The City of St. Catharines joins municipalities and governments across the province and the country in recognizing the following commemorative dates with the lowering of flags to half-mast.
- January 27: International Holocaust Remembrance Day
- April 9: Vimy Ridge Day
- April 28: National Day of Mourning
- June 23: National Day of Remembrance for Victims of Terrorism
- Second Sunday in September: Firefighters’ National Memorial Day (unless half-masting occurs near the place where a memorial is being observed; in this case, half-masting occurs until sunset according to the prescribed order of service).
- Last Sunday in September: Police and Peace Officers' National Memorial Day (unless half-masting occurs near the place where a memorial is being observed; in this case, half-masting occurs until sunset according to the prescribed order of service).
- September 30: National Day for Truth and Reconciliation
- November 8: Indigenous Veterans Day
- November 11: Remembrance Day
- Half-masting occurs at 11 a.m. or according to the prescribed order of service at or near a cenotaph or another site where services are being observed.
- Flags are lowered to half-mast at the beginning of the Remembrance Day service at City Hall at 11 a.m. and are raised again at the end of the service. City staff lower the flags to half-mast again a half-hour later, and they remain at half-mast until sunset.
- December 6: National Day of Remembrance and Action on Violence Against Women