Sisco Heights, Washington has a Warm-Summer Mediterranean Climate climate (Köppen classification: Csb). Average annual temperatures range from 43.5 °F (low) to 59.2 °F (high). Annual precipitation averages 51.4 Inches. Sisco Heights is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.2 °F | 45.5 °F | 6.76 in. |
| February | 35.2 °F | 48.0 °F | 4.81 in. |
| March | 37.7 °F | 52.0 °F | 5.5 in. |
| April | 41.1 °F | 57.8 °F | 4.25 in. |
| May | 46.3 °F | 64.4 °F | 3.09 in. |
| June | 50.1 °F | 68.1 °F | 3.01 in. |
| July | 53.7 °F | 74.7 °F | 1.2 in. |
| August | 54.3 °F | 75.6 °F | 1.17 in. |
| September | 50.6 °F | 70.3 °F | 2.81 in. |
| October | 44.5 °F | 59.2 °F | 5.4 in. |
| November | 38.4 °F | 50.0 °F | 7.09 in. |
| December | 35.0 °F | 44.9 °F | 6.29 in. |
| Annual | 43.5 °F | 59.2 °F | 51.38 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Csb - Warm-Summer Mediterranean Climate |