Here's a pretty good article on arthritis and how it relates to weather. Research shows changes in barometric pressure affect the pressure in our joints. It doesn't "cause" arthritis, but for those of us who have it, it sure does make the symptoms worse!
The Centers for Disease Control believes approximately 50 Million people suffer from arthritis on some level with women developing symptoms at a higher rate than men.
The good news is, there are ways to reduce the impact it has on our day and Massage Therapy is one of them! While direct massage to joints is NOT a recommended approach during a flare-up, light, Swedish Techniques applied to the surrounding muscle tissue can go a long way toward getting those muscles into a more relaxed state. With more relaxed muscle tissue, you have a bit less outside pressure affecting the joint.
Massage Therapy isn't going to cure arthritis (nothing else does, either) but there's enough anecdotal evidence out there to suggest it's a very valid way to help manage the symptoms.
Quick Tip: If you have been diagnosed with Osteoarthritis (as opposed to Rheumatoid Arthritis) get off the heat during flare-ups and use cold packs instead. Your joint is already inflamed and adding heat (expansion) is going to add to the inflammation.