.9 °C | -4.6 °C | 33.78 mm |
| February | -14.5 °C | -2.3 °C | 29.46 mm |
| March | -8.9 °C | 3.7 °C | 40.89 mm |
| April | -2.1 °C | 10.8 °C | 68.07 mm |
| May | 4.9 °C | 18.8 °C | 80.52 mm |
| June | 10.5 °C | 24.1 °C | 91.69 mm |
| July | 12.9 °C | 26.6 °C | 87.38 mm |
| August | 12 °C | 25.4 °C | 77.22 mm |
| September | 7.8 °C | 21 °C | 86.61 mm |
| October | 1.4 °C | 13.1 °C | 83.31 mm |
| November | -4.3 °C | 4.9 °C | 48.01 mm |
| December | -10.7 °C | -1.7 °C | 42.67 mm |
| Annual | -0.5 °C | 11.7 °C | 769.61 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |