Overview

• This third heat warning of the summer covers southern and eastern Ontario from Windsor through Cornwall, including Ottawa and Kingston, until next Thursday.
• Daytime temperatures are forecast between 29°C and 32°C with humidex values making it feel like 35°C to 40°C.
• Overnight lows of 19°C to 23°C will provide little relief from the heat.
• The weather agency expects Saturday to be the hottest day of the stretch.
• Health officials advise frequent hydration, monitoring for heat exhaustion, and checking on seniors and other at-risk individuals.