Extreme Heat, Humidity and Smog

Environment Canada will issue a Heat Warning when the temperature is expected to reach 30°C (86°F) or more and the Humidex value (how hot, humid weather feels to the average person) is expected to reach 40°C (104°F) or more.

Halton Region Health Department will issue a Heat Alert in response to an Environment Canada warning. Vulnerable populations — older adults, infants and young children, people with chronic illness and outdoor workers — are at greatest risk from extreme heat. Smog and related health risks can often accompany extreme heat.

To learn more about how local air quality impacts human health visit the town’s Smog, Heat and Weather Alert page.

If a Heat Alert is issued, please visit the Heat Alert page for information on our cooling centres.


  • Develop an emergency plan so every member of your household knows what to do during extreme heat.
  • Make sure you have an emergency kit ready with extra water, sunscreen with a high SPF and sunglasses.
  • Stay informed – sign up for heat alerts from Halton Region Health Department.
  • Learn about the health effects of extreme heat and how to treat heat-related illnesses from Halton Region Health Department.
  • Make sure your central air conditioning unit is working properly.
  • Consider installing ceiling fans, window air conditioners or purchasing portable fans.
  • Cover windows that receive morning or afternoon sun with drapes, shades or awnings.
  • Be prepared for a power outage due to higher than average use of electricity.


  • Stay indoors as much as possible to limit exposure to the sun and heat.
  • Maintain a comfortable temperature with central air conditioning or fans.
  • Stay on the lowest floor, in shaded areas, if air conditioning is not available.
  • Avoid using the oven or other heat-producing appliances.
  • Turn off lights, computers, stereos and televisions when not being used.
  • Check on family, friends, and neighbours who do not have air conditioning and who may need assistance.
  • Visit air conditioned public places, Town of Oakville swimming pools, splash pads or cooling centres.
  • Drink plenty of fluids (water is recommended). Avoid caffeine beverages.
  • Stay in the shade and avoid strenuous physical activities.
  • Do not leave children or pets in parked vehicles.

Power outage

Know what to do in case of a power outage. Visit our Power Outage page for more information.


Refill your emergency kit and update your household emergency plan, if needed.

Other resources

Visit Environment Canada's public weather alert website.

Subscribe to smog alerts from the Ontario Ministry of the Environment.

Visit the Emergency Management Ontario website, the Federal Government's Get Prepared website, and the Halton Region website.

Visit the Climate Change Adaptation Initiative page for the Town of Oakville's Climate Change Primer.