Humidity, temperature & barometric pressure affects joint pain, migraines and muscle pain (for example in fibromyalgia).
What can you do about it?
Well, apart from moving to the Sahara desert, or a similarly dry and exciting place, you can buy a good hygrometer and barometer, and notice how your pain scale is affected by the changes in weather.
Once you have some basic understanding of how your aches and pains respond to changes in the weather, you may be able to implement different strategies at an earlier time. Instead of being hit with the surprise super-migraine every time the pressure drops dramatically, and feeling like a giant failure for not being able to cope with your responsibilities that day, cut yourself some slack. Grant yourself a soft "stay-at-home-and-be-kind-to-yourself-day" - maybe using some of the other tips in this blog - when you see the telltale signs of a painful weather alignment coming on.
That way, the pain may still come, but you can limit how much it wears on you, and you won't necessarily feel so bad about it.