I think the drop in temperature is majorly because of the trees and the fact that you're heading into a region with more trees and more water areas. Trees can keep the cold in, I think.
Great place, great pictures. I think this might be the first time you're visiting here?
Yes, it was my first time going down to this canyon stream. Not a whole lot of sunlight available at the bottom either, which made it cooler.
Must've been amazing, and that low light didn't impact the quality of the images
That is where lightroom comes in handy.