Warm weather and sunny days make millions of people clinically depressed every year. It’s called summer-onset seasonal affective disorder. We typically associate Seasonal Affective Disorder, SAD, with the shorter and colder days of winter. But it can also strike in the summer. 

In fact, one in 50 people experience the summer version of Seasonal Affective Disorder. But whereas wintertime SAD makes people feel lethargic, summertime SAD makes people feel agitated. You may feel too jittery to eat, sleep or follow your usual routines. 

Dr. Norman Rosenthal is a psychiatrist with the National Institute for Mental Health. And he says, just like shorter days and less sunlight in winter can throw off your circadian rhythm or body clock, summer can work the same way. That’s especially true in Northern areas, where it can stay light well into the night because that throws off your sleep hormones. But when you’re overtired, your body releases more of the stress hormone, cortisol. And that can contribute to depression and increase emotional sensitivity.

Hot weather can also contribute to insomnia because our body has a harder time cooling down and producing sleep hormones that can make depressive symptoms worse.

Summertime SAD can also be exacerbated if you have body image issues. When everyone is running around in tank tops and bathing suits, people with body image issues become acutely aware that they don’t fit in or feel comfortable. Heat can also be a SAD trigger because it increases agitation. 

So what can you do? Start by talking to a mental health professional. You can also wear sunglasses to limit light exposure and keep a strict sleep/wake schedule. That’ll get your sleep hormones regulated. And stay in air-conditioning as much as possible to combat the agitation that comes with hot and humid weather.