Climate Projections

The Intergovernmental Panel on Climate Change (IPCC) estimates that human activity has already caused a 1°C (1.8°F) of warming, impacting people, economies, and ecosystems around the world. The Paris Agreement is an international effort aimed at keeping global temperature change “well below” 2°C (3.6°F) to limit the worst impacts of climate change. Even with these efforts to limit climate change, impacts are already being felt in Washington, and are anticipated become more severe and wider spread as time goes on.

To be able to plan for and adapt to these changes, we need to understand how the climate will change in Washington State, and what the impacts will be. Climate change projections provide this information through mathematical modeling of the anticipated changes.

As the climate changes, there will continue to be natural variability in the weather. Weather can have hourly, daily, and even seasonal variability. Climate change is the average change in weather over time. Climate projections model the shift in the expected climate over a range of time.

View the Projections

The climate projection data consists of projected changes in temperature and precipitation between 2036 and 2065, the thirty-year time span centered around 2050. Temperature and precipitation climate projections were selected because they are relevant to public health, can be displayed at a census tract level, and have impacts across the state. Due to limited data availability, not all potential climate risks are included. For example, sea level rise, inland flooding, and wildfire risk are not included.

The climate projection measures are:

Change in Precipitation

Days Over 99th Percentile Temp

Change in Cooling Degree Days

Change in Heating Degree Days


Projections information can also be found in the “Climate Projections ~2050” overlay on the Environmental Health Disparities (EHD) map. Overlaying climate projections on the EHD map shows the uneven impacts of climate change in relation to other environmental health factors.

Open the Information by Location tool and select Environmental Health Disparities from the Topic menu. Navigate to the Map Features menu and select the “Climate Projections ~2050” map. Select a census tract on the map to see the climate projection data and ranking for that census tract.


This work is the result of a collaborative effort among: University of Washington's Department of Environmental and Occupational Health Sciences, University of Washington's Climate Impacts Group, University of Washington's Center for Health and the Global Environment, Front and Centered, and the Washington State Department of Health.

Additional Resources

DOH Clean Energy Transformation Act Cumulative Impact Analysis

University of Washington's Climate Impacts Group

University of Washington's Center for Health and the Global Environment

Paris Agreement

Intergovernmental Panel on Climate Change