Air Quality Ontario: Map: Ontario's Air Monitoring Stations, AQHI

Map of Ontario

AQHI observations for Saturday, July 5, 2025, 4:00 pm

Air Quality Health Index categories, values and associated colours
Air Quality Health Index categories and values
1	2	3	4	5	6	7	8	9	10	+
Low risk (1 - 3)			Moderate risk (4 - 6)			High risk (7 - 10)				Very high risk

Note:

The Air Quality Health Index (AQHI) on this web page are based on automatically polled data and have not undergone final verification.
N/A (not available) denotes invalid or missing data.

The table below provides the health messages for each category of the Air Quality Health Index for the "at risk" population and the general population.
Health risk	Air Quality Health Index	Health messages
Health risk	Air Quality Health Index	At risk population*	General population
Low	1 - 3	Enjoy your usual outdoor activities.	Ideal air quality for outdoor activities.
Moderate	4 - 6	Consider reducing or rescheduling strenuous activities outdoors if you are experiencing symptoms.	No need to modify your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.
High	7 - 10	Reduce or reschedule strenuous activities outdoors. Children and the elderly should also take it easy.	Consider reducing or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation.
Very high	Above 10	Avoid strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion.	Reduce or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.

* People with heart or breathing problems are at greater risk. Follow your doctor's usual advice about exercising and managing your condition.

AQHI readings and forecasts are also available on the Environment and Climate Change Canada website.

You can also get AQHI readings from recorded telephone messages by dialing 1-800-387-7768 (toll-free) or 416-246-0411 in Toronto.