The Air Quality Index around southwest Montana was bad all weekend. Then it became even worse on Monday into seriously unhealthy levels.

When I woke up this morning, the AQI in Bozeman was 173. For a little perspective, the AQI in Beijing, China is 86 and the AQI in Mexico City is 84 and those two cities are known for terrible air quality every day.

By late morning on Monday, the AQI around the Gallatin Valley had improved slightly to the 150s, which is still unhealthy.

iqAir

The Air Quality Index ranges from 0 to 500, with 500 being the worst quality air. When numbers are 50 or below, the air quality is generally pretty healthy. Numbers below 100 are regarded as 'satisfactory'. Above 100, the air quality is then labeled as 'unhealthy' in a few categories.

According to AirNow.gov, AQI levels are also chopped up into special color codes as described below:

  • Green: Good 0 to 50 Air quality is satisfactory, and air pollution poses little or no risk.
  • Yellow: Moderate 51 to 100 Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.
  • Orange: Unhealthy for Sensitive Groups 101 to 150 Members of sensitive groups may experience health effects. The general public is less likely to be affected.
  • Red: Unhealthy 151 to 200 Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.
  • Purple: Very Unhealthy 201 to 300 Health alert: The risk of health effects is increased for everyone.
  • Maroon: Hazardous 301 and higher Health warning of emergency conditions: everyone is more likely to be affected.

LOOK: TV Locations in Every State