Linda Poon is a staff writer at CityLab covering science and urban technology, including smart cities and climate change. She previously covered global health and development for NPR’s Goats and Soda blog.
Underground temperatures can soar as high as 106 degrees.
As a summer commuter, you have to get creative about weathering heat waves without showing up to work drenched in sweat. Stick to airy clothing, stay hydrated, and maybe try convincing your boss that shorts are appropriate office attire. And then get choosy about your subway stations.
Temperatures in New York City clocked in at a sweltering 96 degrees Wednesday, making it the city’s hottest day of the year so far. But where New Yorkers really felt the heat was below ground, in one of the city’s many increasingly unbearble subway stations.
Just how hot can these stations get?
A new interactive map from radio station WNYC reveals that temperatures on the platform yesterday hit as high as 106.6 degrees Fahrenheit, which was what the team recorded at the Brooklyn Bridge-City Hall 4/5/6 station. The coolest, or “most pleasant,” platform was at 5th Ave.-59th St. on the N/Q/R line, which measured 68 degrees.
Using consumer-grade temperature sensors, a team of four people went to 103 stations south of Central Park between 5:30 and 7:30 p.m. In that window, the temperature outside hovered around the mid-80s. Carrying out the experiment on this year’s hottest day in NYC was actually a coincidence, says John Keefe, senior editor of WNYC’s data news team.
The team, which included Keefe, another staff member, and two lucky interns, moved away from the air conditioning blasting from inside the trains and measured at ground level to get consistent readings. Even so, Keefe notes, the temperatures recorded are likely a little cooler than what commuters actually felt on their face. That’s because heat tends to rise and the humidity always makes things worse.
In part, the hot platforms are a trade-off for that cool blast of air conditioning inside the trains themselves. It appeared that the hottest stations were “where trains are idling for longer period of times,” Keefe says. “The air conditioning is still running inside the train, but the heat is being transferred outside and dumped onto the platform.”
On the other hand, the coolest stations tended to be at stations closer to the street level where there’s better ventilation and at the end of the line, where trains don’t come through as often.
As summer soldiers on, NYC commuters have been getting antsy about the increasingly unbearable conditions underground. Ideally, New York’s Metropolitan Transport Authority would be able increase ventilation and install some sort of cooling system to every station, but Keefe says that’s easier said than done.
“When we talked to the MTA about this, they know it’s hot,” he says. “The problem is that [adding ventilation] requires some sort of control over the space above the train stations and in many cases the subway system doesn’t [have it].”
For now, Keefe recommends using the map as a tool to avoid hotter stations.