Why do we feel so happy when the sun is out?
Spring has sprung. The sun is out just a little more often each day, flowers are starting to blossom, and some trees are budding. I’m sure many of you are familiar with the following experience – maybe you’re walking to school, crossing to the AWC, or just on a stroll in your free time and suddenly the sun comes out. If you’re anything like me, you’ll probably feel your mood instantly change, feel more energized and happier once the sun hits your face. The slow emergence of spring has sparked a lot of casual discourse about how warmer, sunnier weather makes us feel. I’ve even overheard people say that it feels like their problems go away once the sun comes out. This correlation between sun and happiness goes the opposite way too – dark weather and sadness. For many, the winter months are associated with negative emotions of loneliness, dreariness, and upset. In extreme cases, this is known as Seasonal Affective Disorder (SAD) in which an individual experiences depression, most often during the fall and winter months, due to chemical changes in the brain that induce depression.
The explanation behind weather-dependent emotions is quite simple and has to do with scientific ideas you are probably already familiar with. Exposure to sunlight is shown to increase the brain’s release of a hormone called serotonin, which is known colloquially as a “feel-good chemical” in your brain. The serotonin hormone has been shown to influence learning abilities, memory, happiness, body temperature, sleep, sexual behavior, hunger, and gut function. Serotonin can otherwise be released from spending time with loved ones, eating a balanced diet, exercising, and participating in group activities. One study from Australia found that people had higher serotonin levels on sunny days than on cloudy ones. This was true no matter the temperature or other conditions. So, in the spring and summertime, when the sun is out, the weather is warm, and the days are long, people generally feel happier, healthier, and more energetic.
The same is true for the inverse. Seasonal depression is linked with less sunlight and shorter days, due to lack of serotonin from the sun and increased melatonin. You may be familiar with melatonin in the form of supplements for sleep, but naturally, it is a chemical that your body produces in response to darkness to signal to your body that it is time to sleep. At night, when our bodies register darkness and decreased light, they produce melatonin which explains the feelings of lethargy, sadness, dreariness, and tiredness throughout the winter.
These feelings of euphoria on sunny days and sadness during cloudy days might feel pseudo-scientific but they have a really strong and well-researched scientific base. Seasonal affective disorder and sun-induced euphoria are both strong examples of how much weather can impact our hormones, mood, and energy, which is important to keep in mind as we enter the spring and summer seasons.
Sources
https://www.healthline.com/health/depression/benefits-sunlight#_noHeaderPrefixedContent
https://time.com/collection/guide-to-happiness/4888327/why-sunlight-is-so-good-for-you