Today, weather apps provide estimates of outdoor air quality, and the government’s own air quality monitoring website, AirNow, has an easy-to-use zip code portal and fire and smoke map. There are real health benefits to owning an air quality monitor. Photograph: Lisa Wood ShapiroOutdoor air quality monitors are not just for understanding the air quality when the odor of smoke fills your home—an outdoor monitor can keep you informed. Like face masks and air purifiers, an outdoor air quality monitor is no longer a niche appliance but an electronic canary in the modern coal mine of a bad-air world. Photograph: Lisa Wood Shapiro PurpleAir Zen $299 PurpleairBack in January, I woke up to find my PurpleAir Zen outdoor air quality monitor glowing bright red.