St. Catharines: current Air Quality Health Index (AQHI)

Calculated at 4:00 am EDT Saturday, October 18, 2025

2

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

Forecast for St. Catharines

• Forecast Air Quality Health Index maximums for St. Catharines
• Issued at: 5:00 pm EDT October 17, 2025

Forecast Air Quality Health Index maximums for St. Catharines

Period	Forecast maximum (Issued at 5:00 pm EDT October 17, 2025)
Friday	2 - Low Risk
Friday night	3 - Low Risk
Saturday	3 - Low Risk

Health message for St. Catharines

• Current Air Quality Health Index: 2
• Calculated at 4:00 am EDT Saturday, October 18, 2025
• Risk: Low

At-risk population:

• Enjoy your usual outdoor activities.
• Find out if you are at risk

General population:

• Ideal air quality for outdoor activities.

See the Ontario Ministry of the Environment, Conservation and Parks air quality health messages.

Note: AQHI readings on this web page are based on automatically polled data and have not undergone final verification.