The Sunny Side Up: An Interdisciplinary Overview of Sunlight’s Effects on our Health


  • Joseph Toth Honors College, University of North Texas



Sunlight, Insolation, Life Expectancy, Happiness, Vitamin D, Weather, Health


Do levels of daily sunlight exposure have a measurable effect on peoples’ health? I used to live in Michigan
where it is cloudy seemingly every day. This is drastically different from Texas, where the sun is almost always
shining. It is well known that an increase in sunlight exposure can drastically affect one’s mood; when looking at
cloudy areas versus areas full of sunshine, the difference in overall happiness and rates of depression can be
quite dramatic. Another factor to consider is that spending more time in direct sunlight can help with vitamin
D synthesis. Low vitamin D levels can lead to all sorts of health problems, demonstrating that having direct
sun exposure has the potential to be very influential in one’s health. To investigate whether sunlight can have a
measurable impact on peoples’ health and life expectancies, I collected data on average life expectancies and
reported happiness levels for all 50 U.S. States, as well as over 70 cities within the United States. These cities
were grouped together using K-means clustering to control for confounding variables, and then analyzed. This
allowed for an accurate representation of whether sunlight really does affect one’s health or not. Data came from
the United States Census Bureau, the CDC, and other reliable sources. This research highlights how certain
climate areas can affect our health, happiness, and overall life expectancy.