# Canadian flooding and outages July 2026

> Live situation record from CLSTR: https://clstr.news/situations/montreal-flooding-and-power-outages
> Updated: 2026-07-02T23:29:14.000Z. Sources: 26. Developments: 5.

In late June 2026 a severe storm over southern Quebec dumped 100–150 mm of rain, causing flash flooding in the Greater Montreal area. Street water surged in Pierrefonds, Highway 40 was closed at exits 52 and 55 and Montréal‑Trudeau Airport faced disruptions. Over 18,000 customers lost power, and a state of emergency was declared in Saint‑Constant. By June 22, additional road closures on Route 307, Chemin de la Montagne, Chemin de l’Église and further sections of Highway 40 remained in effect, while Hydro‑Québec still reported roughly 7,500 customers without electricity. Insurers warned that most standard Canadian home policies exclude over‑land flood or sewer‑backup damage, noting that flood losses in Quebec and Ontario contributed about $3.7 billion to the $8.6 billion in catastrophe claims for 2024. A week later, a powerful thunderstorm system moved north into southern and western Manitoba. Boissevain recorded a record 152 mm of rain, and five other communities each received more than 100 mm. Wind gusts exceeded 106 km/h in Morden. The storm caused street flooding, basement inundations, sewer backups and knocked out power for over 14,000 Manitoba Hydro customers. Municipalities declared states of emergency, closed roads, urged water conservation and cancelled Canada Day celebrations. On Canada Day (July 1), another severe thunderstorm complex struck Ontario and Quebec, setting new rainfall records such as 118 mm in Ottawa. The deluge flooded basements, knocked down trees and forced the cancellation of national fireworks displays in Ottawa and Toronto. Power outages affected roughly 168,000 Hydro One customers in Ontario and more than 9,000 Hydro‑Québec customers, leaving thousands without electricity for several days. Environment Canada issued orange‑level heat warnings as temperatures rose into the mid‑30s °C with humidex values near 45, prompting public‑health advisories on hydration and cooling centres.

## Timeline

### 2026-07-02: Severe thunderstorms knock out power to hundreds of thousands in Ontario and Quebec

Severe July storms in Ontario and Quebec caused record power outages for over 350,000 customers, widespread flooding in Ottawa‑Gatineau, and prompted massive utility response.

5 sources. https://clstr.news/cluster/severe-thunderstorms-knock-out-power-to-hundreds-of-thousands-in-ontario-and-quebec

### 2026-06-30: Ontario and Quebec power outages after Canada Day storms

Canada Day thunderstorms caused record rain, floods, and widespread power outages for hundreds of thousands in Ontario and Quebec, prompting event cancellations and heat‑wave alerts.

17 sources. https://clstr.news/cluster/heat-wave-and-power-outages-disrupt-ontario-and-canada-day-events

### 2026-06-30: Manitoba Storm Triggers Widespread Flooding, Power Outages and Emergency Declarations

A severe Manitoba thunderstorm dumped up to 152 mm of rain, caused flooding, sewer backups, power outages for 14,000+ customers and led to emergency declarations in Boissevain and Deloraine.

2 sources. https://clstr.news/cluster/manitoba-storm-triggers-widespread-flooding-power-outages-and-emergency-declarations

### 2026-06-21: Southern Quebec Floods Disrupt Roads, Power and Prompt Insurance Alerts

Heavy rain caused flash floods in southern Quebec, closing roads, cutting power and prompting state emergencies; insurers warn many Canadians lack flood coverage as claims rise.

4 sources. https://clstr.news/cluster/severe-rain-floods-roads-and-cuts-power-in-quebecs-greater-montreal-area

### 2026-06-20: Heavy rains trigger extensive flooding in Montreal, power outages and highway closures

Intense rain on June 20 caused severe flooding in Montreal's West Island, power outages for over 18,000 customers, Highway 40 closures and temporary airport disruptions, with no injuries reported.

2 sources. https://clstr.news/cluster/heavy-rains-trigger-extensive-flooding-in-montreal-power-outages-and-highway-closures

---
Cite as: Canadian flooding and outages July 2026. CLSTR, https://clstr.news/situations/montreal-flooding-and-power-outages