Red Warning: Severe Thunderstorm in Southwestern Ontario
This alert is no longer in effect.
ECCC issued it on May 19, 2026, 3 months ago. Warnings of this kind stay in effect for hours to a few days, so this page is a historical record of what was issued, not a current warning. For conditions where you are right now, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia).
Areazine synthesizes this ECCC weather alert directly from ECCC's official public data feed. See our methodology for full source attribution and refresh cadence.
Environment Canada has issued a red warning for a severe thunderstorm in Southwestern and the Golden Horseshoe area of Ontario, effective immediately.
Read this weather record in 30 seconds
- Record type
- Severe Thunderstorm Warning
- Affected area
- Southwestern Ontario
- Issued
- May 19, 2026
- Issuing authority
- ECCC
Storm notices can cover different combinations of wind, hail, lightning, and rainfall. Use the original notice for the hazards and boundaries attached to this specific record.
Record status: historical. It was issued 3 months ago; use the issuing agency's live warning service for current conditions in Southwestern Ontario.
Alert Details
Environment Canada has issued a red warning - severe thunderstorm - in effect. The alert was sent at 2026-05-19T23:00:22-00:00 with immediate urgency and extreme severity.
Affected Areas
The warning covers Southwestern and the Golden Horseshoe area Ontario, including the City of Hamilton, Niagara, Dunnville, Caledonia and Haldimand. Specific area described as Dunnville - Caledonia - Haldimand.
What You Should Do
Extra care and attention should be exercised in and around the affected localities.
Expected Conditions
Environment Canada meteorologists are tracking an extremely dangerous thunderstorm capable of producing destructive wind gusts and up to quarter size hail.
Timeline
The alert is effective from 2026-05-19T23:00:22-00:00 and expires at 2026-05-20T01:58:22-00:00.
Original source: ECCC Official Notice ↗
Related Weather Alerts
All Weather Alerts →Nationwide notices with similar length or severity timing 8
Two Areazine-derived peer sets for this ECCC weather alert: nearest notices by body length and by same severity near the same agency date. Peers come from other categories so they are not the same-feed Related list above.
Similar body length
Nearest notices by article body length (813 characters here).
Similar severity timing
Same severity (high) notices issued closest in time to May 19, 2026.
Frequently Asked Questions
Common questions about this ECCC weather alert.