Thunder Bay – Weather – The weather outlook across Northwestern Ontario is starting with a calm solid start.

Don’t let that lull you into weather calm however.

While Northwest Ontario begins the week with calm, mild, and sunny conditions, that will change quickly.

A passing low-pressure system will bring showers, the risk of thunderstorms, gusty winds, and even local smoke in some areas by this afternoon.

From Kenora to Fort Frances and up to Sioux Lookout, residents should be prepared for a swift shift from summer calm to active weather.

Today’s Weather Overview

Current Conditions (6:00 AM CDT)

Kenora – Airport Observation

• Temp: 15.2°C | Humidity: 93% | Wind: SW 12 km/h

• Sky: Mainly clear | Pressure: 101.2 kPa, falling

• Visibility: 24 km

Dryden – Airport Observation

• Temp: 15.4°C | Humidity: 99% | Wind: S 9 km/h

• Sky: Mainly sunny | Pressure: 101.2 kPa

• Visibility: 16 km

Sioux Lookout – Airport Observation (based on regional forecast patterns)

• Temp: Around 15°C | Humidity: Near 100% | Wind: Light southerly

• Sky: Mainly clear with early fog patches

Fort Frances – Airport Observation (based on regional forecast patterns)

• Temp: Around 16°C | Humidity: High | Wind: Light SW

• Sky: Mostly sunny

Regional Daytime Forecast

• Morning: Mainly sunny, fog patches dissipating.

• Late Morning to Afternoon: Increasing cloud, showers developing with a risk of thunderstorms. Local smoke possible in Kenora, Sioux Lookout, and surrounding areas.

• Rainfall: 10–20 mm possible in heavier downpours.

• Wind: Becoming southwest 30 km/h gusting to 50 km/h; stronger gusts in storms.

• Highs: Around 23°C in Kenora, Dryden, Sioux Lookout; near 25°C in Fort Frances.

• Humidex: 28

• UV Index: 7 – High

Tonight

• Conditions: Showers and possible thunderstorms.

• Wind: SW 40 km/h gusting to 60, becoming W 20 km/h gusting to 40 after midnight.

• Low: 16°C across most of the region.

Tomorrow’s Forecast – Tuesday, August 12, 2025

• Morning: Showers ending, remaining cloudy with a 40% chance of lingering showers. Risk of a morning thunderstorm in some locations.

• Local Smoke: Possible in Kenora, Sioux Lookout, and Fort Frances.

• Wind: NW 20 km/h gusting to 40.

• High: Around 19°C for Kenora, Dryden, and Sioux Lookout; 21°C in Fort Frances.

• UV Index: 4 – Moderate

Night: Cloudy periods, 30% chance of showers, low 12°C.

Wednesday, August 13, 2025

• Daytime: Overcast skies, highs near 20°C.

• Night: Clear, lows around 13°C.

Wardrobe Recommendations

• Today: Light summer clothing for the morning warmth, but carry a waterproof jacket or umbrella for afternoon showers. Sunglasses and sunscreen recommended before clouds roll in.

• Tonight: Rain gear for evening showers and gusty winds.

• Tuesday: Light layers with a windbreaker for cooler, breezier conditions.

Weather Trivia

Fort Frances holds the record for Ontario’s highest recorded temperature at 42.2°C on July 13, 1936. While today’s highs are far cooler, the rapid change from calm skies to storms is a reminder of how dynamic Northwest Ontario weather can be in summer.

Drive Safe!

Drive to arrive alive. Our regional highways can be a real white knuckle roller coaster.