By then the heat of the day is often at its highest and...well, kind of like when you take a warm bath. Heat often brings about low hangers, you know? We're also out of our air-conditioned offices by then and out into the heat of late afternoon.
And, of course, gravity has had its chance to pull for a longer period by then, too. Much like we're taller in the morning before we're brought down by the earth's pull.
Or, maybe not.