| 2023 Hardiness Zone: | Zone 8b: 15°F to 20°F | |
| 2012 Hardiness Zone: | Zone 8b: 15°F to 20°F | |
| 1990 Hardiness Zone: | Zone 8a: 10F to 15F | |
| Average First Frost Date: | October 11 - 20 | |
| Average Last Frost Date: | April 21 - 30 | |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate | |
| Ecoregion: | 2b - Eastern Puget Riverine Lowlands | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 98390 - Sumner, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 33 | 34 | 36 | 39 | 44 | 49 | 52 | 52 | 48 | 42 | 37 | 33 | 42 |
| Avg Max Temp (°F) | 46 | 50 | 54 | 59 | 65 | 70 | 76 | 77 | 71 | 61 | 51 | 45 | 60 |
| Avg Precip (In.) | 5.52 | 4.63 | 4.22 | 3.06 | 2.16 | 1.79 | .89 | 1.2 | 1.81 | 3.38 | 6.26 | 5.93 | 40.83 |