condition mean min max 4 h after light 17.2 17.2 17.2 8 h after light 15.05 10.4 19.7 12 h after light 19.5 18.4 20.6 4 h after dark 47.8 44.9 50.7 8 h after dark 26.7 22.4 31.0 12 h after dark 17.0 2.6 31.4