St. Catharines: Hourly Fine Particulate Matter PM2.5 Concentrations

From March 29, 2023 EDT to March 31, 2023 EDT.


  • Effective January 1, 2013, the PM2.5 monitoring method was changed in Ontario. For more information, visit Frequently Asked Questions.
  • The pollutant concentrations on this web page are based on automatically polled data and have not undergone final verification.

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