Weird Knee Sounds

This morning I walked upstairs and as I walked off the last stair a loud, kind of gross, sound came from my left knee. It hurt momentarily, but when I took a couple of steps I realized it felt the best it's felt in a couple of weeks. Not that it's been hurting that much, but occasionally I get a twinge or notice it feels a little tender, rarely when I'm running. Anyway, on today's 6-mile run it felt fine. The temperature was about 90 degrees, and I walked progressively longer at each mile marker, including a longer walk up the big hill. I had a long work day and then had to chase down a cartridge for the upstairs shower at a plumbing supply company, which meant I got out later than usual. It didn't matter a whole lot temperature-wise, but I think I was the beneficiary of a little more shade than if I'd run earlier.