Sounds like when I have a arthritis flare. I call it musical joints, the pain moves from one joint to another with no rhyme or reason. I will go to bed with my knees hurting and wake up with the pain in a completely different place. How hope I'm wrong I don't wish arthritis on anyone.

Mine just started a few hours ago, right knee for now. Temperature dropping steadily from 60˚ a few hours ago to 18˚ by Thursday morning. An interesting drop, in that it will steadily decline straight on through, hour by hour.

My guess is that I have chunks floating in the knee, and rapid changes in pressure screw around with these floaters.

Pop had them removed from his knee when he was a few years older than I am now.