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