September 7-9, 2026: Northwestern Ontario Forecast — Heavy Rain Tonight, Windy Tuesday, Sharp Cooldown Wednesday
Thunder Bay – Weather Desk – WEATHER – Monday, September 7, 2026 – Labour Day is shaping up as a wet and increasingly unsettled day across Northwestern Ontario, with a stronger round of rain arriving tonight before gusty winds sweep across the region Tuesday.
Environment Canada is forecasting 30 to 40 millimetres of rain tonight in several communities, including Kenora, Fort Frances, Dryden, Red Lake and Sioux Lookout. Thunderstorms are also possible. Tuesday then turns windy, particularly across the west, where gusts may reach 50 to 60 km/h.
The most dramatic change arrives Wednesday as cooler air pours into Northwestern Ontario. Communities that climb into the mid-to-upper 20s Tuesday will struggle through the mid-teens Wednesday.
Monday, September 7
Kenora
Kenora will be cloudy with a 40 percent chance of showers this morning and early this afternoon.
Southeast winds develop near 20 km/h this afternoon. The high reaches 21°C, with a humidex of 29.
Conditions deteriorate significantly tonight. Showers will be heavy at times, with a risk of thunderstorms and rainfall amounts of 30 to 40 mm.
Southeast winds strengthen to 30 km/h gusting to 50 km/h, while temperatures remain unusually mild with a low of 19°C.
Fort Frances
Fort Frances remains cloudy today with a 40 percent chance of showers through early afternoon.
South winds develop near 20 km/h, with a high of 24°C and humidex of 31.
Tonight brings heavy showers and a thunderstorm risk, with another 30 to 40 mm possible. South winds reach 20 km/h gusting to 40, and the low is 19°C.
Vermilion Bay and Dryden
Dryden and Vermilion Bay will be cloudy with a 60 percent chance of showers this morning and early afternoon.
The high reaches 21°C, with a humidex of 28.
Tonight becomes much wetter. Showers will be heavy at times, thunderstorms are possible, and rainfall amounts of 30 to 40 mm are forecast.
South winds increase to 30 km/h gusting to 50 km/h late this evening. The overnight low is 18°C.
Ignace
Ignace will see showers ending this afternoon, followed by cloudy skies.
Local rainfall amounts of 10 to 20 mm are possible today. South winds develop near 20 km/h, with a high of 21°C and humidex of 28.
More showers begin this evening, with thunderstorms possible late tonight. Another 20 to 30 mm is expected.
South winds increase to 30 km/h gusting to 50 km/h, with a low of 17°C.
Red Lake
Red Lake will be cloudy with a 40 percent chance of showers this morning and early afternoon.
East winds increase to 20 km/h gusting to 40 km/h, with a high of 19°C.
Tonight brings heavy showers, a thunderstorm risk and 30 to 40 mm of rain.
Southeast winds reach 20 km/h gusting to 40. The overnight low is 17°C.
Sioux Lookout
Sioux Lookout remains cloudy with a 60 percent chance of showers this morning and early afternoon.
East winds develop near 20 km/h late this afternoon. The high reaches 19°C.
Tonight turns stormier. Showers will be heavy at times, with thunderstorms possible and 30 to 40 mm of rain expected.
East winds gust to 40 km/h before becoming south at 30 km/h gusting to 50 km/h after midnight. The low is 17°C.
Armstrong
Armstrong faces one of the wettest daytime forecasts.
Showers are expected with a risk of thunderstorms, producing 20 to 30 mm of rain.
East winds develop near 20 km/h gusting to 40 km/h, and the high reaches only 15°C.
Tonight stays unsettled with additional showers developing overnight and another thunderstorm risk. The low is 14°C.
Pickle Lake
Pickle Lake remains cool and unsettled Monday, with a 60 percent chance of showers and a high near 16°C.
Rain becomes more persistent tonight, with temperatures near 12°C.
Tuesday, September 8 — Warmer but Windy
Tuesday brings a strange combination of warmer temperatures, lingering heavy rain and strong winds.
Kenora
Heavy showers end during the morning, followed by a mix of sun and cloud.
A thunderstorm remains possible early.
Southwest winds increase from 20 km/h gusting to 40 to 40 km/h gusting to 60 km/h during the afternoon.
The high reaches 23°C, with a humidex of 28.
Fort Frances
Heavy showers end during the morning, followed by clearing.
There is a risk of an early thunderstorm.
Southwest winds reach 20 km/h gusting to 40 km/h.
Fort Frances becomes one of the warmest communities in the region at 27°C, with a humidex of 32.
Dryden and Vermilion Bay
Heavy showers end during the morning before skies clear.
Thunderstorms remain possible early.
Southwest winds reach 30 km/h gusting to 50 km/h, with a high of 25°C and humidex near 30.
Ignace
Showers end during the morning, followed by clearing.
Southwest winds blow at 30 km/h gusting to 50 km/h, while temperatures rise to 25°C.
The humidex reaches 32.
Red Lake
Heavy showers end in the morning, followed by a mix of sun and cloud.
South winds gust to 50 km/h before becoming southwest at 40 km/h gusting to 60 km/h during the afternoon.
The high reaches 23°C.
Sioux Lookout
Heavy showers end in the morning before skies clear.
South winds reach 30 km/h gusting to 50 km/h, turning west at similar speeds late in the afternoon.
The high climbs to 24°C, with a humidex of 30.
Armstrong
Showers continue through much of Tuesday before ending late in the afternoon.
Thunderstorms remain possible.
South winds reach 20 km/h gusting to 40 km/h, and the high rises to 20°C.
Pickle Lake
Tuesday remains wet around Pickle Lake, with rain forecast and a high near 23°C.
Showers remain possible Tuesday night.
Wednesday, September 9 — Much Cooler
Wednesday is when the early-autumn air really takes over.
Kenora: Cloudy with a 60 percent chance of showers, high 16°C, overnight low near 10°C.
Fort Frances: Cloudy with a 60 percent chance of showers, high 17°C, nighttime low near 8°C.
Dryden and Vermilion Bay: Cloudy with a 60 percent shower chance and a high near 15°C to 17°C, followed by lows around 8°C to 9°C.
Ignace: Cloudy with a 60 percent chance of showers, high near 17°C, with temperatures falling into the upper single digits Wednesday night.
Red Lake: Cloudy with a 40 percent chance of showers, high only 14°C, low around 9°C.
Sioux Lookout: Cloudy with a 40 percent chance of showers, high 15°C, overnight low near 8°C.
Armstrong: Cloudy with a 60 percent chance of showers, high around 16°C, falling to about 8°C Wednesday night.
Pickle Lake: Cloudy with a 60 percent chance of showers and a high of only 13°C. Wednesday night falls near 7°C.
Regional Three-Day Weather Trend
Monday is dominated by cloud, showers and developing heavy rain, particularly during the evening and overnight.
The 30-to-40-mm rainfall amounts forecast across Kenora, Dryden, Fort Frances, Red Lake and Sioux Lookout could produce ponding on roads and poor visibility during heavier downpours.
Tuesday starts wet but becomes warmer across the western half of the region. The bigger concern shifts from rainfall to strong southwest winds, with gusts reaching 60 km/h around Kenora and Red Lake and 50 km/h around Dryden, Ignace and Sioux Lookout.
Wednesday then feels dramatically different. Fort Frances falls from 27°C Tuesday to 17°C Wednesday, while Red Lake drops from 23°C to 14°C and Sioux Lookout from 24°C to 15°C.
Highway and Travel Outlook
This is a weather pattern drivers should take seriously, particularly Monday night.
Heavy rain may reduce visibility and leave water collecting on sections of Highways 17, 71, 72, 105 and 599.
Tuesday’s strong crosswinds could also affect higher-profile vehicles, trailers and campers on exposed stretches.
By Wednesday, road conditions become less stormy but remain wet in scattered showers.
Drivers should check Ontario 511 at 511.on.ca before longer trips for the latest highway conditions, incidents and construction information.
Boating and Outdoor Outlook
Monday evening and overnight are poor choices for recreational boating across much of Northwestern Ontario because of heavy rain, thunderstorms and strengthening winds.
Tuesday conditions improve from a rainfall perspective later in the day, but strong winds may make large lakes such as Lake of the Woods, Rainy Lake, Lac Seul and Wabigoon Lake rough and uncomfortable.
Wednesday will be much cooler, with lingering showers.
Anyone heading onto exposed water should check updated local forecasts immediately before departure.
Wardrobe Recommendations
Monday calls for waterproof clothing and footwear.
Tuesday will feel almost summer-like in Fort Frances, Dryden and Ignace, but a wind-resistant layer will be useful because of the strong southwest gusts.
Wednesday requires a definite change of wardrobe. With daytime temperatures falling into the 13°C to 17°C range across much of the region, a sweater, fleece or light jacket will be more comfortable.
Weather Trivia
Northwestern Ontario will experience one of September’s classic sharp temperature swings.
Fort Frances is forecast to reach 27°C Tuesday, roughly eight degrees above its normal early-September high near 19°C. Just one day later, Wednesday’s high falls to 17°C.
Red Lake sees an even more autumn-like Wednesday, reaching only 14°C, compared with its normal high near 17°C.
Source: Environment and Climate Change Canada Northern Ontario forecasts issued and updated early Monday, September 7, 2026. Forecasts may be revised as the heavy-rain system crosses the region.
Summary
Northwestern Ontario weather for September 7-9, 2026: Heavy rain and thunderstorms arrive Monday night, strong winds gust to 60 km/h Tuesday, and much cooler weather spreads across Kenora, Fort Frances, Dryden, Red Lake, Sioux Lookout, Armstrong and Pickle Lake Wednesday.
