‘Happiness in the Sky’: New study reinforces the connection between sun exposure and mental well-being

A new peer-reviewed study published in Biodemography and Social Biology adds fresh scientific weight to what tanning professionals and sunshine lovers have long believed: a little sunlight can go a long way for your mood.

Titled “Happiness in the Sky: The Effect of Sunshine Exposure on Subjective Well-Being,” the study by Liu, Zhang, and Zhao examines how varying levels of sun exposure impact both life satisfaction and symptoms of depression. By combining precise daily sunshine data with a massive, nationally representative Chinese survey spanning nearly a decade, the researchers were able to offer one of the most comprehensive looks yet at how sunshine affects subjective well-being (SWB).

Sunlight and Satisfaction

The researchers found that individuals who were surveyed on sunnier days reported slightly higher life satisfaction than those interviewed on overcast days. Specifically, those experiencing more than eight hours of sunshine on the interview day were more likely to report being satisfied with life, while those with less than three hours of sunlight were measurably less satisfied.

Depression Scores Show Nonlinear Effect

The study also looked at depressive symptoms, using the well-established CES-D scale. Here, researchers found a nonlinear but meaningful relationship: individuals who experienced several days with 11+ hours of sunshine in the week leading up to their interview showed reduced symptoms of depression. One extra sunny day in that range correlated with a 0.061-point reduction in CES-D scores.

Who Benefits the Most?

While the overall effects were statistically significant, some groups seemed to benefit more:

Younger adults (ages 16–35) reported higher life satisfaction with increased sun exposure.
Older adults (56+) saw greater reductions in depressive symptoms.
Outdoor workers and families with young children were especially sensitive to sunshine fluctuations, likely due to more time spent outdoors.
Interestingly, people living in generally sunnier regions appeared more emotionally responsive to changes in daily sunlight—perhaps because they’re more used to good weather and notice its absence more acutely.

Citation:
Liu, S., Zhang, X., & Zhao, C. (2025). Happiness in the sky: The effect of sunshine exposure on subjective well-being. Biodemography and Social Biology. https://doi.org/10.1080/19485565.2025.2487977

SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can’t say in your tanning salon business.