The stream temperature change maps depict projected future stream temperatures in Snohomish County from the U.S. Forest Service’s regional NorWeST stream temperature project. The maps were developed at a 1-kilometer resolution using spatial statistical stream network models. Stream temperature data used to fit the temperature model that created the scenario maps were screened using a consistent set of criteria to ensure the use of accurate temperature measurements. Application of these techniques in previous research has yielded accurate and unbiased stream temperature models and predictions (R2 ~ 0.90; RMSE < 1.0 ˚C; for more details, go here: http://www.fs.fed.us/rm/boise/AWAE/projects/stream_temp/spatial_temp_model.shtml). Projected temperature changes were derived from a spatially explicit delta method (Hamlet et al. 2010) using the A1B scenario for the 2040s (2030-2059) and 2080s (2070-2099).

Source: United States Department of Agriculture – U.S. Forest Service: Regional Database and Modeled Stream Temperatures (USDA 2014)

Salmonid Temperature Thresholds
<58.1°F (<14.5°C)	Optimal range for salmon spawning, rearing, and migrating
59.9 – 67.1°F (15.5 – 19.5°C)	Range for increased disease risk in adult salmon
68.9 – 70.7°F (20.5 – 21.5°C)	Threshold for adult salmon mortality
>70.7°F (21.5°C)	Threshold for juvenile salmon mortality

 

Source: Climate Change Effects and Adaptation Approaches in Freshwater Aquatic and Riparian Ecosystems in the North Pacific Landscape Conservation Cooperative Region, 2011, page 136 (http://www.nwf.org/~/media/PDFs/Global-Warming/2014/Freshwater-Report/NPLCC_Freshwater_Climate-Effects_Final.pdf)