There's actual data on this. The correlation between summer and increased violent crime is real. http://www.bjs.gov/content/pub/pdf/spcvt.pdf

Spike Lee's first famous movie was about this.

And it captures the feeling of heat putting everyone on a hair trigger very well.

For those wondering - Do the Right Thing (1989)

I resent your cheap and illogical attack on my country and my people. I'm an American and I don't run around with firearms killing people.

More crimes happen in the warmer months because more people are active, outside, and interacting with each other.

See this data from the UK And this graph [2]

[1] http://www.ukcrimestats.com/National_Picture/ [2] http://imgur.com/a/Qxm4F

I always figured this was because when it's cold out, people simply go outside less.

They also go out less and there's less crime when it's raining.

> I remember reading an anecdote somewhere that when it's hot out (temperature wise) that physical altercations increase.

This is actually a joke among New Yorkers. Random slashing in the news in May? "Well, it's getting warmer out..."

Unfortunately it's kind of a joke here in Chicago too. You'll hear everyone saying "Suns out guns out" and crap like that. Especially holiday weekends are the worst. I'm not sure why it's this way, but I have a cop neighbor and he tells me summer holiday weekends are the worst for the force. Tons of overtime to be had and tons of hooligans shooting each other. This year the police union told the officers not to take overtime [1]. Unfortunately I'm worried it will end up in more shootings.

1. http://wgntv.com/2016/09/01/police-union-tells-cops-to-avoid...

Heh, "suns out guns out" in my part of the world means you can wear tank tops to show off your muscles 'guns'.

For all the flak Chicago gets in the news for gun deaths, on a per capita basis it's fun death rate is actually a lot better than many other cities in the US.

http://www.citylab.com/politics/2013/01/gun-violence-us-citi...

In one of the machine learning classes we looked at crime data in our city and discovered interesting patterns in how crime seemed to migrate with the seasons. It increased in the summer in some areas, then decreased and moved in the colder months.

Tough to drive-by shoot with a foot of snow on the ground?

Ride-by on a reindeer sleigh? ;-)

> I remember reading an anecdote somewhere that when it's hot out (temperature wise) that physical altercations increase.

The 'build up' to the wet monsoonal season where I am in tropical Australia is well known as 'Mango Madness' season (it coincides with the mango fruiting season).

I have two sisters in the police force, my dad was a doctor and my wife is a psychologist. They all concur that the rate of murders, assaults, domestic violence, divorces, street violence, car accidents etc. all dramatically increase during these couple of months.

When I went on a guided tour through Dubrovnik the guide said -- and I'm paraphrasing her from memory -- that assaults carried more lenient sentences during the warmest parts of summer.

Looks like being cool-headed is more than a metaphor.

Mate from Darwin calls it "suicide season".

most USA city jails pipe in cold air during summers..under 60f due to such things