A lot of folks wait until bed time to do magnesium flake/epsom salt baths, but I sometimes start my day with one, too.
Along with the cold, keep an eye on the barometric pressure. There was a big study done that said that fibro wasn't affected by it ....except for the 15% of people who were. :rolleyes:
For me if it changes a lot, or really quickly, it can spike a flare so I keep a close eye on the weather.