September 10-12, 2026: Northwestern Ontario Forecast — Sunshine Thursday, Summer Warmth Friday, Sharp Cooldown Saturday

Thunder Bay – WEATHER – Thursday, September 10, 2026 – Northwestern Ontario gets a welcome break from this week’s wind and rain Thursday, with sunshine and temperatures climbing into the low 20s.

Friday becomes even warmer, reaching 25°C to 26°C around Fort Frances, Dryden, Ignace and Armstrong, but clouds and showers begin returning later in the day.

Saturday brings the biggest change. Cooler air sweeps across the region, dropping daytime highs into the 13°C to 18°C range for most communities, along with scattered showers.

Today’s Weather Overview

Early Thursday has a definite fall feel in parts of Northwestern Ontario.

At 5:00 a.m. CDT, Dryden was mainly clear and 8.1°C, with humidity at 93 percent and pressure at 101.5 kPa. Red Lake was clear and only 4.8°C, with humidity at 97 percent. Sioux Lookout reported fog patches and 2.1°C, with humidity at 100 percent.

Farther east, Armstrong was cloudy and 9.5°C at 6:00 a.m. EDT, with northwest winds at 11 km/h gusting to 35 and pressure at 101.3 kPa. Pickle Lake was cloudy and 7.9°C, with northwest winds at 8 km/h.

Community Forecasts

Kenora

Thursday: Sunny after any early fog dissipates. Southwest winds increase to 20 km/h gusting to 40. High near 22°C, with humidex 25. Clear tonight.

Friday: Mix of sun and cloud with a 30 percent chance of showers. High 23°C.

Saturday: Much cooler with a mix of sun and cloud and a 30 percent chance of showers. High only 15°C.

Fort Frances

Thursday: Mainly sunny and warm. High 24°C, humidex 26.

Friday: Mix of sun and cloud with a 30 percent chance of showers. High 25°C.

Saturday: Cooler with a mix of sun and cloud and a 30 percent chance of showers. High 17°C.

Dryden and Vermilion Bay

Thursday: Mainly sunny after morning fog dissipates. Southwest winds increase to 20 km/h gusting to 40. High 21°C.

Friday: Increasing cloudiness with a 40 percent chance of late-afternoon showers and a risk of a thunderstorm. High 25°C, humidex 30.

Saturday: Mix of sun and cloud with a 30 percent chance of showers. High 16°C.

Ignace

Thursday: Mix of sun and cloud after morning fog clears. Southwest wind near 20 km/h. High 21°C.

Friday: Increasing cloud with a 40 percent chance of late-day showers and a thunderstorm risk. South winds gust to 40 km/h early. High 26°C, humidex 31.

Saturday: Much cooler with a mix of sun and cloud and a 30 percent chance of showers. High 16°C.

Red Lake

Thursday: Mainly sunny. South winds increase to 20 km/h gusting to 40. High 22°C.

Friday: Mainly cloudy with a 30 percent chance of late-afternoon showers. High 22°C.

Saturday: Cloudy and sharply cooler with a 60 percent chance of showers. High only 13°C.

Sioux Lookout

Thursday: Morning fog clears, followed by sun and cloud. Southwest winds increase to 20 km/h gusting to 40. High 21°C.

Friday: Mainly sunny early, then increasing cloud with a 30 percent chance of late-afternoon showers. High 24°C, humidex 28.

Saturday: Mix of sun and cloud with a 60 percent chance of showers. High only 14°C.

Armstrong

Thursday: Mainly cloudy early with a 30 percent shower chance, then clearing this afternoon. West wind near 20 km/h. High 20°C.

Friday: Sunny early, becoming a mix of sun and cloud with a 30 percent chance of late-afternoon showers. High 25°C, humidex 29.

Saturday: Mix of sun and cloud with a 40 percent chance of showers. High 18°C.

Pickle Lake

Thursday: Mix of sun and cloud with a 30 percent chance of an early shower. High 20°C.

Friday: Mainly cloudy with a 30 percent chance of late-afternoon showers. Southwest winds around 30 km/h early. High 23°C.

Saturday: Cloudy with a 40 percent chance of showers and a high of only 13°C.

Regional Three-Day Trend

Thursday is the best overall weather day, with temperatures generally between 20°C and 24°C and plenty of sunshine once morning fog clears.

Friday is the warmest day. Ignace reaches 26°C, Fort Frances, Dryden and Armstrong reach 25°C, and Sioux Lookout reaches 24°C. Shower chances increase later in the afternoon, with thunderstorms possible around Dryden, Vermilion Bay and Ignace.

Saturday brings a sharp temperature drop, especially across the north. Red Lake and Pickle Lake reach only 13°C, Sioux Lookout 14°C and Kenora 15°C. Showers remain possible across the entire region.

Highway and Travel Outlook

Thursday offers the strongest highway weather of the three days after morning fog dissipates.

Drivers should watch for stronger southwest crosswinds around Kenora, Dryden, Red Lake and Sioux Lookout, where gusts can reach around 40 km/h.

Friday afternoon and evening become more weather-sensitive as showers develop, with thunderstorms possible in parts of the Highway 17 corridor.

Saturday brings cooler temperatures and scattered showers, which may produce brief reductions in visibility on Highways 17, 71, 72, 105 and 599.

Check 511.on.ca before longer trips for current road conditions, construction, closures and incidents.

Boating and Outdoor Outlook

Thursday provides the best overall outdoor window, although southwest winds may create some chop on exposed water.

Friday will be very warm for September, but boaters should keep an eye on developing afternoon showers and thunderstorms.

Saturday is significantly cooler and more unsettled, particularly around Red Lake, Lac Seul and Pickle Lake.

Anyone heading onto Lake of the Woods, Rainy Lake, Lac Seul or Wabigoon Lake should check the latest local wind forecast before departure.

Wardrobe Recommendations

Thursday and Friday favour lighter daytime clothing, although mornings remain cool.

Friday may feel almost midsummer-like around Fort Frances, Dryden, Ignace and Armstrong.

Keep a rain shell nearby Friday afternoon.

Saturday requires a return to fall layers, especially across Red Lake, Sioux Lookout and Pickle Lake, where highs struggle through the low-to-mid teens.

Weather Trivia

Ignace highlights just how quickly September weather can change in Northwestern Ontario.

Friday’s forecast high is 26°C, with humidex 31. By Saturday, the high falls to only 16°C — a ten-degree drop in about 24 hours.

That kind of rapid change is common during September as warm southern air is replaced by cooler air moving southeast across the Canadian Shield.

Source: Environment and Climate Change Canada forecasts and observations available early Thursday, September 10, 2026.

Overview

Northwestern Ontario weather for September 10-12, 2026: Sunshine and highs in the low 20s Thursday give way to summer-like warmth Friday before a sharp cooldown and scattered showers Saturday across Kenora, Dryden, Fort Frances, Red Lake, Sioux Lookout, Armstrong and Pickle Lake.