Communities south of the U.S.-Canada border reported air quality index (AQI) readings between 200 and 400 – levels which are considered to be unhealthy to even hazardous.

As of 8 a.m., multiple air quality sensors are reporting readings in the “Unhealthy for Sensitive Groups” (AQI 101–150) to “Unhealthy” (AQI 151–200) range.

Dust pollution in Delhi surged overnight, pushing AQI above 200 into the 'poor' category, with visibility dropping sharply due to strong, dust-laden winds.

The red-level air quality index (AQI) category—covering values from 151 to 200—means the air is unhealthy for everyone, not just vulnerable populations. According to the EPA, ...