Weather Desk Alert: Yellow Severe Thunderstorm Watch Issued for Thunder Bay
Thunder Bay – WEATHER DESK ALERT – Monday, June 29, 2026 — The City of Thunder Bay is under a Yellow Watch – Severe Thunderstorm, with Environment Canada reporting a high impact level and moderate forecast confidence. Conditions are favourable for severe thunderstorms this evening and overnight, with risks including damaging winds, large hail, heavy rain, and possible utility outages.
There are Tornado Alerts in effect in Dryden, Fort Frances, Emo, Rainy River and Atikokan.
Current Conditions
At 12:00 PM EDT at Thunder Bay Airport, conditions were cloudy with a temperature of 16.3°C. The dew point was 13.6°C, humidity was 84 percent, and winds were from the east at 19 km/h. Visibility was 24 km, and the barometric pressure was 101.1 kPa and falling, signalling an increasingly unsettled weather pattern.
Yellow Watch – Severe Thunderstorm
In Effect For
City of Thunder Bay
Main Threats
Environment Canada says storms this evening and overnight may be capable of producing:
Wind gusts of 90 to 110 km/h
Hail up to golf ball size
Torrential downpours of 50 to 75 mm
Possible utility outages
The main risks are expected to be wind and hail, though heavy rainfall could become a concern if storms repeatedly move over the same area.
Today’s Forecast
Thunder Bay will remain cloudy with a 30 percent chance of showers and a risk of a thunderstorm. The high will reach 19°C, with a UV index of 7, or high.
Tonight’s Forecast
Showers are expected to begin late this evening, with a risk of thunderstorms late this evening and overnight. Local rainfall amounts of 15 to 25 mm are forecast, though heavier totals may occur under stronger storms. The overnight low will be 17°C.
Tuesday Outlook
Tuesday will start wet, with showers ending in the morning, followed by a mix of sun and cloud. There is still a risk of a thunderstorm early in the morning. Temperatures will climb sharply, with a high of 29°C and a humidex of 34. The UV index will be 9, or very high.
Safety Guidance
If threatening weather approaches, move indoors and take shelter in a basement or interior room, away from windows. Secure loose outdoor items before storms arrive. Avoid driving through flooded roads, and remember: when thunder roars, go indoors.
Large hail can cause injury and property damage, while strong wind gusts can damage trees, buildings, and vehicles. Heavy rain may also reduce visibility and cause flash flooding.
Wardrobe and Preparedness Recommendations
For the rest of today, plan on rain gear, sturdy footwear, and a charged phone. Anyone with evening plans should monitor alerts closely and be prepared to move indoors quickly.
For Tuesday, switch to lightweight clothing as heat and humidity build, but keep an umbrella or rain jacket nearby for the morning showers.
Weather Trivia
Severe thunderstorm watches are issued when conditions are favourable for storms capable of producing damaging wind, hail, or heavy rain. A watch means “be ready,” while a warning means severe weather is occurring or imminent.
META Description: Thunder Bay weather alert for June 29, 2026: Yellow Severe Thunderstorm Watch in effect with possible 90–110 km/h winds, golf ball-sized hail, 50–75 mm rain, showers tonight, and humidex 34 Tuesday.
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