| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F |
| 2012 Hardiness Zone: | Zone 5a: -20°F to -15°F |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F |
| Average First Frost Date: | Oct. 1 - Oct. 10 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year |
| Ecoregion: | 53c - Southeastern Wisconsin Savannah and Till Plain |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 54923 - Berlin, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 6 | 11 | 22 | 34 | 46 | 55 | 60 | 58 | 49 | 38 | 26 | 13 | 35 |
| Avg Max Temp (°F) | 24 | 30 | 41 | 55 | 69 | 78 | 82 | 79 | 71 | 59 | 43 | 29 | 55 |
| Avg Precip (In.) | 1.2 | 1.09 | 2.09 | 2.99 | 3.24 | 3.85 | 3.97 | 4.12 | 3.5 | 2.31 | 2.26 | 1.4 | 32.02 |