Culture

How to Measure Summer in Your City

Designers in Vienna created sensors for BBQ smoke, sunscreen, and other telltale signs of the season.
Two kids play in the spray from a fire hydrant during a D.C. heat wave. (AP Photo/Lawrence Jackson)

How do you know when summer has arrived? There are the objective measures, of course: the mercury rising, the pools opening, the observance of Memorial Day. But for many of us, it’s a range of visceral signals, tied to the cities we live in, that officially usher in shorts and swimsuit weather—from the brief respite from umbrellas in Seattle to the influx of sweaty, bewildered interns in Washington, D.C.