condition mean min max 4 h after light 745.5 745.5 745.5 8 h after light 630.05 513.7 746.4 12 h after light 594.8 498.8 690.8 4 h after dark 639.6 570.1 709.1 8 h after dark 642.5 572.0 713.0 12 h after dark 560.7 480.8 640.6