Lebanon, Oregon has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 6.1 °C (low) to 17.7 °C (high). Annual precipitation averages 1050.3 Millimeters. Lebanon is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.8 °C | 8.7 °C | 148.34 mm |
| February | 1.9 °C | 10.8 °C | 108.2 mm |
| March | 3.2 °C | 13.3 °C | 127.76 mm |
| April | 4.8 °C | 16.1 °C | 94.23 mm |
| May | 7.4 °C | 20 °C | 64.26 mm |
| June | 9.8 °C | 23.1 °C | 41.4 mm |
| July | 11.8 °C | 28.4 °C | 9.65 mm |
| August | 11.6 °C | 28.8 °C | 9.65 mm |
| September | 9.4 °C | 25.3 °C | 41.15 mm |
| October | 6.3 °C | 18.2 °C | 85.34 mm |
| November | 3.7 °C | 11.7 °C | 150.37 mm |
| December | 1.6 °C | 8.1 °C | 169.93 mm |
| Annual | 6.1 °C | 17.7 °C | 1050.28 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |