| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F Zone 7b: 5°F to 10°F Zone 7a: 0°F to 5°F | |
| 2012 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 6b: -5°F to 0°F Zone 7b: 5°F to 10°F Zone 7a: 0°F to 5°F Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 1b: -15F to -10F | |
| Average First Frost Date: | Sep. 21 - Sep. 30 | |
| Average Last Frost Date: | May 21 - May 31 | |
| Koppen-Geiger Climate Zone: | Dsb - Humid Continental Climate - Dry Cool Summer | |
| Ecoregion: | 11i - Continental Zone Foothills | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 97870 - Richland, OR | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 18 | 22 | 28 | 33 | 40 | 47 | 52 | 51 | 42 | 33 | 26 | 19 | 34 |
| Avg Max Temp (°F) | 36 | 43 | 53 | 62 | 71 | 79 | 89 | 89 | 79 | 65 | 46 | 37 | 63 |
| Avg Precip (In.) | 1.34 | .99 | .94 | .99 | 1.29 | 1.02 | .67 | .7 | .47 | .62 | 1.39 | 1.39 | 11.79 |