IT’S not the heat, it’s the humidity. Across great stretches of the US, the
old cliché is putting in its annual appearance as sweltering weather sets
in.
Having languished through 15 uncomfortable summers around Washington DC and
in the upper Midwest, I can testify that like all the best clichés, this
one’s true. And for a sound reason. When the air’s moist, evaporative
cooling—sweating to you and me—doesn’t work as well. You feel
hotter.
But American weather forecasters don’t like qualitative statements. If they
can find a way of putting a number on something, they will. And…
