Frost advisory this weekend for parts of Northern Ontario
A frost advisory has been issued by Environment Canada for several northern regions of Ontario, with overnight temperatures expected to dip near 0°C (32°F) between Saturday night and Sunday morning.
According to Environment Canada, clear skies and light winds will create ideal conditions for radiational cooling, potentially causing frost in low-lying and exposed areas. Although southern Ontario communities—such as Mississauga, Brampton, Halton, Hamilton, and Durham—are not currently affected, local microclimates could still lead to unexpected changes.
Who is affected
The advisory covers remote and northern Ontario zones, particularly where agricultural and natural vegetation are at greater risk due to their latitude and terrain. Areas under frost warning include:
Agawa – Lake Superior Park, Armstrong – Auden – Wabakimi, Beardmore – Jellicoe – Macdiarmid, Chapleau – Missinaibi Lake, Fraserdale – Pledger Lake, Geraldton – Longlac – Caramat, Kapuskasing – Hearst – Smooth Rock Falls, Manitouwadge – Hornepayne, Marathon – Schreiber, Nakina – Aroland – Pagwa, Wawa – Pukaskwa Park, and White River – Dubreuilville.
What it means for residents
Gardeners, farmers, and those with outdoor-sensitive plants are encouraged to take preventive action, such as covering delicate vegetation or bringing potted plants indoors to avoid cold damage. Even minimal frost formation can impact plant growth or destroy young crops, especially in areas with limited frost resilience.
This advisory is part of Environment Canada’s ongoing alerts aimed at minimizing frost-related losses during early June cold snaps, which can still affect higher latitude and elevated terrain in Ontario’s interior.
