Are there any statistics indicating a relationship between crime and the weather?

Dear Matthew Alice:

Lately I've gotten calls from around the country from people wanting to know if San Diego's good weather has something to do with our falling crime rate. I have to tell them I don't know. Are there any statistics indicating a relationship between crime and the weather?

-- Bill Robinson, San Diego Police Department

So they figure all our burglars have retired to the beach? That's just our well-polished image; it can't have anything to do with logic. To some poor jamoke in Baltimore, we probably seem like the Promised Land or a Corona beer commercial. Who would foul this paradise by committing a crime? Anyway, who would have the energy to get up off their lounge chair? Why, even our killer whales become smiling pussycats. Not one of em with a rap sheet.

True, San Diego's crime rate has dropped steadily in most categories since the early 90s, but we're just part of a nationwide trend, according to FBI statistics. Explanations offered include the strong economy; the increase in community policing; fewer people in the crime-prone years (teens and early-20s); tougher sentencing laws (repeat offenders account for a big chunk of any city's crime rate)-- none of them proven. If San Diego's crime rate were related to its weather (actually, more correctly, its climate, since San Diego doesn't actually have weather), then you'd expect to see some equivalent change over the past ten years. But other than the dry spell we're in, things today look pretty much like they did in 1990.

The only study the elves could find linking weather and crime rates comes out of the University of Missouri. In a nationwide survey, they concluded that the rate will go up with statistical reliability during heat waves. But consider that a "heat wave" in San Diego is a well-behaved little Santa Ana. In Chicago or Atlanta or St. Louis, a heat wave means it's 110 in the daytime, 95 at night, humidity in the 90s, and after four or five days of this, even yoga masters turn into ax murderers. So if the jamoke in Baltimore was counting on global warming to pacify the populace, maybe he has another thing coming.

Matthew Alice, Pants on Fire

Dear Matthew Alice:

In your reply about the correlation of crime statistics and the weather, you talk about a heat wave in some Eastern U.S. cities as being "110 in the daytime, 95 at night, humidity in the 90s...." In fact, these conditions almost never occur in the U.S., even in Florida or the Gulf Coast. I think people must have started this rumor when they compared early-morning humidities and late-afternoon temperatures. To have 90% humidity at 90 degrees requires a dewpoint of 86 degrees, and it's not often you'll see dew form at 86 degrees. And in the same response, you said, "...maybe he has another thing coming." Isn't the phrase, "He has another think coming"?

-- Weather Geek, Alpine

Yes, it is. Matthew Alice, the cliché geek, actually wrote "another think coming," then sent the column off to be chiseled into type. Somewhere in the mysterious void between me and the printed page, "think" transformed itself into "thing." That's just a little backstage peek at how big-time journalism works. These thinks happen. As for the illustration of an East Coast heat wave, well, I did pull those numbers out of that same mysterious void without doing the dewpoint math. In the writing-geek game, it's called hyperbole. To a weather geek, it's just a big fat lie.