My hikes typically start in a valley in the morning, where cold air has settled all night, and head uphill. If the valley’s fogged in I’ll hike from cool, moist valley air into sun-warmed hilltop air. I think the experts call these things thermal layers — and the implication is there’s a place where one layer ends and the next one starts.
Typically I’ll go from one layer to the other and not notice the cutoff, but yesterday something amazing happened: I was on a flat stretch of trail between two hilly sections and I noticed something odd: my head could feel hot air while my body could feel cold air. Always something new on the trail; this time it’s me hiking through two thermal layers at the same time.
As long as I’m on the subject of temperatures … last weekend I was about three miles into my hike at Henry Coe State Park when I crossed a stream after descending an excessively steep gravel road. The road’s incline was nasty enough that I had worked up a pretty good sweat. As soon as I stepped out of the water it felt like my body’s temperature-regulation system had just been rebooted. Where before I was dry and bordering on uncomfortably warm, now I had squishy wet feet but the rest of me seemed like all its default settings had been restored. I felt comfortable and normal, which came as a distinct surprise, considering I was carrying 20 pounds of gear and had just hiked three miles. I’ve always liked stomping through puddles; now I’ve got a permanent excuse for indulging the urge.
One last temperature note: it appears we’ve seen the last of the cool, damp, rainy weather around the Bay Area. won’t be long till we’re all complaining about how hot it is on the hills.