4th of July "Firecracker" 100km Ride

My 4th of July ride today was about as enjoyable as any ride I've done (the oppressive heat toward the end of the ride being the only downer). It's a popular metric century held here every year with almost 1000 participants of all skill levels. I stayed with a group more or less for the first 42 miles--although the pace wasn't very steady at times--then had to bridge a 2 minute gap when I missed a stoplight after stopping to refill my water bottles. When I finally caught the group I had been pacelining with they had slowed considerably so I ended up finishing the ride on my own in no-man's-land between two groups. Average speed: 22.5 mph.

What's interesting to me is a comparison of today's results with my ride two days earlier. I rode the same course on Sunday to make sure I wouldn't miss a turn but as opposed to today's early morning start, I didn't leave until about noon. It was a scorcher out there and my heart rate was noticeably affected. My average heart rate for both rides was about 155 but my average wattage on Sunday was only about 180 as compared to today's average of 210. That's quite a difference!