Chicago’s Air Quality Scare: Mistake in Weather Apps

On Wednesday morning, April 23, many people in Chicago got really worried when popular weather apps said the air was unsafe to breathe. Google’s air quality map showed Chicago had the worst air quality in the country, and Apple’s weather app showed scary numbers in the 400s, which is extremely hazardous. Because of this, many people decided to stay indoors.

Madeline Blair, who is 24, saw the warning on her Apple weather app and chose to skip her morning exercise. She went to her basement to grab her air filter instead. “I live on the northwest side, and the map showed my area in dark purple, so I thought, ‘No thanks, I’m just staying inside,’” she said.

Savannah Bhojwani, 26, from Old Town, was shocked by the numbers too. She shared screenshots of the readings with her friends. At 10 a.m., her Apple weather app showed the air quality reaching the 200s and then rising into the 400s. Although she thought those numbers might be wrong, the dark, cloudy weather made her unsure. One of her friends wondered if it was a garage fire, while another thought maybe there was a gas leak. But they couldn’t find any news about it.

Others on social media were worried too and started guessing what caused the bad air quality. This all happened shortly after the American Lung Association said that Chicago had the 15th worst ozone pollution in the country, with Los Angeles being the worst.

However, not everyone was worried. The Environmental Protection Agency’s AirNow and a service called PurpleAir said that the air quality in Chicago was good.

Later in the day, the Chicago Department of Public Health confirmed that the air was actually safe. They didn’t explain why the apps had shown dangerous levels. Both Apple and Google get their air quality information from a company called BreezoMeter. This company, which Google bought in 2022, uses similar sensors as AirNow and PurpleAir, but also combines data from other sources.

Savannah realized it was just a mistake when the sun came out but her Apple app still showed bad air. “This is clearly inaccurate,” she thought. Madeline Blair also felt the same way. “Now the weather is nice. I’m about to go get coffee with a friend before a poetry reading,” she said just before 4 p.m. “So you could say I’m going back to normal activities.”

Abigail Jaffe, a spokesperson for Google, explained that the high readings were due to “a third-party monitoring station inaccurately reporting high measurements.” By 5 p.m., both Google and Apple finally showed good air quality in Chicago.