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
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?
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
- 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 (available in November 2020) 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.
Our county maintenance crews are licensed and trained to handle the hazards of extreme weather conditions, out-of-control vehicles on slippery roads, abandoned vehicles, children playing near or in the road and steep terrain.
There are a very limited number of individuals in the region who are licensed and trained to drive snowplows on county roads under dangerous conditions. County and contracted crews who do this work are intimately familiar with county road conditions, hazards, and snow routes, and are experienced in driving graders or 10-yard trucks with plows, sanders, and attached ice treatment equipment.
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.