Ontario’s First Confirmed Tornado of 2025: EF0 Touches Down Near Woodstock Last Week

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NOTE: YOU CAN CLICK ON THE MAP TO OPEN A ZOOMABLE IMAGE

Ontario’s tornado season has officially begun. The first confirmed tornado of 2025 touched down during the early morning hours of May 16th, just south of Lakeside, Ontario, northwest of Woodstock.

The tornado developed along the leading edge of a line of storms that had tracked into the province from Michigan.

While this EF0 tornado near Lakeside was the first confirmed in Ontario this year, it wasn’t the first in Canada.

According to the Northern Tornadoes Project, this brings Canada’s confirmed tornado count for 2025 to five.

The season began with an EF0 tornado in Alberta in early April, followed by an EF1 in Quebec later that month. Just one day before the Lakeside event, two EF0 tornadoes were confirmed in Manitoba on May 15th.

With peak season still ahead, this serves as a timely reminder that severe weather can happen quickly and under conditions that don’t always look extreme on the surface.

Even low-end risks deserve attention, especially when storms arrive at night, when people are less likely to be tuned in.

The Tornado: A Narrow but Confirmed Touchdown Near Lakeside

Survey map for the Lakeside EF0 tornado (source: Northern Tornadoes Project)

According to the Northern Tornadoes Project (NTP), the tornado developed just south of the village of Lakeside, approximately 25 km northwest of Woodstock. It touched down around 3:00 AM EDT, shortly after a squall line of thunderstorms entered the region from the west.

Drone photo of worst damage point featuring multiple snapped conifers (source: Northern Tornadoes Project)

Damage was limited to trees and a power pole, with no injuries reported. The tornado was assessed as an EF0, with estimated maximum wind speeds of 115 km/h. It travelled a distance of 3.6 km, with a maximum path width of 160 metres, moving generally from the west-southwest (255°).

Radar data shows possible rotation near lakeside (source: iw pro)

Radar imagery at the time showed a compact area of low-level rotation, but due to the storm’s embedded structure and the overnight timing, the event went unwitnessed until damage was reported later that day.

The NTP conducted both ground and drone surveys on May 20th to confirm the tornado’s track and intensity.

This information is sourced from the Northern Tornadoes Project’s full report, which can be found here.

Survey map showing the location of the EF0 downburst (black oval) and collected data (source: Northern Tornadoes Project)

In addition to the confirmed tornado near Lakeside, the Northern Tornadoes Project also verified a separate EF0 downburst near Chatham from the same storm system.

The downburst occurred around 2:15 AM EDT, roughly 45 minutes before the tornado, and caused significant damage to several barns, farm buildings, power poles, and trees.

While similar wind damage was reported across parts of Southwestern Ontario—from Windsor to Shrewsbury—only the enhanced damage south of Chatham was surveyed.

Wind speeds were estimated to have peaked at 130 km/h, placing the event at the high end of the EF0 scale. No injuries were reported.

Timeline: Forecast Leading Up to the Tornado

Forecast models began flagging the potential for severe storms several days in advance, particularly in Deep Southwestern Ontario, where the environment appeared favourable for severe weather.

Instant Weather and the U.S. Storm Prediction Center both noted the possibility of tornadoes — albeit marginal — due to the timing and nocturnal nature of the storms. This provided over 24 hours of advance notice about the potential for severe weather.

Despite the lower-end risk, one storm managed to spin up a brief EF0 tornado shortly after 3:00 AM on May 16th.

Instant Weather first highlighted the tornado potential on Wednesday afternoon, referencing the Storm Prediction Center’s forecast and the setup in Michigan and Southwestern Ontario:

The following morning, just under 24 hours before the confirmed tornado, Instant Weather once again flagged the risk.

This time, the post specifically mentioned that a 2% tornado risk extended into Sarnia, Chatham, Grand Bend, and as far northeast as London, placing the affected area firmly within the broader risk zone:

Later Thursday afternoon, a forecast was issued by Instant Weather calling for the potential of isolated tornadoes overnight. The forecast map outlined a marginal risk that included the area near Lakeside, where the tornado would eventually touch down:

Around 1:47 AM, just over an hour before the tornado touched down, Instant Weather sent out a custom notification for the London area, referencing minor rotation and clearly stating that “an isolated tornado cannot be ruled out”:

At 2:55 AM, Environment Canada issued a Severe Thunderstorm Warning, which included a note that severe thunderstorms can produce tornadoes. This came approximately five minutes before the tornado would touch down near Lakeside

Finally, live coverage was underway on Instant Weather’s YouTube channel during the time the tornado developed around 3:00 AM, as the storm moved through Oxford County.

Last Year Was a Record-Breaking Tornado Season in Canada, According to Northern Tornadoes Project

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The Northern Tornadoes Project (NTP), based out of Western University in London, Ontario, has just released their annual report on the 2024 tornado season. In it, the organization highlights that last year was a record-breaking year in terms of the length of the season.

Canada’s first tornado of the year was recorded in Malden Centre, Ontario on March 16th, coincidentally tying a tornado that hit Clifford, Ontario on March 16th, 2016 as the earliest recorded Ontario tornado. There were then a series of several late-season tornadoes that the NTP recorded: three individual twisters in New Brunswick on November 1st and the final tornado of the year near Fergus, Ontario on November 10th.

All told, this makes the 2024 tornado season 240 days long, over a span of nine different months. This is considerably longer than the typical season, which usually only has tornadoes in six separate months, from April to September. At this length, 2024 was the longest tornado season since at least 1980.

Another substantial finding in the report is that the 2024 tornado season was marked by the second-most tornadoes verified by the organization in a single season since their inception in 2017, with 129 tornadoes confirmed nationwide. A large spike in the total number came after the completion of the season, when the team could conduct further investigation and satellite review, which subsequently included an additional 16 tornadoes to the tally!

Most of the year’s tornadoes were rated as weak EF0s and EF1s, but the NTP did record 12 EF2 tornadoes. While this is double the amount from 2023, it is well below the 30+ recorded in both 2021 and 2022, both very active tornado seasons. Of these EF2 tornadoes, all but one (the Wolverton-Ayr tornado in Southern Ontario) occurred in forested areas of Northern Ontario and Quebec.

The Locations of all Tornadoes from 2024 and their corresponding EF-Scale Ratings, Courtesy of the Northern Tornadoes Project.

Geographically, Ontario was the province which was home to the most tornadoes this past season, with 50 tornadoes on land and 10 over water, which makes up almost half of all recorded tornadoes for the year. Out of the 50 tornadoes on land, 14 of them spawned during outbreaks on two individual days: June 29th had six and July 28th had eight. Quebec was the second-most active province, with 21 total tornadoes (four of which occurred over water), followed by Saskatchewan with 19.

At Instant Weather, we are a proud partner of the Northern Tornadoes Project. We developed our custom radar suite, Instant Weather Pro, in conjunction with the organization and the many weather reports from you, our community, help them in their mission.

For the upcoming 2025 season, the Northern Tornadoes Project team sounds excited to continue their work alongside the Northern Hail Project and the newly-founded Northern Mesonet Project. You can learn more about them at the Northern Tornadoes Project homepage and for more information regarding the report, you can find it here.