Winter weather: Snow and ice
Call the 24/7 Road Helpline to report issues with snow and ice. If this is an emergency, call 9-1-1
Use the Winter Weather Response map to see plowed and sanded roads
Find answers to frequently-asked questions about snow & ice response
Get emergency preparedness resources
Español (Spanish), 中文 (Chinese), 한국의 (Korean), Русский (Russian), Soomaali (Somali), Українська (Ukrainian), Tiếng Việt (Vietnamese), Large type
Check your snow route
Will your route be clear this winter?
King County plows and treats 583 miles of designated snow and ice routes. If you do not live on a designated route, be prepared for the possibility you may need to stay home and avoid driving for up to several days during a major winter storm.
Primary routes for plowing and sanding in a countywide snow and ice event
Resources for emergency preparedness
Winter storm tip sheets from the Washington State Department of Health:
- English - large type (PDF 23KB)
- Español (Spanish) (PDF 34KB)
- 中文 (Chinese) (PDF 103KB)
- 한국의 (Korean) (PDF 158KB)
- Русский (Russian) (PDF 158KB)
- Soomaali (Somali) (PDF 37KB)
- Українська (Ukrainian) (PDF 116KB)
- Tiếng Việt (Vietnamese) (PDF 48KB)
Emergency preparedness information from other agencies:
Frequently-asked questions about snow and ice response
Phone: 206-477-8100; Relay: 711
Snow routes are categorized according to priority:
- Category 1 routes are plowed first, then category 2, category 3 and so on.
- Category 1 routes include main roadways (primary arterials, transit routes, lifeline routes) providing regional connections between communities.
- Category 2 routes are main roadways (primary arterials, main thoroughfares, and arterials leading to state highways) and minor arterials feeding densely populated areas.
- Category 3 routes are minor collectors that lead to and connect with Category 1 and 2 routes. These routes provide continuity between towns, cities, and large subdivisions. Category 4 routes are secondary commuter routes that connect Category 1, 2, and 3 routes along with other jurisdictions.
A countywide snow and ice event occurs when snow and ice response crews are needed in most or all areas of unincorporated King County at the same time.
Hazards in the roadway, such as fallen trees or downed power lines, extraordinary public safety needs or equipment breakdowns could delay snow-clearing work.
You can check our Winter Weather Response Map to see where our plows have recently cleared away snow.
We will work with first responders to clear roads that are outside of our designated snow routes during extraordinary public safety emergencies. However, in most cases, communities should not expect roads other than designated snow routes to be plowed and sanded in any type of storm.
King County crews from other departments such as the Department of Natural Resources and Parks are also trained to drive plows and help clear and sand roads within our designated snow route area when needed.
Please do not attempt to plow a county road.
Residents or contractors who plow a public road risk significant personal liability if someone is hurt or killed, or if property is damaged. Other jurisdictions such as Pierce and Snohomish counties also do not allow private residents or private contractors to plow public roads.
In 2021-22, King County plans to employ private snowplows and drivers who have a contract with King County to assist during very large, countywide winter storms. These seasonal private snowplow drivers would augment county crews and work under the direction of King County snow and ice removal supervisors.
Ice can form sooner on the decks of bridges and overpasses before it does on the roadway because air can circulate both above and below the surface of the elevated roadway, causing the pavement temperature to drop more rapidly. Ice can also form in shaded areas.
The calcium chloride (salt) adheres to the surface helping prevent ice from forming. Salt and water can cause rust on metal vehicles and equipment. Boost provides a chemical reaction that prevents rust from forming when the anti-icer solution comes into contact with vehicles and snow-removal gear.
Dry salt is most effective after the snow has accumulated about an inch and the temperature is 20 degrees Fahrenheit or higher. If the temperature is below 20 degrees, crews use a mixture of pre-wetted salt and sand to break up ice and increase traction. Pre-wetted salt and sand sticks to cold, icy surfaces better and jump-starts the ice melting process.
February 11-15, 2021 Snowstorm Recap
See a recap of King County Road Services' work during the February 11-15, 2021 snowstorm. Included are pictures and videos of our crews, in addition to data and information that shows how we supported residents in unincorporated King County by clearing roads during the storm event.