Scientists have confirmed something most people have long suspected … that sunshine is one of the very best ways to ward off the winter blues.

A woman in a hammock on the beach.
A woman in a hammock on the beach.

However, a unique new study has revealed that sunshine may not actually be the most important factor but more so the numbers of hours of daylight between sunrise and sunset, irrespective of the actual weather. That means next time you book an autumn or winter holiday to escape long dark days, it may well be worth flying somewhere where the days are much much longer, and not just somewhere that is warmer. The research by Brigham Young University cross-referenced weather and daylight data against visits to psychologists in their local area.

Interestingly, things like rainy days, irritatingly warm weather, even heavy air pollution were not generally factors affecting people’s mood. Instead, it mostly seemed to hinge on the number of hours between sunrise and sunset, irrespective of what the weather was actually like during daylight. The findings applied to the population at large as well, not just those who had officially been diagnosed with seasonal affective disorder (or SAD).

Family day out at the beach.
Family day out at the beach.

Mark Beecher, a clinical professor involved in the research, said: “On a rainy day, or a more polluted day, people assume that they’d have more distress but we didn’t see that. “We looked at solar irradiance, or the amount of sunlight that actually hits the ground. We tried to take into account cloudy days, rainy days, pollution … but they washed out. The one thing that was really significant was the amount of time between sunrise and sunset.” The study began after a conversation between Prof Beecher and a colleague, physics professor Lawrence Rees when they were discussing the possibility that rainy days might make a psychologist much busier.

So they decided they would take a closer look at very precise weather data in their area and also emotional health data for people living there. They looked at wind chill, rainfall, wind speed, temperature, but found the factor that overrode all others was hours of daylight.

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