Severe weather hits Thunder Bay from every direction off Lake Superior. We log the storms and snow events that damage roofs so homeowners, reporters, and insurers have one sourced record to point to.
A running log of severe weather events that affect roofs across Thunder Bay and Northwestern Ontario. Each entry lists the date, the type of event, the communities in the path, measured wind, snow, or temperature where reported, and a link to the source. Some entries are Environment Canada warnings that describe the forecast hazard rather than a confirmed damage total. Entry-by-entry logging for the region begins in 2026; we add events as they are reported and sourced.
Affected areas Sioux Lookout, Eastern Lac Seul
Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts and large hail. (Text from the Environment Canada alert.)
Source: Environment and Climate Change Canada, public weather alertsAffected areas Fort Frances, Emo, Rainy River
Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts and heavy rain. Hazards: Torrential downpours with local rainfall totals near 50 mm. (Text from the Environment Canada alert.)
Source: Environment and Climate Change Canada, public weather alertsAffected areas Fort Frances, Emo, Rainy River
Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts, large hail and heavy rain. Hazards: Strong wind gusts of 90 km/h Quarter sized hail Torrential downpours When: This evening. (Text from the Environment Canada alert.)
Source: Environment and Climate Change Canada, public weather alertsAffected areas Fort Frances, Emo, Rainy River, Dryden, Vermilion Bay, Sioux Lookout, Eastern Lac Seul
Environment Canada placed the Fort Frances, Dryden, and Sioux Lookout forecast areas under a severe thunderstorm watch, with wind gusts approaching 90 km/h, loonie-size hail, and heavy downpours possible. A pre-dawn storm was already over Sioux Lookout, cutting visibility to 5 km in rain, when the watches were posted. Thunder Bay had no alerts in effect and recorded 5.7 mm of rain. No damage or outage reports followed. Loonie-size hail is right at the threshold where asphalt shingles start to bruise, so a watch like this is worth a quick look at the roof afterward even when nothing obvious came down.
Source: NetNewsLedgerAffected areas Agawa, Lake Superior Park
Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts, large hail and heavy rain. Hazards: Wind gusts up to 90 km/h. (Text from the Environment Canada alert.)
Source: Environment and Climate Change Canada, public weather alertsAffected areas Dryden, Vermilion Bay
Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts and large hail. Hazards: Wind gusts up to 90 km/h. (Text from the Environment Canada alert.)
Source: Environment and Climate Change Canada, public weather alertsAffected areas Dryden, Vermilion Bay
Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts and large hail. What: 90 km/h wind gusts Loonie to ping pong ball size hail Heavy downpours. (Text from the Environment Canada alert.)
Source: Environment and Climate Change Canada, public weather alertsAffected areas Atikokan, Shebandowan, Quetico Park
Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts, large hail and heavy rain. What: Quarter to ping pong ball sized hail. (Text from the Environment Canada alert.)
Source: Environment and Climate Change Canada, public weather alertsAffected areas Thunder Bay
A humid, unstable day brought gusty west winds, scattered showers, and a thunderstorm risk to Thunder Bay, with wildfire smoke in the area. Environment Canada's Thunder Bay CS station measured a 61 km/h peak gust and 9 mm of rain. Gusts in this range are below the damage threshold for a healthy roof, but they will peel back shingles that an earlier storm has already unsealed, which is how one windy afternoon turns old damage into an active leak.
Source: NetNewsLedgerAffected areas Thunder Bay
Thunder Bay sat under a severe thunderstorm watch and an air quality warning at the same time. Storms were capable of sudden heavy rainfall, frequent lightning, and strong gusts, while wildfire smoke cut visibility across the city. Residents were advised to secure loose outdoor objects.
Source: NetNewsLedgerAffected areas Thunder Bay, Cloud Bay-Dorion, Sleeping Giant Provincial Park
Environment Canada tracked a severe thunderstorm moving east at 50 km/h from the Boulevard Lake area, capable of 90 km/h gusts, quarter-size hail, and up to 50 mm of rain. Hail of that size can dent or crack shingles and vents even when no other damage is visible from the ground.
Source: Your ThunderBayAffected areas Kenora, Dryden, Bergland, Morson, Highway 17 corridor
A violent storm triggered red-coded tornado warnings for Kenora and Dryden, dropped nearly 10 cm of rain on Kenora, and flooded roads across the city. More than 4,200 Hydro One customers lost power along the Highway 17 corridor, and downed and damaged trees were reported in the Bergland area. The Northern Tornadoes Project sent a team to assess whether tornadoes touched down.
Source: NWONewsWatchAffected areas Thunder Bay
Thunder Bay was placed under a severe thunderstorm watch with conditions favourable for 90 km/h gusts and toonie-size hail. Local utility outages were possible if storms strengthened. Hail at this size is large enough to bruise asphalt shingles and dent metal roofing and flashing.
Source: NetNewsLedgerAct fast. Water that gets past damaged shingles can spread into the deck, attic, and ceilings within days, and snow load can stress a roof through a long winter. Take photos before any cleanup, then call for an emergency tarp and inspection. We can also walk you through the insurance claim process.
Event-by-event logging for Northwestern Ontario on this page begins in 2026. For longer-term context, insured damage from severe weather across Canada has climbed sharply, which is the trend driving higher claims and premiums everywhere, including the North.
Source: Insurance Bureau of Canada
Journalists, bloggers, and researchers are welcome to cite this page. Copy a ready-made citation below, or reach out for comment and the source data behind any figure.
Sleeping Giant Roofing. (2026). Northwestern Ontario Storm Damage Tracker 2026. Retrieved September 8, 2026, from https://sleepinggiantroofing.ca/northwestern-ontario-storm-damage-tracker/
"Northwestern Ontario Storm Damage Tracker 2026." Sleeping Giant Roofing, 8 September 2026, https://sleepinggiantroofing.ca/northwestern-ontario-storm-damage-tracker/.
Northwestern Ontario Storm Damage Tracker 2026. Sleeping Giant Roofing. https://sleepinggiantroofing.ca/northwestern-ontario-storm-damage-tracker/
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