As most of the nation suffers through some of the hottest temperatures on record this summer, people are asking the question of how exactly does weather impact our mood. For instance, how does hot weather affect our mood? Does it make us more aggressive — or even more violent?

Does rain make us sad? How about cold temperatures… do they make us feel more like wanting to hunker down, hibernate, and isolate ourselves from others?

Let’s revisit how weather affects our mood and impacts our lives.

I last covered this topic a few years ago, taking a broad look at the research to see all of the different ways weather impacts our mood. It wasn’t surprising to me to see all the different ways that weather impacts our mood.

One of the findings I want to emphasize from the research, however, is that the weather’s impact on our mood may not be as great as we sometimes believe it to be. A lot of the research in this area has found variable, sometimes-conflicting results. So broad, general take-aways are not always to be had.

With that said, here are the various ways that research says weather impacts our mood:

Higher temperatures can bring a depressed person up.

Denissen et al. (2008) found that weather’s daily influence has more of an impact on a person’s negative mood, rather than helping one’s positive mood. Higher temperatures were associated with an increase in a person’s negative feelings, feelings such as being more irritable, distressed, or jittery. The researchers also found that greater amounts of sunlight and less amounts of wind decreased these negative feelings.

The overall effects found by this study were small, however. Furthermore, researchers found no significant effect on weather improving a person’s positive mood.

Seasonal affective disorder is real.

Seasonal affective disorder (SAD) is a very real kind of depressive disorder (technically referred to as a depressive disorder with seasonal pattern) wherein a person’s major depressive episode is connected to a specific season. While we most commonly think of SAD affecting only people in the fall or winter months, a minority of people also experience SAD during the spring and summer months too.

Heat (and extreme rain) brings out the worst in people.

Hsiang et al. (2013) found a link between human aggression and higher temperatures. As temperatures rose, the researchers noted that intergroup conflicts also tended to jump — by 14 percent (a significant increase). The scientists also found interpersonal violence rose by 4 percent.

These findings held true not only for higher temperatures, but also that wet stuff that falls from the sky — rain. The more it rained (especially in areas where high rainfall is not expected), the more aggressive people seemed to get. However, this research could only show a correlation between the two. It’s not at all clear that weather causes these things to happen.

Other research has confirmed this finding. For instance, researcher Marie Connolly (2013) found that women who were interviewed on days “with more rain and higher temperatures [reported] statistically and substantively decreasing life satisfaction, consistent with the affect results.” On days with lower temperatures and no rain, the same subjects reported higher life satisfaction.

Suicides peak during the spring & summer.

While springtime may be the season of hope for many, it’s the season of hopeless for those who are depressed. Perhaps buoyed by the increase in daylight and warmer temperatures, researchers (Koskinen et al., 2002) found that outdoor workers were far more likely to commit suicide in the spring months than during the winter months. For indoor workers studied, suicides peaked in the summertime.

A comprehensive meta-analysis performed in 2012 (Christodoulou et al.) on the seasonality of suicide found a universal truth: “Studies from both the Norther and Southern hemisphere report a seasonal pattern for suicides. Thus, it seems that seasonality is observed with an increase in suicides for spring and early summer and an analogous decrease during autumn and winter months, that is a constant, if not a universal behavior that affects both the Norther and Southern hemisphere.”

A Swedish study (Makris et al., 2013) that examined all suicides in the country from 1992 to 2003 found a similar spring-summer seasonal pattern peak for suicides as well — especially those treated with an SSRI antidepressant.

The Impact of Weather May Depend On Your Weather Personality Type

Klimstra et al. (2011) found that half of the 415 adolescents studied weren’t really impacted much at all by changes in the weather, while the other half were. Further analyses determined the following weather personality types:

  • Summer lovers (17 percent) – “Happier, less fearful, and less angry on days with more sunshine and higher temperatures. More hours of precipitation was associated with less happiness and more anxiety and anger.”
  • Summer haters (27 percent) – “Less happy and more fearful and angry when the temperature and the percentage of sunshine were higher. With more hours of precipitation they tended to be happier and less fearful and angry.”
  • Rain haters (9 percent) – “Angrier and less happy on days with more precipitation. By comparison, they were more happy and fearful, but less angry, on days with more sunshine and higher temperatures.”
  • Unaffected by weather (48 percent) – Largely unimpacted by changes in the weather.

We need to keep in mind that this weather personality type analysis was done only on Dutch teenagers — meaning we don’t know how generalizable the results are to adults and people living in other countries. But it potentially sheds some light on the conflicting research into how weather impacts our mood. Maybe the reason some researchers have a hard time finding a meaningful correlation is because it depends on what kind of weather personality you are studying.

Weather Doesn’t Have to Impact Your Mood

Connolly (2008) found that men responded to unexpected weather by simply changing their plans. Raining? Let’s stay in instead of going for a hike. Unexpectedly warm day? Let’s take advantage of it by going to the water park or beach. Women, on the other hand, didn’t seem as likely to modify their activities, thereby more often taking the brunt of the unexpected weather on their mood.

Weather seems to have a real and measurable impact on many people’s mood, but is dependent upon many factors. The impact of the weather is probably going to be greater in any geographic location that experiences lengthy periods of unusual weather. For instance, if it’s hot and sunny for months on end, that’s probably going to make more of an impact in Seattle (a usually rainy and cool place to live) than in Miami (a usually hot and sunny place to live). It may also depend upon your “weather personality type,” but that needs further research to confirm.