Extreme weather conditions

When temperatures hit 32°C or more, for three or more days, it’s considered a heat wave or conditions of extreme heat. Poor air quality can cause additional health concerns when extreme heat combines with air pollutants from industry, gas-powered vehicles, and other sources.

When extremely hot temperatures are forecast, the City offers residents places to stay cool in Mississauga. These include visiting one of our swimming pools, air-conditioned libraries, spray pads and community centres.

When a heat warning has been issued by the City, residents are encouraged to call before visiting one of these locations as hours of operation vary.

For more information on extreme heat alerts and how to stay cool, please visit the Peel Region.


Humidex values measure how hot the weather feels to the average person. Under normal conditions, your body produces sweat that evaporates to cool you down. Under extreme heat, the body must work harder to maintain its normal temperature. A humidex advisory is issued when humidex values are expected to reach 40 or more. The higher the humidex, the harder it is for your body to cool itself.

Smog alerts

Smog levels indicate and forecast the current air quality information. Most smog days in Ontario occur between May and September. When an alert is issued, avoid strenuous physical outdoor activities. If you have a heart or lung condition, consult your family doctor on how to keep healthy in the heat.

How to prepare for a heat wave

  • Install window air conditioners, insulate if needed
  • Check air conditioning ducts for proper insulation
  • Install temporary reflectors (aluminium cardboard) to reflect heat back outside
  • Weather-strip doors and windows to keep cool air inside
  • Cover large windows that are in direct sunlight with drapes or shades
  • Stay indoors if you can
  • Drink plenty of water, even if you are not thirsty
  • Dress in loose, light-coloured, lightweight clothing and cover as much skin as possible
  • Use public buildings like libraries, movie theatres, shopping malls, and community facilities that are air-conditioned to cool down

Severe winter weather can pose a threat to life, property, and the environment. It may include ice storms, blizzards and extreme cold, and can result in extended power outages and dangerous road conditions.

There are many ways you can prepare for severe winter weather:

Before the storm

  • Check and restock your 72 hour emergency kit
  • Plan to be without electricity and heat for 72 hours
  • Buy any emergency supplies well in advance. Stores will be busy.
  • Ensure you have snow tires installed well in advance of the winter storm season
  • Make a communications plan. How are you going to get in contact with family if you’re away from home?
  • Plan to check in with neighbours, family, friends and anyone who may need your help or who can help you
  • Prepare a plan to help your family evacuate if needed

During the storm

  • Keep warm and change out of wet clothing. Wear multiple layers, keep plenty of blankets available.
  • Use your 72 hour emergency kit
  • Stay indoors and avoid driving unless absolutely necessary
  • If you must drive, keep on main roads and avoid unplowed side roads
  • Don’t use propane stoves or barbecues indoors as they release carbon monoxide
  • Bring pets indoors and ensure they are dry
  • Consult safety manual when using space heaters
  • Keep heat sources at least three feet away from furniture and curtains
  • Check in with neighbours, family, and friends
  • Evacuate if necessary or if advised to do so from officials

After the storm

  • If you have no power after 72 hours, consider going to an emergency shelter or staying with friends and family.
  • Consult your utility company before reconnecting power and gas
  • Check in with neighbours, family, and friends
  • Safely begin to clear debris around your property, such as fallen tree branches or snow
  • Keep away from any fallen power lines
  • Check with your local waste department for debris collection schedules

Flooding can be caused by heavy rainfall, and it can happen quickly and without warning. Basement flooding can also be caused by plumbing problems, sewer blockages or other back-ups.

Flood warning and forecasting

When a Flood Watch or Warning is in effect, you can help by:

  • Ensuring street catch basins are not blocked and keeping your eaves troughs clear
  • Reporting blocked catch basins, street flooding and damaged street trees to 3-1-1 or visit 311 online
  • Reporting trees or branches on electrical wires or power outages to Alectra @alectranews or by visiting Alectra online

Who should I call?

  • Emergency assistance: 9-1-1
  • To report flooding: 3-1-1
  • Outside city limits: 905-615-4311

For more information on flood advisories and warnings in and around Mississauga, visit:

Basement flooding

If your home or basement has flooded, you should only contact 911 if you need assistance with rescue or evacuation.

A flooded basement is the property owner’s responsibility. You may wish to install a backflow preventer valve or a sump pump and generator or back-up power supply to help reduce damage if your basement does flood.

Maintaining proper drainage can also help ensure that water flows safely away from the walls of your home or other buildings on your property.

Blocked catch basins

Roadside catch basins need to be clear of obstructions like debris, leaves, and ice and snow to keep flowing freely. If you’re unable to safely clear the top of the catch basin grate with a shovel or broom and water is ponding, please report the catch basin’s location by calling 311 (905-615-4311 outside City limits).

You can also report a damaged or broken catch basin online.

Safety after a flood

Flooding in or around your home can cause safety issues, even after the floodwater is gone. Always keep children and pets away from flooded areas.

Get a professional opinion from your electricity company or an electrical contractor on whether water made contact with your electrical outlets. Do not enter a basement if the water level reaches electrical outlets.

If the water made contact with your outlets, you must contact Alectra to turn off your power before you begin removing water.

If your electricity company or contractor tells you that water has not made contact with your electrical outlets, you can begin removing the water.

Removing floodwater from your home

  • Do not move back into your home until flood cleanup is complete
  • Inspect flood damage in daylight. For darker areas like a basement, use battery powered flashlights.
  • If you detect gas, leave the building immediately. To have your gas shut off contact Enbridge.
  • Document any damage and call the Region of Peel and your insurance company
  • Make sure that water outside your home has receded before removing water from your home
  • Floodwater is typically contaminated. Mould can start growing as quickly as 48 hours after flooding.
  • Remove small amounts of water with pails or pumps and a wet-dry vacuum
  • Use caution when removing deep water from a basement. Remove a maximum of one third of the volume daily to avoid damaging the foundation of your house.
  • Open doors and windows and use fans if power is available to increase ventilation
  • Have any flooded gas, electrical appliances, heating equipment and ductwork checked by a qualified technician before use

Drinking water

Make sure that the water supply to your home has not been contaminated. If you’re not sure, boil drinking water for ten minutes or use purification tablets. If you have questions about your tap water contact the Region of Peel.

For more information on flooding, check the Residential Guide to Flood Prevention and Recovery.