Long-term trends in weather are collectively called Climate, the Vital Sign that drives them all. Plants and animals take their cues from the changing seasons regulating the pulse of the ecosystem. Because of the central impact of climate to all life, humans are increasingly concerned about climate trends and specifically, whether and to what degree we are changing those patterns.

Climate is monitored at Ebey's Landing, Fort Vancouver, Lewis and Clark, Mount Rainier, North Cascades, Olympic, and San Juan Island.