Why is the sun so much brighter in winter?

Phoenix is known as the Valley of the Sun. And it’s no joke that we get a lot of sunshine year ‘round. About 300 days worth. Maybe you've noticed a subtle change in the quality of light as the seasons changed. Perhaps you've found yourself squinting more in the winter. Even sunglasses don't seem to help. Turns out it's not in your mind. The sun is truly brighter in the winter. So what is going on? Why is the sun so much brighter in the winter even though we have less hours of it? The Valley 101 team finds out. Learn more about your ad choices. Visit megaphone.fm/adchoices