I've been wondering about it for the longest time, mostly because I don't really pay much attention to lore that's not directly in the MSQ, but how come some fairly common weather patterns are only seen in certain areas? Thunder and thunderstorms are a perfect example, they only happen in South Shroud. Why? Is something there? Ramuh originates from East Shroud, I never see it storm there. It monsoons all the time in East Thanalan, still no lightning though. Heat waves are another one, all of Thanalan is desert plains, but you only see that in Southern Thanalan. And I believe you only see windy weather in West La Noscea, despite high winds being possible anywhere from a meteorological standpoint. Correct me if I'm wrong on that though.

3 years of playing and I never really cared enough to ask until it bugged me enough sitting in Quarrymill watching a thunderstorm, waiting for a Palace queue.