Thunder Bay – WEATHER — SATURDAY, SEPTEMBER 12, 2026 — Northwestern Ontario is settling into a cool September weekend, with scattered showers continuing across several communities Saturday and Sunday.
Monday will bring a significant change. Rain is expected to spread across much of the Kenora, Rainy River, Dryden, Sioux Lookout, Red Lake and Highway 17 areas. Wet roads and reduced visibility could make Monday afternoon and evening travel more difficult.
The coldest overnight temperatures are expected Sunday night. Fort Frances, Emo and Atikokan could fall to between 1°C and 2°C, while Ignace, Greenstone, Longlac, Nipigon, Terrace Bay and Marathon could dip to around 2°C or 3°C.
Kenora and Lake of the Woods
Saturday: A mixture of cloud and sunny breaks, with one or two brief showers possible. Cooler, with a high near 13°C. Low near 6°C.
Sunday: Mostly sunny, although an isolated shower cannot be ruled out. High near 14°C. Low near 8°C.
Monday: Rain spreading across the area. Winds will become breezy during the afternoon. High near 15°C. Low near 10°C.
Travel outlook: Monday will bring wet roads and lower visibility along Highway 17, Highway 71 and routes around Lake of the Woods.
Dryden and Vermilion Bay
Saturday: Partly sunny and cooler, with scattered showers—mainly later in the day around Dryden and earlier near Vermilion Bay. High near 14°C. Low between 6°C and 7°C.
Sunday: Mostly sunny with a chance of a passing shower. High near 14°C. Low near 6°C.
Monday: Some morning sun and high cloud near Dryden, followed by rain during the afternoon. Vermilion Bay could see rain for a larger part of the day. High near 16°C. Low near 11°C.
Travel outlook: Conditions should be reasonable Sunday, but Monday rain may produce spray, slick pavement and reduced visibility along Highway 17.
Fort Frances, Emo and Rainy River
Saturday: Cooler and breezy. Fort Frances and Rainy River may see a few morning showers, followed by variable cloud and sunny breaks. Emo should remain mainly dry with partial sunshine. Highs from 14°C to 15°C. Lows from 5°C to 7°C.
Sunday: Mostly sunny and cool, with highs near 16°C. Temperatures could fall to approximately 1°C in Fort Frances and Emo overnight, with Rainy River near 3°C.
Monday: Periods of rain becoming steadier. Rainy River will remain slightly cooler, with a high near 14°C, while Fort Frances and Emo reach approximately 16°C to 17°C. Overnight lows near 10°C to 11°C.
Weather concern: Patchy frost is possible in colder rural and low-lying locations Sunday night. Gardeners may want to protect sensitive plants.
Sioux Lookout
Saturday: A mix of sun and cloud with a couple of showers, mainly later in the day. High near 15°C. Low near 7°C.
Sunday: Sunshine mixed with a few clouds and a chance of an isolated shower. High near 13°C. Low near 5°C.
Monday: High, thin cloud during the morning, followed by periods of afternoon rain. High near 16°C. Low near 11°C.
Travel outlook: Rain could affect Highway 72 and local aviation operations Monday afternoon. Travellers should confirm flight schedules before leaving for the airport.
Red Lake and Ear Falls
Saturday: Some early sunshine followed by increasing cloud and one or two showers. Cooler, with highs near 14°C. Lows near 7°C.
Sunday: Mostly sunny with an isolated shower possible. Highs near 13°C to 14°C. Lows from 5°C to 6°C.
Monday: Rain across the region. Red Lake and Ear Falls should reach approximately 16°C. Overnight lows from 8°C to 9°C.
Travel outlook: Expect wet conditions along Highway 105 on Monday. Areas of heavier rain could briefly reduce visibility.
Atikokan
Saturday: Cooler, with clouds and sunny breaks. A thunderstorm is possible during the morning, followed by a few afternoon showers. High near 16°C. Low near 6°C.
Sunday: Partial sunshine with a chance of a shower. High near 15°C. Low near 2°C.
Monday: High cloud during the morning, followed by periods of afternoon rain. High near 16°C. Low near 10°C.
Weather concern: Sunday night will be cold enough for possible patchy frost outside the townsite.
Ignace
Saturday: Cooler with a mix of sun and cloud. A couple of afternoon showers are possible. High near 15°C. Low near 6°C.
Sunday: Mostly sunny with a slight chance of a shower. High near 13°C. Low near 3°C.
Monday: Thickening cloud followed by rain during much of the afternoon. High near 16°C. Low near 10°C.
Travel outlook: Monday afternoon rain may create poor driving conditions along Highway 17 east and west of Ignace.
Greenstone, Geraldton, Longlac and Nakina
Saturday: Mostly cloudy and cooler. Geraldton and the Greenstone area will see scattered showers or light rain, while Longlac may receive a few morning showers. Highs near 20°C. Lows from 6°C to 7°C.
Sunday: A mixture of sun and cloud with a chance of a passing shower. Cooler, with highs near 13°C. Overnight temperatures will fall to approximately 2°C or 3°C.
Monday: Some early sun near Longlac, followed by increasing cloud across the region. Highs from 17°C to 18°C. Lows near 10°C to 11°C.
Weather concern: Near-frost temperatures are possible Sunday night, especially away from Lake Nipigon and in sheltered inland areas.
Nipigon and Red Rock
Saturday: Periods of rain and a possible morning thunderstorm, followed by mostly cloudy conditions. High near 21°C. Low near 8°C.
Sunday: Partly sunny and cooler with one or two passing showers. High near 15°C. Low near 3°C.
Monday: Some early sun, followed by increasing cloud and afternoon rain. High near 17°C. Low near 12°C.
Travel outlook: Drivers should watch for changing visibility on Highway 11/17 during Saturday showers and again when rain returns Monday.
Terrace Bay, Schreiber and Marathon
Saturday: Morning showers followed by increasing sunny breaks in Terrace Bay and Schreiber. Marathon will see morning showers before a mix of sun and cloud develops. Highs near 21°C. Lows from 9°C to 10°C.
Sunday: Cooler and mainly cloudy to partly sunny, with passing showers possible. Highs near 14°C to 15°C. Lows near 3°C.
Monday: Increasing cloud. Terrace Bay, Schreiber and Marathon should reach approximately 16°C. Rain may remain west of this corridor for much of the day, but travellers should monitor later forecasts. Overnight lows near 12°C to 13°C.
Northwestern Ontario Travel Outlook
Saturday: Scattered showers and isolated thunder may produce brief reductions in visibility. Conditions will vary considerably over short distances.
Sunday: Generally the best travel day, with more sunshine. A few isolated showers remain possible. Cold overnight temperatures may create frost in low-lying areas.
Monday: The poorest widespread travel conditions of the three-day period. Rain will move across western and central Northwestern Ontario, bringing wet pavement, road spray and reduced visibility.
Before travelling, check the latest Ontario 511 road conditions and Environment Canada forecasts and alerts.
Summary: Northwestern Ontario’s three-day forecast calls for a cool weekend, scattered showers and near-frost temperatures before widespread rain arrives Monday.
