Siren, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.1 °C (low) to 11.9 °C (high). Annual precipitation averages 820.4 Millimeters. Siren 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 | -16.7 °C | -5.6 °C | 21.34 mm |
| February | -14.9 °C | -2.6 °C | 23.62 mm |
| March | -7.8 °C | 4.3 °C | 39.12 mm |
| April | -0.8 °C | 12.1 °C | 71.12 mm |
| May | 6.3 °C | 19.7 °C | 98.3 mm |
| June | 11.9 °C | 24.6 °C | 112.27 mm |
| July | 14.3 °C | 27 °C | 105.66 mm |
| August | 13.1 °C | 25.9 °C | 105.41 mm |
| September | 8.6 °C | 21.4 °C | 86.61 mm |
| October | 2 °C | 13.6 °C | 82.8 mm |
| November | -4.9 °C | 4.5 °C | 42.93 mm |
| December | -12.1 °C | -2.7 °C | 31.24 mm |
| Annual | -0.1 °C | 11.9 °C | 820.42 mm |
| 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 : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |