The barometric pressure is an issue for me and because I live a mile above sea level even the slightest change can be felt. I started using this
http://www.wunderground.com/history/...q_statename=NA Weather Underground to look at the pressure (you have to scroll way down to see it)at any given time of day to measure a correlation, and every single time there was a measureable difference in my symptoms and the drop in pressure. At the top you can chose to look at the history for any given day.
Granted the link I posted is for my area, but perhaps you can somehow use it for where you live. Not sure how I got to my particular location on that site because it was such a long tome ago that I made a permanent link on my PC. I would research it but I was just popping in for a minute. I have been feeling a little under the weather. No pun intended

Having a bug on top of the CRPS is always SO MUCH FUN!