| 2023 Hardiness Zone: | Zone 5a: -20°F to -15°F Zone 4b: -25°F to -20°F | |
| 2012 Hardiness Zone: | Zone 4b: -25°F to -20°F | |
| 1990 Hardiness Zone: | Zone 4b: -25F to -20F | |
| Average First Frost Date: | Oct. 1 - Oct. 10 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 50t - North Shore Highlands | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 55812 - Duluth, MN | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 0 | 7 | 18 | 30 | 40 | 49 | 56 | 56 | 47 | 36 | 23 | 8 | 31 |
| Avg Max Temp (°F) | 19 | 25 | 35 | 47 | 59 | 69 | 75 | 74 | 65 | 53 | 37 | 24 | 48 |
| Avg Precip (In.) | .97 | .56 | 1.42 | 1.63 | 2.42 | 3.84 | 3.87 | 3.81 | 3.82 | 2.01 | 1.52 | .85 | 26.73 |