Can the weather impact your mood? The answer’s “Yes.” In fact, weather-related mood changes can be as unpredictable as, well, the weather.

For example, research shows that spring sunshine causes changes in brain chemistry that make us happier. But when the temperatures make us sweat, sunshine can actually make us irritable and aggressive. Here are 3 other ways the weather can affect our moods: 

  • First: The variable that has the biggest impact on our mood is: Humidity. When the humidity’s high, people report being less satisfied with their lives. That’s because our bodies have to work harder to cool us down, which leaves our brains with less energy, and that makes it harder to concentrate, and makes us much more tired. 

  • Next: Rainy days really do get us down, but not for the reason we think. A study in The American Journal of Psychology found that the mood dip on rainy days isn’t about precipitation, it’s about the lack of sunlight. Because when it’s cloudy, our brain’s pineal gland produces more of the sleep hormone melatonin, which can make us drowsy and depressed. Luckily, you can beat the blues on rainy days by turning on a few extra lights first thing in the morning. 

  • The final way weather impacts our mood: Wind can make us unhappy. Studies show that the changes in barometric pressure connected to strong winds can cause headaches, joint pain, fatigue, and irritability. No one knows the exact reasons why, but scientists think it has something to do with the way our joints and blood vessels shrink and swell as the barometric pressure changes.