There is a peculiarity of the local climate to which I've never quite become accustomed. This time of year, the air flows down the piedmont of the Sierra all night long, in a steady breeze that makes the pines whisper. The evenings are usually very cool, but, as the night passes, the air gradually grows warmer until, in the hours before dawn, it often will be rather balmy. I think that the high pressure system over the inland deserts must gradually shift seaward, compressing the air as it goes. I still find it strange to go outdoors about this time of day and find it warmer than it was before midnight.