| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F |
| Average First Frost Date: | Oct. 11 - Oct. 20 |
| Average Last Frost Date: | May 11 - May 20 |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers |
| Ecoregion: | 53d - Lake Michigan Lacustrine Clay Plain |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 53074 - Port Washington, WI | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 13 | 17 | 27 | 37 | 46 | 56 | 63 | 62 | 54 | 43 | 31 | 19 | 39 |
| Avg Max Temp (°F) | 27 | 32 | 41 | 50 | 62 | 72 | 78 | 77 | 70 | 59 | 44 | 33 | 54 |
| Avg Precip (In.) | 1.47 | 1.18 | 1.93 | 3.16 | 2.93 | 3.58 | 3.77 | 4.18 | 3.47 | 2.32 | 2.27 | 1.83 | 32.09 |