At one point, it got about as bad as it gets anywhere: reports indicated that for a few hours that Thursday afternoon, a portion of Minnesota had the worst air quality in the world among major cities. At one point, that area had the worst air quality in the world, surpassing 1,100 on the Air Quality Index. By the time we all left on Sunday after a fun weekend of golf, bags, tequila, and pull tabs, every single one of us had an air quality app on our phone to gauge conditions and protect our health. It's a UN Environment Programme partner, blends government sensors, private sensors, and satellite data, and offers a seven-day forecast. One honest caveat: those are consumer-grade sensors, not official EPA equipment, so the numbers can run a little high.