condition mean min max 4 h after light 21.6 21.6 21.6 8 h after light 11.7 11.5 11.9 12 h after light 11.9 8.8 15.0 4 h after dark 8.0 3.0 13.0 8 h after dark 14.3 13.0 15.6 12 h after dark 9.3 8.1 10.5