THUNDER BAY – WEATHER DESK – Northern Ontario’s fly-in communities can expect a changeable stretch of early autumn weather, with cloudy skies, scattered showers and noticeably cooler conditions near Hudson Bay.
The western and central Far North should begin warming by Friday. Communities along the Hudson Bay and James Bay coasts will remain cooler, with daytime temperatures generally between 9°C and 14°C.
No Environment and Climate Change Canada weather alerts were posted for the communities covered in this report early Wednesday morning.
Conditions can change quickly, so residents and travellers should continue checking the official weather-alert map.
Wednesday, September 16: Clouds, Sunshine and Scattered Showers
Fort Severn and Peawanuck: Expect a mixture of cloud and sunshine at Fort Severn, while Peawanuck remains mainly cloudy and breezy. Highs will range from 13°C to 15°C. Overnight lows will fall to approximately 6°C.
Attawapiskat and the James Bay coast: Cloudy and cooler conditions are expected, with a high near 12°C. The overnight low will be close to 6°C.
Sachigo Lake and Sandy Lake: Sachigo Lake will see sunshine giving way to increasing cloud, with a high near 13°C. Sandy Lake may receive a passing shower, with a high near 12°C. Overnight lows will be close to 6°C.
Kasabonika Lake and Webequie: Mainly cloudy conditions are expected. Kasabonika Lake should reach 14°C, while Webequie will have a high near 12°C. Overnight lows will range from 6°C to 8°C.
Marten Falls: Partial sunshine is expected with a high near 13°C and an overnight low near 6°C.
Pikangikum: Periods of rain or drizzle are possible. The daytime high will be close to 12°C, with an overnight low near 7°C.
Thursday, September 17: Cooler and Showery in the Far North
Fort Severn and Peawanuck: Thursday will be the coolest day of the forecast period. Showers and gusty winds are possible, with highs near 9°C. Fort Severn could fall to the freezing mark Thursday night, while Peawanuck drops to approximately 3°C.
Attawapiskat: A mixture of sun and cloud is expected, with showers possible during the afternoon. The high will be near 12°C, followed by an overnight low of 5°C.
Sachigo Lake and Sandy Lake: Sachigo Lake may receive morning showers before some afternoon sunshine develops. Sandy Lake should see partly to mainly sunny skies. Highs will range from 11°C to 13°C, with overnight lows between 2°C and 4°C.
Kasabonika Lake: A morning shower is possible before skies begin to break. Breezy conditions are expected, with a high near 10°C. Temperatures could fall to approximately -1°C Thursday night, creating a risk of frost and slippery surfaces.
Webequie: Morning showers may be followed by sunny breaks. It will be breezy, with a high near 13°C and an overnight low close to 2°C.
Marten Falls: Expect partly sunny skies with a brief shower possible. Winds may become stronger during the afternoon. The high will be near 16°C, falling to 4°C overnight.
Pikangikum: Thursday should be mainly sunny, with a high near 14°C and an overnight low close to 3°C.
Friday, September 18: Warmer in the West, Cool Near James Bay
Fort Severn and Peawanuck: Temperatures will recover slightly. Fort Severn should reach 14°C with some sunshine before cloud increases. Peawanuck will become cloudy with a similar high of 14°C.
Attawapiskat: Considerable cloudiness and a few showers are possible. The high will remain near 12°C, with temperatures falling to approximately 2°C Friday night.
Sachigo Lake and Sandy Lake: Friday will be the most comfortable day of the three-day forecast. Sachigo Lake should reach 17°C under mainly sunny skies, while Sandy Lake reaches approximately 16°C.
Kasabonika Lake: Mainly cloudy skies are expected, with rain or drizzle possible during the afternoon. The high will be near 15°C.
Webequie and Marten Falls: A mixture of sun and cloud is expected, but afternoon showers cannot be ruled out. Highs will be close to 14°C.
Pikangikum: Mostly cloudy conditions are expected, with a high near 18°C and an overnight low near 9°C.
Three-Day Temperature Outlook
| Community | Wednesday | Thursday | Friday |
|---|---|---|---|
| Fort Severn | 15°C / 6°C | 9°C / 0°C | 14°C / 6°C |
| Peawanuck | 13°C / 6°C | 9°C / 3°C | 14°C / 4°C |
| Attawapiskat | 12°C / 6°C | 12°C / 5°C | 12°C / 2°C |
| Sachigo Lake | 13°C / 6°C | 11°C / 2°C | 17°C / 8°C |
| Sandy Lake | 12°C / 6°C | 13°C / 4°C | 16°C / 6°C |
| Kasabonika Lake | 14°C / 8°C | 10°C / -1°C | 15°C / 6°C |
| Webequie | 12°C / 6°C | 13°C / 2°C | 14°C / 7°C |
| Marten Falls | 13°C / 6°C | 16°C / 4°C | 14°C / 4°C |
| Pikangikum | 12°C / 7°C | 14°C / 3°C | 18°C / 9°C |
Flying and Travel Conditions
Periods of rain, low cloud and stronger winds may affect flights, particularly around Fort Severn, Peawanuck, Pikangikum and several central Far North communities.
Passengers should confirm departure times directly with their airline or community airport before travelling. Local airport observations and aviation forecasts should always take priority over a general public forecast.
Thursday night could bring frost to Kasabonika Lake and near-freezing temperatures at Fort Severn. Residents should protect sensitive plants, drain exposed hoses and use caution on wooden steps, docks and boardwalks early Friday.
What to Wear
Layered clothing will be important. A waterproof jacket, warm sweater and sturdy footwear will be useful where showers are expected. Travellers heading toward Hudson Bay should prepare for wind making temperatures feel colder than the forecast high.
Forecasts are based on information available Wednesday morning, September 16, 2026. Conditions can change quickly across Northern Ontario.
Check the latest Environment and Climate Change Canada forecast before travelling.
