Hours of Sunlight for Counties at High Risk for SAD

The data in this figure represents the average percent of daylight hours over a 6-year period grouped by season in areas at high risk for seasonal affective disorder. In most U.S. states, time is set back an hour between the fall and winter season (standard daylight time), and then moved an hour forward between spring and fall. The Sunshine Protection Act would eliminate the standard time, which would effectively extend the number of civil hours that coincide with the daylight hours. Solar and climate data was obtained from NSRDB: National Solar Radiation Database and MeteoStat. The percentages in the tooltip is the average winter percentage for that variable in that county.