November 10, 2024
EF0Elora & Fergus
Wellington County
Winds: 115 km/h • Track: 4.2 km
Late-season cold frontal supercell produced a narrow track through open agricultural fields, peeling roof flashing and snapping tree limbs.
Ontario ECCC Severe Weather Stream
Ontario Tornado Today: Live Tracker
Track Ontario tornado today with live monitoring of real-time Environment and Climate Change Canada (ECCC) warnings, watches, and Doppler radar imagery across Ontario.
Population:15.8 MillionAnnual Frequency:18 tornadoes / yrPeak Risk Window:June to July
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Live ECCC Alert Bulletin
Ontario Active Severe Weather & Tornado Alerts
Streaming real-time official bulletins from Environment and Climate Change Canada (ECCC) for Ontario.
Active Canadian Bulletins:0
No Active Tornado Warnings in Ontario
Environment and Climate Change Canada (ECCC) Doppler radar is active across all 33 radar sites. Zero active tornadic rotations detected at this time.
Provincial Climatology • Environment Canada & NTP
Ontario Tornado Statistics, Frequency & Risk Trends
Historical severe convective data compiled from Environment and Climate Change Canada (ECCC) archives, the Northern Tornadoes Project (NTP) at Western University, and forensic post-storm ground surveys across Ontario.
884Confirmed Touchdowns
18 / yrAnnual Average
June to JulyPeak Seasonal Window
HighProvincial Threat Tier
Barrie F4Strongest Verified
66.7%June & July Activity
Seasonality & Monthly Trends
Monthly Ontario Tornado Frequency Distribution
Severe convective weather in Ontario follows a concentrated summertime bell curve. The sharp influx of warm, moist surface air combined with upper-level jet dynamics drives peak tornadogenesis during June and July, accounting for 66.7% of all documented touchdowns.
0.1%Jan
0.1%Feb
0.3%Mar
2.5%Apr
9.8%May
28.5%Jun
38.2%Jul
14.1%Aug
5.3%Sep
1%Oct
0.1%Nov
0%Dec
Winter Minimum (< 0.5%)Peak Climatological Window: June to July (66.7%)Autumn Falloff (< 2%)
Severity Spectrum
Ontario Tornado Severity Breakdown (EF-Scale)
Historical distribution of confirmed tornadoes across Ontario categorized by the Enhanced Fujita Scale. While weak EF0 and EF1 funnels comprise the majority of touchdowns, violent twisters (EF2+) represent the greatest threat to life and infrastructure.
EF0(105 to 137 km/h)
479 documented eventsProvincial Share54.2%
Light damage: Peels roof flashing, snaps tree branches, topples signboards and chimneys.
EF1(138 to 177 km/h)
284 documented eventsProvincial Share32.1%
Moderate damage: Strips roof decking, overturns unanchored trailers, snaps mature tree trunks.
EF2(178 to 217 km/h)
93 documented eventsProvincial Share10.5%
Considerable damage: Roofs torn off well-built homes, exterior walls breached, large trees uprooted.
EF3(218 to 266 km/h)
23 documented eventsProvincial Share2.6%
Severe damage: Entire stories of houses collapsed, heavy commercial transport tossed, high missile hazard.
EF4(267 to 322 km/h)
5 documented eventsProvincial Share0.6%
Devastating damage: Well-constructed framed homes leveled, cars lofted hundreds of metres.
EF5(> 322 km/h)
0 documented eventsProvincial Share0%
Incredible damage: None recorded in Ontario (only one in Canadian history was in Manitoba).
Geographic Vulnerability
High-Risk Counties & Municipalities in Ontario
Historical touchdown density highlights distinct regional corridors where terrain, moisture convergence, and boundary collisions repeatedly foster severe convective supercells.
Simcoe County (Barrie)High Risk
48 Touchdowns
1985 Barrie F4 outbreak & 2021 Prince William Way EF2
Middlesex County (London)High Risk
39 Touchdowns
Lake Huron/Erie lake-breeze front intersection supercells
Essex County (Windsor)High Risk
36 Touchdowns
1946 Windsor F4 (17 deaths) & multi-vortex tornado swarms
Ottawa-Carleton (Ottawa)High Risk
31 Touchdowns
2018 Dunrobin EF3 & 2019 Arlington Woods EF1 supercells
Oxford County (Woodstock)High Risk
28 Touchdowns
1979 Woodstock F4 outbreak & rural farmstead impacts
Wellington County (Elora/Guelph)Moderate Risk
24 Touchdowns
2024 Elora EF0 touchdown & localized squall line rotation
Waterloo Region (Ayr/Kitchener)Moderate Risk
22 Touchdowns
2024 Ayr EF1 twister & severe Grand River Valley cells
Niagara Region (Niagara Falls)Moderate Risk
19 Touchdowns
2024 Chippawa EF0 Lake Erie waterspout landfall
Documented Forensic Archive • Northern Tornadoes Project & ECCC
Historical Ontario Tornado Touchdown Log & Timeline
Showing 12 verified eventsChronological record of verified tornadoes in Ontario investigated through post-event ground surveys, aerial drone imagery, Doppler radar velocity couplets, and civil engineering damage indicators.
September 17, 2024
EF1Morison Lake
Muskoka District
Winds: 145 km/h • Track: 6.1 km
Cottage country supercell tracked through mature hardwood forest, snapping pine trees and damaging lakeside boathouses.
September 17, 2024
EF0Film Lake
Muskoka District
Winds: 120 km/h • Track: 3.4 km
Twin vortex spawned from the Muskoka squall line, uprooting shallow-rooted birch trees along remote terrain.
September 9, 2024
EF0Niagara Falls / Chippawa
Niagara Regional Municipality
Winds: 125 km/h • Track: 2.1 km
Lake Erie waterspout came ashore near Chippawa, downing overhead power lines and scattering lawn furniture.
August 31, 2024
EF1Oliver Lake / South Gillies
Thunder Bay District
Winds: 155 km/h • Track: 8.5 km
Northwestern Ontario low-topped supercell flattened a swath of mature boreal spruce forest; verified by NTP drone survey.
August 24, 2024
EF1Ayr & North Dumfries
Waterloo Regional Municipality
Winds: 165 km/h • Track: 9.2 km
Embedded tornadic cell within a high-precipitation supercell tore roof shingles off buildings and damaged a Home Hardware store.
July 15, 2021
EF2Barrie / Innisfil
Simcoe County
Winds: 210 km/h • Track: 12.5 km
High-end EF2 wedge tore through Prince William Way subdivision, ripping roofs off well-built residences and injuring 11 people.
September 21, 2018
EF3Dunrobin & Ottawa Valley
Ottawa-Carleton
Winds: 265 km/h • Track: 38.8 km
Long-track intense tornado leveled 60+ homes in rural Dunrobin before crossing the Ottawa River into Gatineau, injuring 30 people.
August 21, 2011
F3Goderich
Huron County
Winds: 280 km/h • Track: 20.0 km
Violent supercell spawned over Lake Huron and struck downtown Goderich, destroying historic Victorian buildings and causing 1 fatality.
May 31, 1985
F4Barrie & Simcoe County
Simcoe County
Winds: 400 km/h • Track: 10.0 km
Deadliest Ontario twister in modern history. An F4 funnel ripped through southern Barrie with 400 km/h winds, killing 8 and destroying 600 homes.
August 7, 1979
F4Woodstock
Oxford County
Winds: 380 km/h • Track: 32.0 km
Violent late-afternoon supercell produced two devastating F4 funnels near Woodstock, killing 3 and causing over $100M in damages.
June 17, 1946
F4Windsor & LaSalle
Essex County
Winds: 410 km/h • Track: 60.0 km
Deadliest tornado in Ontario history. Crossed the Detroit River into Windsor, leveling industrial plants and homes, killing 17 people.
Meteorological Science • ON
Great Lakes Boundary Collisions & Thermal Vorticity
Southern Ontario represents Canada's most vulnerable corridor for severe tornadic supercells due to its unique position between Lake Huron, Lake Erie, and Lake Ontario. During early summer, intense surface insolation heats the inland landmass, drawing cooler, moisture-laden marine air inland. The resulting lake-breeze boundaries create sharp micro-fronts with intense horizontal shear. When approaching cold fronts or squall lines intercept these boundaries, horizontal vorticity is tilted upward, producing rapid tornadogenesis.
Primary Severe Convective Triggers in Ontario:
Lake Huron and Lake Erie lake-breeze front convergence lines
Southwesterly warm-sector low-level jets channeling Gulf moisture
Upper-level jet streak divergence over the Lower Great Lakes basin
Pre-frontal mesoscale convective systems crossing from Michigan and Ohio
Radar Surveillance Network
Environment Canada S-Band Doppler Radars Covering Ontario
High-resolution dual-polarization S-band Doppler radar stations monitoring tornadic rotation across Ontario:
CWKR
King City Radar
York Region (Greater Toronto & Simcoe)
CWSO
Exeter Radar
Huron County (Southwestern Ontario)
CWFT
Frankford Radar
Hastings County (Eastern Ontario)
CWBI
Britt Radar
Parry Sound District (Georgian Bay)
Emergency Preparedness
Ontario Sheltering Guidelines & Alert Ready Protocols
Single-Family Home
Move immediately to the basement. Take shelter under a sturdy workbench or beneath the stairs. Stay away from windows.
High-Rise Apartment
Do not use elevators. Move to an interior central hallway or stairwell on the lowest available floor away from exterior glass.
Cottage or Mobile Home
Evacuate immediately. Mobile homes and lakeside cabins lack below-ground foundation anchoring. Seek shelter in a sturdy community building.
Explore Nationwide Canadian Severe Weather Intelligence
Track Canada TornadoCompare Ontario's tornadic statistics with all 13 provinces and territories on our national hub.
Frequently Asked Questions
Ontario Tornado Tracker FAQ
Official answers regarding Ontario's tornadic risks, peak season, warning systems, and shelter guidance.
You can verify active tornadoes in real time using the live Environment and Climate Change Canada (ECCC) radar and alert feed at the top of this page. When a severe convective storm produces confirmed rotation or a touchdown occurs, ECCC immediately issues a red Tornado Warning and emergency Alert Ready broadcasts across impacted Ontario municipalities.
Canadian Severe Weather Corridors
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Track real-time Environment Canada radar and active tornado alerts across neighboring provinces.
Avg 16/yr • High Risk
Avg 20/yr • High Risk
Avg 11/yr • High Risk
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