| 2023 Hardiness Zone: | Zone 5b: -15°F to -10°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: | 53d - Lake Michigan Lacustrine Clay Plain |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 54303 - Green Bay, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 7 | 12 | 22 | 34 | 45 | 54 | 59 | 57 | 48 | 37 | 26 | 14 | 35 |
| Avg Max Temp (°F) | 24 | 29 | 39 | 54 | 67 | 76 | 80 | 78 | 70 | 57 | 42 | 29 | 54 |
| Avg Precip (In.) | 1.36 | 1.07 | 2.07 | 2.61 | 2.83 | 3.44 | 3.43 | 3.74 | 3.17 | 2.24 | 2.32 | 1.5 | 29.79 |