AQI: Hazardous

Hazardous AQI (301-500) is the most dangerous level, triggering emergency health warnings. The entire population is affected. Everyone should avoid all outdoor physical activity and stay indoors with air filtration running.

Hazardous AQI is extremely rare in most US cities but has occurred during catastrophic wildfire events in the West, particularly in 2020 and 2023 when smoke from massive fires blanketed cities like Portland, San Francisco, and parts of the Eastern seaboard.

If you have respiratory or cardiovascular conditions, evacuation to an area with better air quality is worth considering. For others, staying indoors with sealed windows and HEPA filtration is the recommended approach unless local authorities issue evacuation orders.

HEPA air purifiers significantly reduce indoor PM2.5 levels and are strongly recommended. Use the highest setting and ensure the purifier is rated for your room size. A DIY box fan with a MERV-13 filter can also help in an emergency.

Even brief exposure can cause respiratory distress, chest pain, headaches, and eye irritation in healthy adults. People with heart or lung conditions face risk of heart attacks, strokes, and severe asthma attacks. Emergency room visits spike during these events.