178
WOCN11 CWTO 211435
YELLOW ADVISORY - FROST
FOR SOUTHERN ONTARIO
UPDATED BY ENVIRONMENT CANADA
AT 10:35 A.M. EDT THURSDAY 21 MAY 2026.
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YELLOW LEVEL ADVISORY - FROST - FOR:
=NEW= GATINEAU
=NEW= STIRLING - TWEED - SOUTH FRONTENAC
=NEW= BROCKVILLE - LEEDS AND GRENVILLE
=NEW= CITY OF OTTAWA
=NEW= PRESCOTT AND RUSSELL
=NEW= CORNWALL - MORRISBURG
=NEW= SMITHS FALLS - PERTH - EASTERN LANARK COUNTY
UXBRIDGE - BEAVERTON - NORTHERN DURHAM REGION
NEWMARKET - GEORGINA - NORTHERN YORK REGION
INNISFIL - NEW TECUMSETH - ANGUS
BARRIE - ORILLIA - MIDLAND
PETERBOROUGH - KAWARTHA LAKES
BANCROFT - BON ECHO PARK
PLEVNA - SHARBOT LAKE - WESTERN LANARK COUNTY
PARRY SOUND - MUSKOKA
HALIBURTON
RENFREW - PEMBROKE - BARRY'S BAY
ALGONQUIN
BURK'S FALLS - BAYFIELD INLET.
YELLOW LEVEL ADVISORY - FROST - ENDED FOR:
CALEDON
HURON - PERTH
WATERLOO - WELLINGTON
SHELBURNE - MANSFIELD - NORTHERN DUFFERIN COUNTY
ORANGEVILLE - GRAND VALLEY - SOUTHERN DUFFERIN COUNTY
OWEN SOUND - BLUE MOUNTAINS - NORTHERN GREY COUNTY
SAUGEEN SHORES - KINCARDINE - SOUTHERN BRUCE COUNTY
HANOVER - DUNDALK - SOUTHERN GREY COUNTY.
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IMPACT LEVEL: MODERATE
FORECAST CONFIDENCE: HIGH
==DISCUSSION==
FROST IS EXPECTED.
TEMPERATURES ARE EXPECTED TO FALL TO NEAR OR BELOW THE FREEZING MARK
TONIGHT INTO FRIDAY MORNING.
DAMAGE TO PLANTS, TREES, AND CROPS IS POSSIBLE. TAKE PREVENTATIVE
MEASURES TO PROTECT COLD-SENSITIVE PLANTS, TREES, AND CROPS. COVER
UP PLANTS, ESPECIALLY THOSE IN FROST-PRONE AREAS.
PLEASE CONTINUE TO MONITOR ALERTS AND FORECASTS ISSUED BY
ENVIRONMENT CANADA.
TO REPORT SEVERE WEATHER IN ONTARIO, SEND AN EMAIL TO
ONSTORM(AT)EC.GC.CA OR POST REPORTS ON X USING (HASH)ONSTORM. TO
REPORT SEVERE WEATHER IN GATINEAU, SEND AN EMAIL TO
ONSTORM(AT)EC.GC.CA OR POST REPORTS ON X USING (HASH)QCSTORM.
HTTP://WEATHER.GC.CA
END/OSPC
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