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No kidding – humans happier on sunny days, perfect temp is 25C, freezing days similar to terrorist attacks on US mood

By Jo Nova

New research looking at three and a half billion social media posts from tens of millions of individuals showed the very unshocking result that people are happiest on sunny clear days around 25C. Facebook and Twitter comments on those days used more positive, fun terms. Days below 20, above 30, that were cloudy or had a humidity above 80% put people in a less happy mood. So did terrorist events, and the effects of weather were pretty comparable. Temperatures that are below freezing put a real dampener on expressions of positive sentiment. (The next ice age is going to be no fun.)

Peak positive occurs in the mid to high twenties and on days with zero mm of rain.

ENSO, ONI Graph, 2009-2018

The effect of temperature and rain on Facebook and Twitter moods in the US.

Some people have a sunny disposition, others have cloudy faces and everyone over two knows what those expressions mean.

If our aim is to maximize human happiness and productivity, shouldn’t the UN Weather Control Committee (IPCC) be aiming to reduce freezing days and maximize the zone of 25C days on areas with the highest population density?

Judging by this awesome Hedonometer graph, during the hottest ever year of 2016, people were pretty happy.

Hedonometer, Happiness, Twitter, graph.

…Hedonometer, Happiness, Twitter, graph.

Just cross checking that with the ENSO effect, perhaps we should also be working to increase El Nino years?

As for terrorism, conditions that were below freezing were comparable to the Sept 11 anniversary (in the US) and actual attacks, floods and earthquakes were even worse. Clearly, Daylight Savings time should only start, and never end. We all need the extra hour of sleep.

Terrorism, cold weather, mood.


But keep in mind the y axis scale on the top graph. We’re talking about 2 percent less “happy thoughts” on a zero degree day. It sounds tiny, though on a national scale I expect it would translate to slightly higher cortisol levels, more stress, less health, and lower productivity.

Joe Pinkstone at the Daily Mail sees the cold threat: Cold weather is MORE depressing to people than a terrorist attack, claim scientists

Alan Martin at Alphr warns us about the heat: High temperatures make us hotheads: Study finds the weather impacts how we “talk” on Twitter and Facebook. “Blame it on the sunshine”.

A few caveats:

  • Sarcasm and irony would skew these results and there “might” be some of that on Twitter. ;-)
  • Researchers think the results may underestimate the effect of weather because they are looking at a self selecting younger slice of the population which use Twitter and Facebook.
  • They also acknowledge that their research was only done on the US where air conditioners are common, and a study of poorer nations may have an even more pronounced effect.

From the Daily Mail:

Dr Obradovich said: ‘We conducted the largest ever investigation into the relationship between meteorological conditions and the sentiment of human expressions. ‘We find that how we express ourselves is shaped by the weather outside. ‘Adverse weather conditions – hot and cold temperatures, precipitation, added humidity, and increased cloud cover – reduce the sentiment of human expressions across billions of social media posts drawn from millions of US residents.’ In particular, experts found that rain was associated with a more negatively expressed sentiment.