The second year I lived here, in Colorado, was the first time I rode my mountain bike above treeline. It was on the Colorado Trail, at the top of Georgia Pass.
I was still new to the area, and not quite hip to the terrain. I understood that the temperature was cooler, at higher elevations. I understood that trees didn't grow above a certain elevation due to the climatic conditions.
Still, I was a Son of The South, and I thought of July as being the month of heat and mosquitoes. So, when we got to the top of the pass, in the third week of July, and it snowed on us...Well, I was a bit gobsmacked.
Maybe not Christmas in July, but definitely Winter in July.