For this week's Viz of the Week, we pulled data from Walk Score, Census, and the Center for Disease Control (CDC) to find the best cities for training for a marathon. We evaluated the 25 most populous cities in the country. One factor was the amount of sunlight in each county, which created a beautiful display of the variance of sunlight across the continental United States.

View the other tabs for our best cities for runners: out of 25 points, we gave Walk Score and park density 10 points each, temperature 4 points, and sunlight 1.