Most of my relatives live in the Vancouver/Portland area. Generally speaking, in the summer it is about 10 degrees hotter than the Seattle/Tacoma area and in the winter Vanc./Port. area is about 10 degrees cooler than Sea./Tac. area. I believe this has a lot to do with the Columbia River.
Also, in the winter Vanc./Port. will get "silver thaws". That is when it has snowed, the temperature rises to start everything melting and then suddenly the temperature drops back down to freezing. Everything drips icicles and the branches on trees will break, also power lines sometimes come down because of the weight or a tree limb takes them down.
It is beautiful to see but can wreck havoc--no power and roads are like ice rinks.
There does not seem to be as many "silver thaws" as in years past but they are more often in the Vanc./Port. area than Sea./Tac.; once again, because of the wind that comes whistling up the Columbia River (or at least that is what my dad always said

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