Feeling a bit grumpy today?
Well, you may not be able to blame it on the bitterly cold temperature outside. (For readers not in Minnesota, our expected high temp today is going to be a lung-bracing 6 degrees. Go ahead. Gloat.)
According to a German study published late last year, daily weather variables, including temperature, have only a very small effect on our mood.
Yes, that finding surprised many people, including the study’s authors. But, then, very few good studies have been conducted to date on this topic. We assume we’re happier on warm, sunny days. But, of course, assumptions aren’t science.
The German study asked 1,233 people to answer daily online questionnaires about their emotions, both positive and negative, and about their energy levels (how tired they felt). These reports were then compared with national weather data. Six weather parameters were studied: temperature, wind, sunlight, precipitation, air pressure, and length of daylight (photoperiod).
After crunching all the numbers, the researchers concluded that “weather fluctuations accounted for very little variance in people’s day-to-day mood.” The only noticeable effect: Sunlight tended to cause people to feel less tired.
Two earlier, but smaller, U.S. studies came to similar conclusions.
A key thing to remember: These studies explored the effect of daily, not seasonal, weather on mood.So they don’t reflect the depression that accompanies seasonal affective disorder (SAD), a winter-related mood disorder that appears to be associated with shorter days (less sunlight), not changing weather patterns.
Possible explanations
If this study’s findings are correct (and the study had it limitations, including the self-reporting of the participants), why then do so many of us believe that daily weather impacts our mood? Here are a couple possible explanations from the study’s authors:
[I]t may be that these beliefs are a reflection of our historical (and possibly culturally transmitted) past, when people were much more dependent on weather-related phenomena (e.g., for shelter and food). It may also be that the discrepancy is because of a small number of extreme cases (e.g., individuals with SAD) who indeed report a strong association between weather and mood. Such cases may leave a very vivid impression on others.
A spring zeitgeber?
Still, this research doesn’t explain the palpable, collective rise in mood experienced by Minnesotans every spring as soon as the outside temperature climbs above 40 degrees.
You know — those days when the ice is still on the lakes, but people are roaming around outside in T-shirts and shorts.
I’ve finally found a study (one of the smaller ones that support the German study) that may explain such nutty (to transplants, like me) behavior. It reported an association between pleasant weather in the spring (but not at other times of the year) and three psychological “lifts”: a more positive mood, a better memory and a greater, as the researchers put it, “openness to new information.”
“[P]leasant springtime weather is a zeitgeber for changing mood and cognition from their wintertime settings back to their baseline settings,” wrote the study’s authors. “If future work continues to support the hypotheses of this article, the behavior prescription is straightforward: If you wish to reap the psychological benefits of good springtime weather, go outside.”
Something to look forward to on this oh-so-spine-chillingly-cold December day.
