Yeah thank you to the gulf stream. Too bad that global warming will make it disappear ¯\(ツ)/¯

Also wind patterns. At the midlatitudes westerlies dominate. So the east coast has a continental climate (receives cold air in the winters, hot air in the summers) while the west coast does not (the oceans make the summers and winters mild)

You'll see that the west coast cities on the same latitudes of their European counterparts have a very similar climate (as opposed to east coast cities, which have a very different climate than their latitude-counterpart).

So do the Great Lakes. Although, currently the lakes are generating their own weather.