It's more about the oceanic climate. According to the map in the article, continental areas at similar latitudes see more thunderstorms than the UK. I guess tha

It's more about the oceanic climate. According to the map in the article, continental areas at similar latitudes see more thunderstorms than the UK. I guess that's mostly because temperate thunderstorms often happen near the front between cold and warm air masses, and continental climates give you more opportunities for that.