Current Conditions

Sarnia, Ontario

76°F25°C

Rain

Wind

NE 5 mph8 km/h

Humidity

85%

Cloud Cover

85%

As of Wednesday, September 2, 2026 at 6:31 PM EDT

Today's Outlook

Night

Mostly cloudy, with a low around 74°F23°C. Light wind from the E around 5 mph7 km/h. 92% chance of rain throughout the night.

7-Day Forecast

Condition	High (°F)	Low (°F)	Precip (mm)	Cloud Cover (%)	Wind (mph)
Rain	High 88°F31°CFeels 96°F35°C	Low 74°F23°C	Precip 0.48 in12.1 mm92%	Cloud 82%	Wind WSW 6 mph10 km/h	Wednesday: Overcast and hot, with a high of 88°F31°C — feels like 95°F35°C. Breezy from the WSW at 8 mph12 km/h. 82% chance of rain throughout the day. Heat risk in the afternoon. Wednesday Night: Mostly cloudy, with a low around 74°F23°C. Light wind from the E around 5 mph7 km/h. 92% chance of rain throughout the night.
Rain	High 81°F27°C	Low 71°F22°C	Precip 0.39 in9.9 mm80%	Cloud 71%	Wind WNW 4 mph7 km/h	Thursday: Overcast and warm, with a high of 81°F27°C and morning low of 71°F22°C. Light wind from the WNW around 4 mph7 km/h. 75% chance of rain throughout the day. Heavy, humid air. Thursday Night: Mostly cloudy, with a low around 71°F22°C. Light wind from the W around 5 mph7 km/h. 80% chance of rain throughout the night.
Light Rain	High 76°F24°C	Low 70°F21°C	Precip 0.28 in7.1 mm61%	Cloud 82%	Wind N 6 mph9 km/h	Friday: Overcast and warm, with a high of 76°F24°C and morning low of 70°F21°C. Breezy from the N at 5 to 7 mph9 to 12 km/h. 45% chance of light rain throughout the day. Humid. Friday Night: Mostly cloudy, with a low around 70°F21°C. Breezy from the N at 6 to 8 mph10 to 13 km/h. 61% chance of showers throughout the night.
Clear	High 75°F24°C	Low 67°F19°C	Precip 0.01 in0.3 mm6%	Cloud 23%	Wind NNE 9 mph14 km/h	Saturday: Mostly clear and warm, with a high of 75°F24°C and morning low of 67°F19°C. Breezy from the NNE at 9 to 11 mph14 to 18 km/h. Saturday Night: Mostly clear, with a low around 67°F19°C. Breezy from the NNE at 9 to 11 mph14 to 18 km/h.
Clear	High 76°F24°C	Low 64°F18°C	Precip 0 in0 mm—	Cloud 32%	Wind NE 6 mph10 km/h	Sunday: Partly cloudy and warm, with a high of 76°F24°C and morning low of 64°F18°C. Breezy from the NE at 6 to 7 mph10 to 11 km/h. Sunday Night: Partly cloudy, with a low around 64°F18°C. Breezy from the NE at 6 to 7 mph10 to 12 km/h.
Partly Cloudy	High 77°F25°C	Low 63°F17°C	Precip 0 in0.1 mm1%	Cloud 44%	Wind E 5 mph9 km/h	Monday: Partly cloudy and warm, with a high of 77°F25°C and morning low of 64°F18°C. Light wind from the E around 5 mph8 km/h. Monday Night: Mostly cloudy, with a low around 63°F17°C. Light wind from the E around 6 mph9 km/h.
Partly Cloudy	High 78°F26°C	Low 64°F18°C	Precip 0.01 in0.3 mm8%	Cloud 75%	Wind SE 8 mph12 km/h	Tuesday: Mostly cloudy and warm, with a high of 78°F26°C and morning low of 65°F18°C. Breezy from the SE at 7 to 9 mph12 to 14 km/h. Tuesday Night: Mostly cloudy, with a low around 64°F18°C. Breezy from the SSE at 8 to 10 mph12 to 16 km/h.

15-Day Forecast

	Day	High	Low	Precip	Cloud Cover	Condition	Wind
	WednesdaySep 2	88°F31°C Feels 96°F35°C	74°F23°C	0.48 in12.1 mm· 92%	82%	Rain	WSW 6 mph10 km/h
DayOvercast and hot, with a high of 88°F31°C — feels like 95°F35°C. Breezy from the WSW at 8 mph12 km/h. 82% chance of rain throughout the day. Heat risk in the afternoon. NightMostly cloudy, with a low around 74°F23°C. Light wind from the E around 5 mph7 km/h. 92% chance of rain throughout the night.
	ThursdaySep 3	81°F27°C	71°F22°C	0.39 in9.9 mm· 80%	71%	Rain	WNW 4 mph7 km/h
DayOvercast and warm, with a high of 81°F27°C and morning low of 71°F22°C. Light wind from the WNW around 4 mph7 km/h. 75% chance of rain throughout the day. Heavy, humid air. NightMostly cloudy, with a low around 71°F22°C. Light wind from the W around 5 mph7 km/h. 80% chance of rain throughout the night.
	FridaySep 4	76°F24°C	70°F21°C	0.28 in7.1 mm· 61%	82%	Light Rain	N 6 mph9 km/h
DayOvercast and warm, with a high of 76°F24°C and morning low of 70°F21°C. Breezy from the N at 5 to 7 mph9 to 12 km/h. 45% chance of light rain throughout the day. Humid. NightMostly cloudy, with a low around 70°F21°C. Breezy from the N at 6 to 8 mph10 to 13 km/h. 61% chance of showers throughout the night.
	SaturdaySep 5	75°F24°C	67°F19°C	0.01 in0.3 mm· 6%	23%	Clear	NNE 9 mph14 km/h
DayMostly clear and warm, with a high of 75°F24°C and morning low of 67°F19°C. Breezy from the NNE at 9 to 11 mph14 to 18 km/h. NightMostly clear, with a low around 67°F19°C. Breezy from the NNE at 9 to 11 mph14 to 18 km/h.
	SundaySep 6	76°F24°C	64°F18°C	0 in0 mm· —	32%	Clear	NE 6 mph10 km/h
DayPartly cloudy and warm, with a high of 76°F24°C and morning low of 64°F18°C. Breezy from the NE at 6 to 7 mph10 to 11 km/h. NightPartly cloudy, with a low around 64°F18°C. Breezy from the NE at 6 to 7 mph10 to 12 km/h.
	MondaySep 7	77°F25°C	63°F17°C	0 in0.1 mm· 1%	44%	Partly Cloudy	E 5 mph9 km/h
DayPartly cloudy and warm, with a high of 77°F25°C and morning low of 64°F18°C. Light wind from the E around 5 mph8 km/h. NightMostly cloudy, with a low around 63°F17°C. Light wind from the E around 6 mph9 km/h.
	TuesdaySep 8	78°F26°C	64°F18°C	0.01 in0.3 mm· 8%	75%	Partly Cloudy	SE 8 mph12 km/h
DayMostly cloudy and warm, with a high of 78°F26°C and morning low of 65°F18°C. Breezy from the SE at 7 to 9 mph12 to 14 km/h. NightMostly cloudy, with a low around 64°F18°C. Breezy from the SSE at 8 to 10 mph12 to 16 km/h.
	WednesdaySep 9	85°F29°C Feels 89°F32°C	71°F22°C	0.11 in2.7 mm· 23%	60%	Showers	SW 10 mph17 km/h
DayMostly cloudy and warm, with a high of 85°F29°C and morning low of 72°F22°C. Breezy from the SW at 11 mph17 km/h. 23% chance of showers throughout the day. Humid. NightMostly cloudy, with a low around 71°F22°C. Breezy from the SSW at 10 mph16 km/h. 19% chance of drizzle throughout the night.
	ThursdaySep 10	78°F26°C	69°F21°C	0.19 in4.8 mm· 25%	59%	Showers	WNW 10 mph16 km/h
DayMostly cloudy and warm, with a high of 78°F26°C and morning low of 71°F22°C. Breezy from the WNW at 10 to 11 mph16 to 17 km/h. 25% chance of showers throughout the day. Humid. NightMostly cloudy, with a low around 69°F21°C. Breezy from the WNW at 10 mph15 km/h. 20% chance of showers throughout the night.
	FridaySep 11	74°F24°C	65°F19°C	0.1 in2.5 mm· 21%	52%	Drizzle	WNW 9 mph14 km/h
DayMostly cloudy and warm, with a high of 74°F24°C and morning low of 65°F19°C. Breezy from the WNW at 9 mph14 km/h. 21% chance of drizzle throughout the day. NightPartly cloudy, with a low around 66°F19°C. Breezy from the NW at 8 to 9 mph14 to 14 km/h. 15% chance of drizzle throughout the night.
	SaturdaySep 12	77°F25°C	65°F18°C	0.13 in3.3 mm· 18%	54%	Showers	SSW 9 mph15 km/h
DayMostly cloudy and warm, with a high of 77°F25°C and morning low of 65°F19°C. Breezy from the SW at 10 mph15 km/h. 18% chance of showers throughout the day. NightPartly cloudy, with a low around 65°F18°C. Breezy from the SSW at 9 to 10 mph14 to 15 km/h. 14% chance of showers throughout the night.
	SundaySep 13	77°F25°C	67°F19°C	0.1 in2.5 mm· 17%	56%	Showers	SSW 10 mph16 km/h
DayMostly cloudy and warm, with a high of 77°F25°C and morning low of 67°F19°C. Breezy from the SSW at 10 to 11 mph16 to 17 km/h. 17% chance of drizzle throughout the day. NightMostly cloudy, with a low around 67°F19°C. Breezy from the SSW at 9 to 10 mph15 to 16 km/h. 17% chance of showers throughout the night.
	MondaySep 14	77°F25°C	67°F19°C	0.09 in2.4 mm· 15%	56%	Drizzle	SSW 10 mph16 km/h
DayMostly cloudy and warm, with a high of 77°F25°C and morning low of 67°F19°C. Breezy from the SW at 10 to 11 mph16 to 17 km/h. 14% chance of drizzle throughout the day. NightMostly cloudy, with a low around 67°F20°C. Breezy from the SSW at 9 to 10 mph15 to 15 km/h. 15% chance of drizzle throughout the night.
	TuesdaySep 15	75°F24°C	66°F19°C	0.15 in3.7 mm· 20%	50%	Showers	SW 9 mph15 km/h
DayMostly cloudy and warm, with a high of 75°F24°C and morning low of 66°F19°C. Breezy from the WSW at 10 mph16 km/h. 20% chance of showers throughout the day. NightPartly cloudy, with a low around 66°F19°C. Breezy from the SW at 9 mph15 km/h. 17% chance of showers throughout the night.
	WednesdaySep 16	73°F23°C	63°F17°C	0.09 in2.2 mm· 17%	52%	Drizzle	NW 9 mph14 km/h
DayMostly cloudy and warm, with a high of 73°F23°C and morning low of 63°F17°C. Breezy from the NW at 9 to 10 mph15 to 15 km/h. 17% chance of drizzle throughout the day. NightPartly cloudy, with a low around 64°F18°C. Breezy from the NNW at 9 mph14 km/h. 15% chance of drizzle throughout the night.

Nearby Cities

Strathroy40 mi64 km Chatham41 mi65 km Tecumseh52 mi83 km Windsor56 mi91 km London59 mi95 km LaSalle61 mi98 km

About This Forecast

This forecast is powered by WeatherMesh, the world's most advanced and accurate weather model powered by AI. WeatherMesh is built on proprietary data from WindBorne's Global Sounding Balloon constellation — the world's largest fleet of autonomous, long-duration weather balloons — collecting observations across 100% of Earth, including over oceans and remote regions where no other data exists.

WeatherMesh consistently outperforms legacy models in independent benchmarks. View Benchmarks →

Access WeatherMesh forecasts programmatically via our API. API Documentation →

How to Access Weather Forecasts

Pattern	Example	Description
/weather/{country}/{city}/	/weather/united-states/san-francisco/	City forecast (canonical URL)
/weather/{city}/	/weather/tokyo/	Shorthand — redirects to most populous match
/weather/{country}/{region}/{city}/	/weather/united-states/california/san-francisco/	With region — redirects to canonical
/weather/nearby?lat={lat}&lon={lon}	/weather/nearby?lat=48.1&lon=11.5	Find nearest city by coordinates
/weather/{country}/	/weather/germany/	Country index — all cities by region

Country and city names use lowercase slugs with hyphens (e.g. united-states, san-francisco). Arbitrary city names are supported — if not in our database, we geocode the name and serve the forecast for that location.

For programmatic access, use theWindBorne Forecast APIwhich returns structured JSON for any coordinates worldwide.

Coordinates: 42.9787°N, 82.4041°W·Elevation: 185m·Timezone: America/Toronto·Population: 72,125