Does Hot Weather Make People Aggressive?

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May 28, 2019

We all know that weather can affect our mood; depending on the climate in which you live, a person may have a personal preference for a particular kind of weather. If you get a lot of rain, you may really enjoy brief moments of sunshine, and if you live in a predominantly hot, sunny place, you may crave the times that there is a little rain or a cool breeze. Summer is creeping upon us, and in recent years it has been shown that there are significant heat waves in the summer every year in at least one part of the world. The summer heat can be intense; the air can feel thicker, the sun can burn a person’s skin, and people can become generally more irritable as the temperature increases. Researchers have found that summer months are generally associated with more aggressive and violent crimes, and they are constantly trying to assess what may be responsible.


Researchers have found some interesting information about patterns of aggressive human behavior and its relatedness to the summer heat. Studies have shown that there is a link between heat waves and violent or aggressive behavior, increased substance abuse, increased depression symptoms, decreased concentration and quality sleep, and decreased energy levels. All of these things seem interrelated. Lack of sleep has been shown in research to have a significant effect of a person’s mood and behavior and is a contributing affect to a person’s development of depression symptoms generally. Depression is often associated with irritability and sometimes more aggressive behavior, not to mention decreased concentration and overall fatigue. So, is it possible that heat waves contribute to an increase in sleep difficulties and this may lead to the depressive symptoms and aggression seen during these months? Some researchers suggest that this may be the case.

In addition to the lack of sleep hypothesis, researchers are also assessing internal temperature in general and how that could contribute to more violent or aggressive behavior. Anyone who has been angry before knows that there is a correlation between being “heated” internally and feeling angry externally. Angry feelings generally start within the body and involve an increase in body temperature that often facilitates angry outbursts because people cannot tolerate the heat they are feeling inside. Outbursts and other aggressive acts are often used as a way to release the negative and sometimes painful feelings people feel inside when they’re angry. Those who study anger management and teach people how to regulate their emotions often teach a person to decrease their internal body temperature without aggressive acts as a way to calm down or “cool off”. Deep breathing exercises, muscle relaxation exercises, and other techniques are used to regulate the body’s internal temperature and improve their ability to manage their often impulse-driven aggressive behavior.

With this in mind, it makes sense then why a person may be more aggressive in hotter temperatures. When a person struggles to control the external temperature of their bodies, it makes controlling their internal state even more difficult. Being unable to feel cool appears to trigger the “fight or flight” response that accompanies violent and aggressive behavior. From an evolutionary perspective, we have developed some survival instincts that have helped the human species survive over time; these usually involve protection mechanisms like being able to keep self physically safe and healthy (finding food, finding safe place to sleep, etc.). If a person feels that they are in a place where their safety is at stake, they often experience a deep, evolutionary response that scientists call “fight or flight” responses. This means that a person will either fight off the threat, or they will try to escape it in whichever way they can. So, when a person cannot escape intense heat temperatures, their bodies may go into survival mode and choose to engage in more aggressive behavior, attempting to protect themselves from the uncomfortable feeling they experience in the heat.

No matter what the reason is, managing anger during hotter months is more of a challenge. Knowing this can help people who struggle with aggression or violent impulsive behaviors to work to prepare themselves by decreasing the amount of time they spend in excessive heat. Professionals suggest finding ways to keep yourself cool in the warmer months, staying indoors as much as possible and drinking more water to help regulate internal body temperature.

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Dr. Shannon McHugh is a Licensed Clinical and Forensic Psychologist in Los Angeles, California. She specializes in assessment and treatment of children, adolescents, and adults who have developmental and social delays, behavioral difficulties, and those who have experienced traumatic events