I broke my ankle a few years ago, and ever since then it’s been sensitive to the weather. We’re now in day five of a very cool (20 degrees below normal), very rainy period – and my ankle has definitely been grumbling about it. I can also use my ankle to predict rain (though not with perfect accuracy).
What causes this, and what is it reacting to – humidity? barometric pressure?
Low barometric pressure, as I recall reading.
Apparently there is a field of study, human biometeorology, exploring the relationship between weather and health.
<<Although many believe in the connection between weather and health, most medical studies have come up with equivocal support at best. … The suspect most often singled out by arthritis sufferers and researchers is a drop in barometric pressure, which is the pressure exerted by the air around us. A drop in barometric pressure often precedes a storm, and the theory goes that a decrease in the air pressure can cause the tissues around the joints to swell, causing arthritic pain. … However, it’s important to note that this process is entirely theoretical because the swelling – if it really is taking place – is happening on such a small scale that it cannot be detected by any scientific means. Since there is nothing that can be charted medically, study of the subject is reliant on subjective accounts of arthritic pain, which are hard to compare from one person to another. >>
It does have a barometric pressure/humidity tie. My reassembled right leg makes me aware of damp and foggy conditions. The physicial therapist at Healthsouth claimed it was quite common.
If it’s so – and apparently that’s somewhat in doubt – why at the site of an old break? The bone has pretty much knit back together at this point, right? So why would the previously broken spot be more sensitive to air pressure and/or humidity than an intact spot?
I have a 1-inch scar on the arch of my left foot – childhood accident – and ~48 hours before a drastic weather change it starts to itch and drive me crazy. I was sharing this with my aged mother (nearly 80) a few years ago and she remarked that she has a scar on her back – from old back surgery – that does the same thing.
weird family 
Yeah, I don’t think it’s just bones. I have a nasty scar on my right pinky from a childhood accident, and in cold weather that scar, specifically, is the first thing to hurt. As I’ve gotten older and the scar has become less pronounced and dramatic, the pain has lessened too, but it’s never gone entirely away.
For the record, I did also break the tip off the bone in that accident, the doctors told me, but it was just the tip and they didn’t do anything to put it back together. So I’m pretty sure it’s not the broken and healed break that’s hurting. Plus it’s very clearly the scar, not deeper.
Changes in weather are considered one of the triggers for migraine headaches. There have been times when that would be plausible for me.
Also, as a teacher, I’m convinced that kids are affected by rapidly changing barometric pressure. They get squirrellier than hell. I want a double blind test of my hypothesis.
Is it shaped like a lightning bolt?
I broke my leg and it hurts when weather changes as well.
My junior high science teacher kept a barometer in her lab. She said that whenever the principal had an unusual number of disciplinary problems to deal with, he would come by and ask her if the barometer was dropping.
If the “explanation” is a drop in air pressure, why does it not happen to people when they are on planes (pressurized to well below atmospheric)?
Here is a study examining the claim (PNAS is quite a reputable journal, btw).
I used to get sinus/migraine type headaches when a bout of cloudy/rainy weather shifted back to clear and sunny. I’d usually wake up with one on the morning of the change.
I don’t seem to get them very often here where the weather is consistently sunny, at least part of the day (San Diego.)
Big sudden changes like driving in the mountains, flying, swimming, rain in Florida could just be overpowering the very never endings that react to the small and slow changes of a weather system. Our Mimosa tree closes up at night and before a rain. good short time predictor of actual rain in our yard. But… It does not react to being sprayed with a hose…
I have a stainless steel upper arm bone and what feels like bone pain happens during weather changes, Well, I know the steel has no nerves but the surrounding tissue sure does. The phenomenon certainly hurts me for real so…
Me too and recently I was pleasantly surprised to find my employers accepted that reason without question. I guess people have finally got away from the idea that all migraines are caused by chocolate! 
For some reason I sometimes find that if I have a migraine starting then simply going outside can somehow ‘blow away’ a lot of the pain. I’m not sure why since presumably there is litte difference in barometric pressure indoors and outdoors.
I have an annoying weather sensitivity in an oldknee injury. It apparently aches when the barometric pressure goes up. So I’ll get out of bed in the morning, “Ouch! Hey, did it rain last night?”
I wish I had an injury that would give me weather data I couldn’t get by looking out the window. 
Yep. I’m another one who gets migraines when the barometer is falling. I can tell with near 100% accuracy when it’s going to rain or snow. I get pain across my forehead and behind my eyes. Once the precipitation starts, the pain stops.