CIG Datasets

Global Climate Model Projections for the PNW


This dataset is a summary of the projected changes in average annual and seasonal temperature and precipitation from global climate model projections (GCMs) of 21st century climate change for the Pacific Northwest region. Data are derived from the two most recent Coupled Model Intercomparison Projects, Phase 3 (CMIP3¹, used in the 2007 IPCC report) and Phase 5 (CMIP5², used in the 2012 IPCC report). The term “coupled models” refers to the fact that modern GCMs model not just the atmosphere, but also its interactions with the land surface, ocean, and sea ice. There are numerous research groups around the world that have developed GCMs. Although there are many similarities among them, each group takes a different approach modeling the climate.

Read more about climate projections

Each of the CMIP projects developed a suite of greenhouse gas emissions scenarios to provide a basis for the GCMs to estimate future temperature changes. The emissions scenarios are comparable between CMIP3³ and CMIP54. For instance, the moderate A1B emissions scenario used in CMIP3 is very similar to the RCP 6.0 scenario used in CMIP5.

Read more about CMIP3 (projections used in the 2007 IPCC report)

Read more about CMIP5 (projections used in the 2012 IPCC report)

About the Dataset

In order to make it easier to explore the basic climate projections for our region, we have summarized the results from these models. GCM projections are summarized in two formats: (1) average change in temperature (°C) and precipitation (%), and (2) time-evolving projections, spanning from 1950 to 2100, averaged over each region. Results are summarized for four geographic regions:

  • Pacific Northwest (41.5-49.5N 124-111W)
  • West of the Cascades (41.5-49.5N 125-120.5W)
  • East of the Cascades (41.5-49.5N 120.5-111W)
  • Puget Sound (46.5-49.5N 123.5-120.5W)

Finally, we include projections for annual temperature and precipitation, as well as results for all four seasons (Dec-Feb, Mar-May, Jun-Aug, Sep-Nov).


Pacific Northwest regional average projections:


Puget Sound regional average projections:


Western Cascades regional average projections:


Eastern Cascades regional average projections:


Funding was provided by the Washington State Legislature.


Reports & References

1. Intergovernmental Panel on Climate Change. (2013) Working Group 1, Summary for Policymakers.

2. Taylor, K.E. et al. (2012) An overview of CMIP5 and the experiment design. Bulletin of the American Meteorological Society, 93(4): 485-498, doi:10.1175/BAMS’D’11’00094.1

3. Nakicenovic, N. et al. (2000) Special Report on Emissions Scenarios: A Special Report of Working Group III of the  Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, U.K., 599 pp. Available online at:

4. Van Vuuren, D.P. et al. (2011) The representative concentration pathways: An overview. Climatic Change. 109(1-2): 5-31.





Questions regarding this dataset can be directed to Guillaume Mauger (