Environment Canada has issued a heat warning for all of southern Ontario.

The weather agency says afternoon temperatures in the low to mid-30s with humidex values of 40 or higher are forecast through to Saturday.

Environment Canada says, "extreme heat affects everyone" and warns that the risks are higher for young children, older adults and people with chronic illnesses.

The extreme heat brings with it the potential for unsettled weather. We could see thunderstorms both Friday and Saturday across Simcoe County.

The heatwave will last until Sunday when cooler and less humid air will arrive.

Cooling centres are available to the public in the following cities:

Barrie

  • For more information, click here

Bracebridge

  • Bracebridge Public Library - 94 Manitoba St.
  • Bracebridge Sportsplex (Lobby only) - 110 Clearbrook Trail

Innisfil

  • Innisfil Recreational Complex - 7315 Yonge St.
  • Innisfil Town Hall - 2101 Innisfil Beach Road

Orillia

  • Orillia Public Library - 36 Mississaga St. W
  • Rotary Place - 100 University Ave.
  • Orillia City Centre - 50 Andrew St. S.

Collingwood

  • Collingwood Public Library - 55 Ste. Marie St.
  • Centennial Aquatic Centre - 451 Third St.
  • Central Park Arena - 85 Paterson St.
  • Museum/Station - 45 St. Paul's Street
  • Transit Terminal - Second Street & Pine Street

Owen Sound

  • Owen Sound & Grey Union Public Library
  • Julie McArthur Regional Recreation Centre/TMCA Shared Corridor
  • Bayshore Community Centre
  • Owen Sound City Hall
  • Barclay Room at Owen Sound Police Services

- With files from The Canadian Press