Lacey, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 5.6 °C (low) to 16 °C (high). Annual precipitation averages 1392.2 Millimeters. Lacey is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.4 °C | 8.2 °C | 202.69 mm |
| February | 1.2 °C | 9.8 °C | 129.79 mm |
| March | 2.3 °C | 12.2 °C | 151.38 mm |
| April | 3.9 °C | 14.9 °C | 104.65 mm |
| May | 6.9 °C | 18.8 °C | 65.02 mm |
| June | 9.4 °C | 21.3 °C | 46.48 mm |
| July | 11.3 °C | 25.1 °C | 17.78 mm |
| August | 11.3 °C | 25.4 °C | 32.26 mm |
| September | 9 °C | 22.3 °C | 51.56 mm |
| October | 5.8 °C | 15.9 °C | 132.08 mm |
| November | 2.9 °C | 10.7 °C | 245.36 mm |
| December | 1.2 °C | 7.6 °C | 213.11 mm |
| Annual | 5.6 °C | 16 °C | 1392.16 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |