Carson, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 42.1 °F (low) to 61.7 °F (high). Annual precipitation averages 63.3 Inches. Carson 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 | 32.5 °F | 42.4 °F | 8.82 in. |
| February | 33.2 °F | 47.3 °F | 6.97 in. |
| March | 35.6 °F | 53.5 °F | 6.95 in. |
| April | 39.5 °F | 60.1 °F | 5.11 in. |
| May | 44.9 °F | 68.2 °F | 3.35 in. |
| June | 49.8 °F | 73.6 °F | 1.78 in. |
| July | 54.3 °F | 81.9 °F | 0.59 in. |
| August | 54.2 °F | 82.4 °F | 0.49 in. |
| September | 48.8 °F | 76.1 °F | 2.06 in. |
| October | 42.7 °F | 62.7 °F | 6.42 in. |
| November | 37.0 °F | 49.8 °F | 9.64 in. |
| December | 32.6 °F | 42.1 °F | 11.13 in. |
| Annual | 42.1 °F | 61.7 °F | 63.31 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |