New Berlin, Illinois has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.3 °C (low) to 17.3 °C (high). Annual precipitation averages 988.1 Millimeters. New Berlin is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.2 °C | 1.7 °C | 52.58 mm |
| February | -5.3 °C | 4.6 °C | 47.75 mm |
| March | -0.2 °C | 10.9 °C | 69.85 mm |
| April | 5.7 °C | 18.1 °C | 104.39 mm |
| May | 12.1 °C | 23.5 °C | 118.62 mm |
| June | 17.2 °C | 28.2 °C | 117.6 mm |
| July | 18.9 °C | 29.8 °C | 97.03 mm |
| August | 17.7 °C | 29.3 °C | 85.34 mm |
| September | 13.1 °C | 26.4 °C | 84.58 mm |
| October | 6.7 °C | 19.4 °C | 79.25 mm |
| November | 0.7 °C | 11.2 °C | 76.2 mm |
| December | -4.2 °C | 4.6 °C | 54.86 mm |
| Annual | 6.3 °C | 17.3 °C | 988.05 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |