| 2023 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 8a: 10°F to 15°F | |
| 2012 Hardiness Zone: | Zone 8a: 10°F to 15°F | |
| 1990 Hardiness Zone: | Zone 8a: 10F to 15F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| Average Last Frost Date: | May 1 - May 10 | |
| Koppen-Geiger Climate Zone: | Csb - Warm-Summer Mediterranean Climate | |
| Ecoregion: | 2i - Cowlitz/Newaukum Prairie Floodplains | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 98570 - Onalaska, WA | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 32 | 34 | 35 | 38 | 43 | 47 | 51 | 51 | 46 | 41 | 37 | 33 | 41 |
| Avg Max Temp (°F) | 45 | 50 | 54 | 60 | 66 | 71 | 77 | 78 | 73 | 61 | 50 | 45 | 61 |
| Avg Precip (In.) | 7.09 | 6.04 | 5.65 | 4.2 | 2.97 | 2.48 | .99 | 1.52 | 2.38 | 4.54 | 7.49 | 8.54 | 53.88 |