Temperatures do not often switch between great extremes, with warm summers and mild winters.
The British Isles undergo very small temperature variations. This is due to its proximity to the Atlantic, which acts as a temperature buffer, warming the Isles in winter and cooling them in summer.
Over here, in the US, the places with the lowest temperature variations are also islands, like Hawaii. Extreme temperature swings happen in places like the Dakotas, far away from the ocean.
You’ve been cursed with fairly comfortable temperatures. :-)