Thunderstorms and heavy rain expected in Mississauga today

Thunderstorms and heavy rain expected in Mississauga today

Residents are urged to prepare for rainy conditions and strong winds as storm conditions develop across southern Ontario.

July 21, 2026

view of rain in a car with windshield wipers moving

Storm activity may develop through the morning and continue into the afternoon, with the greatest risk for impacts expected later in the day.

The Toronto and Region Conservation Authority (TRCA) and Credit Valley Conservation have issued a Flood Outlook Statement, and Environment and Climate Change Canada (ECCC) has issued a Yellow Level Severe Thunderstorm Watch for the area.

Residents should be prepared for rapidly changing weather conditions, including heavy rain, strong winds and localized flooding. The timing and severity of these storms remain uncertain and may change as weather conditions develop.

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:

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

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 in collaboration with Environment & Climate Change Canada and our conservation authority partners.

City crews are monitoring storm drains and responding as needed. Residents can report issues online or by calling 311 (or 905-615-4311 from outside city limits).

Stay informed

Weather conditions can change quickly. Residents are encouraged to:

For flooding concerns, call 311.