Centralia, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.6 °C (low) to 16.6 °C (high). Annual precipitation averages 1150.6 Millimeters. Centralia is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.6 °C | 8.3 °C | 164.85 mm |
| February | 1.3 °C | 10.2 °C | 116.59 mm |
| March | 2.4 °C | 12.7 °C | 127 mm |
| April | 3.9 °C | 15.6 °C | 87.63 mm |
| May | 6.9 °C | 19.4 °C | 55.63 mm |
| June | 9.3 °C | 22 °C | 41.66 mm |
| July | 11.2 °C | 25.7 °C | 13.21 mm |
| August | 11.2 °C | 26.3 °C | 19.56 mm |
| September | 8.9 °C | 23.2 °C | 40.89 mm |
| October | 5.8 °C | 16.7 °C | 106.93 mm |
| November | 3.1 °C | 11 °C | 191.77 mm |
| December | 1.3 °C | 7.7 °C | 184.91 mm |
| Annual | 5.6 °C | 16.6 °C | 1150.63 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 40-50 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 | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |