condition mean min max 4 h after light 2.9 2.9 2.9 8 h after light 11.65 11.0 12.3 12 h after light 13.95 1.5 26.4 4 h after dark 4.55 4.5 4.6 8 h after dark 19.7 2.9 36.5 12 h after dark 7.65 2.3 13.0