Notice

Update: Red-level severe thunderstorm watch issued for Mississauga

Residents are urged to prepare for potentially dangerous weather this afternoon and evening as Environment and Climate Change Canada issues a red-level Severe Thunderstorm Watch for Mississauga.

Emergency and public safety | September 2, 2026

heavy rain and tree in the parking lot

Environment and Climate Change Canada is warning that conditions are favourable for the development of severe thunderstorms capable of producing damaging winds, large hail, torrential rainfall and possible tornadoes.

The weather system is expected to develop this afternoon and continue into the evening bringing a risk of damaging wind gusts, hail, and heavy rain. Forecast confidence is high, and residents are encouraged to stay informed and be prepared to take shelter if conditions deteriorate.

Flooding and rising water levels possible

In addition to the severe thunderstorm watch, the Toronto and Region Conservation Authority (TRCA) and Credit Valley Conservation (CVC) have issued flood watch notices.

Heavy rainfall may cause water levels to rise quickly in rivers, streams, creeks and stormwater systems. Residents are encouraged to stay away from shorelines, waterways and other areas where conditions may become dangerous.

Reminders

Periods of heavier rain may lead to higher water levels across the city. For safety, residents are urged to:

  • Stay away from rivers, creeks, stormwater ponds and Lake Ontario.
  • Avoid low-lying areas that may flood quickly.
  • Watch for washouts near culverts and bridges.

Driving and outdoor safety

Wet weather can create hazardous conditions. Residents are reminded to:

  • Allow extra travel time.
  • Slow down and leave space between vehicles.
  • Drive according to road and weather conditions.
  • Avoid driving through flooded roads or pooled water.
  • Turn around if routes are not safe.

Pedestrians and cyclists should take extra care. Wet surfaces may be slippery and visibility may be reduced.

Fallen trees

To report a fallen or unsafe tree:

How residents can prepare

Small steps can help reduce risk:

  • Clear debris from storm drains near your home.
  • Check downspouts and direct water away from foundations.
  • Secure loose outdoor items.
  • Prepare an emergency kit in case of power outage.

City response

The City of Mississauga is monitoring weather conditions and local waterways.

City crews will monitor storm drains and respond to flooding or water pooling. Residents can report issues online or by calling 311 (or 905-615-4311 from outside city limits). The City’s Office of Emergency Management continues to work with conservation authority partners.

Understanding weather alert colours

Environment and Climate Change Canada uses colour-coded weather alerts to help people quickly understand the level of risk. The potential risk increases from yellow, to orange, to red.

Weather alert colour scale showing increasing risk from yellow to orange to red. Yellow alerts indicate hazardous weather with moderate, localized or short-term impacts. Orange alerts indicate severe weather likely to cause significant damage, disruption or health impacts. Red alerts indicate very dangerous and potentially life-threatening weather with extensive, widespread and prolonged impacts.

What is a flood watch or warning?

  • Flood outlook: Early notice of the potential for flooding.
  • Flood watch: Flooding may happen in certain areas.
  • Flood warning: Flooding is happening or will happen soon.

If a flood warning has been issued, act immediately to protect yourself from danger and your home from flood damage.

graphic explaining the difference in flood warnings

Stay informed

Weather conditions can change quickly. Residents are encouraged to:

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Media contact

City of Mississauga Media Relations
media@mississauga.ca
905-615-3200, ext. 5232
TTY: 905-896-5151
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