The Scientific Reasons We're Happier In The Summer

There's something about waking up to sunshine, birds chirping, and warm air that puts many of us in a better mood. But why do we notice such a shift in our feelings and emotions when the seasons change? It turns out that there actually are scientific reasons you're happier in the summer; the warm weather and your sunny mood are no coincidence. It's rather common to feel more satisfied during the hotter, brighter months, and when this season gives way to the longer, darker days of winter (depending on where you live, of course), we'll once again experience a shift.

I personally noticed a huge change when I moved from Michigan to Las Vegas earlier in my 20s. In Michigan, rain is abundant. You're frequently stuck under a ceiling of gloomy clouds. Summers are short and winters are long, freezing, and downright brutal. There are days when it's too cold to be outside, and driving is pretty much impossible due to the snow. But upon arriving in the desert, where it almost always feels like summer and the air is hot and dry, I immediately picked up on something: People here seem happier.

So what is it about summer that puts us so at peace? Why are we so much happier this time of year? Here's what we know:

1. Our Sleeping Habits Change Due To Light Exposure

The number of hours of daytime and nighttime have been found to have an effect on how and when we sleep. One study compared Norway (a country with large seasonal variation) to Ghana (a country with little seasonal variation). During the summer months in Norway, not only did people go to bed earlier and wake up earlier, but the rates of insomnia and fatigue were noticeably lower than in the winter. These differences were not noted in Ghana.

2. Our Eating Habits Change In The Summer, Too

There are a couple of possible explanations for this one. One of the more simple reasons is that with the holidays of the winter seasons, certain types of foods are more abundant and frequent. But it goes deeper than that: It could actually come down to biology — our bodies' primitive instinct is to stockpile and store up for the winter months ahead. One study found that both our eating habits and our body weight change by season, with people consuming on average 86 more calories each day in the fall, compared to spring. Fall also brought more fatty foods than spring. None of this is to say that the foods we eat in the winter are "worse" than the foods we eat in the summer, by the way; they're just different, and they affect us in different ways.

3. Sunshine Can Be Great For Our Bodies

It goes without saying that there are very real, very scary risks associated with sun exposure, and that protecting yourself from harmful UV rays is tantamount. But sunlight is also quite vital to our health and happiness, and when you use it correctly, the benefits are significant. For instance, when you get sunlight, your body produces vitamin D from cholesterol, which helps your body absorb calcium. This is important for our bone health.

Additionally, studies have found a strong correlation between insufficient levels of vitamin D and higher chances of dying from heart disease or cancer, specifically breast and prostate. These studies found that vitamin D from the sun and food was far more essential than the vitamin D you can get with supplements. In fact, they found that there might not be any clear advantage to supplementing it at all.

And let's not forget Seasonal Affective Disorder, or SAD, a type of depression which is generally much more common in the winter than in the summer. A widely accepted solution to this depression is greater exposure to natural light. In fact, in cases where this is not really an option, doctors might prescribe phototherapy, which exposes patients to light that is similar to the sun.

This all but confirms for us that natural vitamin D — and thus, safe sunlight exposure (around 15 minutes for people with lighter skin tones and a little more for people with darker ones) — is a must. The problem is that as many as a billion people in the world are likely vitamin D deficient. Our lives are busy and hectic, but we have to find a way to get a little sunshine in our lives.

At the end of the day, much of this information has one common underlying theme: SAD. The length of daytime and nighttime, and our exposure to light have such an enormous effect on our biological clocks, levels of serotonin (which effects our mood), and levels of melatonin (which work with mood and sleep). It's easy to understand why summer is such a better time for many of us.

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