In my case it’s clear blue skies and anything like stillness or being relaxed.
Edit: for some context the footage of 9/11, the people falling off the plane in Afghanistan, the explosion in Beirut, and many others had that same ominous clear blue sky in the background.
My surgically repaired ankle starts to hurt when the barometric pressure drops which is a harbinger of thunderstorms here. The more severe the pain the more severe the weather.
It has done this since I was in my late 20s, so yeah I sound like an old man, but it was true even when I was young. Took me a few years to work out the connection between the ankle pain and the weather.
It is hurting a decent amount today and storms are predicted for the whole weekend here in north Texas.