As December ushers in snowy days and fewer daylight hours, I find I am grateful for every minute of sunshine I can get. Even ten minutes outside in the sun can renew my energy for the remainder of the day. I grew up in the Midwest where winters often consist of many grey snowy days and very few opportunities to enjoy the sun. As a result, I find winters in Colorado much brighter and happier.
As the days got shorter and shorter before the winter solstice, I found myself wondering which areas in the U.S. receive the most sunshine each year. I found some historical sunshine and cloud data online consisting of the total hours of sunshine each month at over 250 monitoring locations in the U.S collected between 1908 and 1992. I used this data to calculate the average number of sunny days per year at each location and then plotted the results as a gradient map in MapViewer 8 GIS software.