First published Oct 20, 2026, 5:54:15 PM UTC · Last updated Oct 20, 2026, 5:54:15 PM UTC

Snow, ice and extreme cold

Frost (advisory) - St. Catharines - Grimsby - Northern Niagara Region

Reported by Environment Canada Weather Alerts

Patchy frost is forecast tonight in the named area, mainly away from Lake Ontario, and the advisory recommends protecting cold-sensitive plants, trees, and crops. The alert is yellow with moderate impact and is listed to expire on October 21, 2026, at 09:19 UTC.

At a glance

Affected location: St. Catharines - Grimsby - Northern Niagara Region

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Why it matters

The advisory gives people in the affected area time to take the stated precautions for cold-sensitive vegetation.

Location

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Generated scores

Scores are based on the cited reporting and use a 1–10 scale. Read the methodology.

Confidence: 7/10How certain the assessment is based on the clarity and evidence in the cited reporting.
Geographic reach: 3/10How widely the event reaches, from a local area (1) to worldwide impact (10).
Global importance: 2/10The event's broader significance, from limited importance (1) to major global importance (10).
Impact magnitude: 2/10The scale or severity of the real-world impact, from minor (1) to extreme (10).
Urgency: 5/10How time-sensitive the event is, from low urgency (1) to immediate attention needed (10).

Primary official sources

Environment Canada Weather Alerts Frost (advisory) - St. Catharines - Grimsby - Northern Niagara Region

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