The west coast of Scotland is so warmed by the Gulf stream that palm trees grow on the Islands. This is about 55 degrees latitude, about the same latitude as the lower area of the Hudson Bay in Canada.
Those palm trees didn’t get there by themselves, of course. Somebody introduced them.
There are palm trees in Kensington Garden in London, too. I don’t think that type of palm tree requires a very temperate climate. They trees have been there for a long time, well before global warming.