Current Conditions

Thornhill, Ontario

66°F19°C
Rain

Wind

SE 6 mph10 km/h

Humidity

83%

Cloud Cover

99%

As of Tuesday, September 8, 2026 at 11:18 PM EDT

Today's Outlook

Night

Overcast, with a low around 66°F19°C. Breezy from the SW at 8 to 12 mph13 to 19 km/h. 89% chance of light rain before dawn.

7-Day Forecast

DayConditionHigh (°F)Low (°F)Precip (mm)Cloud Cover (%)Wind (mph)
RainHigh 73°F23°CLow 66°F19°CPrecip 0.43 in11 mm97%Cloud 92%Wind SW 9 mph14 km/hWednesday: Overcast and warm, with a high of 73°F23°C and morning low of 68°F20°C. Breezy from the SW at 10 to 13 mph16 to 21 km/h. 97% chance of rain throughout the day. Humid. Wednesday Night: Overcast, with a low around 66°F19°C. Breezy from the SW at 8 to 12 mph13 to 19 km/h. 89% chance of light rain before dawn.
Partly CloudyHigh 73°F23°CLow 58°F15°CPrecip 0 in0 mmCloud 61%Wind WNW 9 mph15 km/hThursday: Overcast and warm, with a high of 73°F23°C and morning low of 64°F18°C. Breezy from the WNW at 10 to 11 mph16 to 18 km/h. Thursday Night: Partly cloudy, with a low around 58°F15°C. Breezy from the WNW at 9 to 11 mph14 to 17 km/h.
ClearHigh 72°F22°CLow 52°F11°CPrecip 0 in0 mmCloud 12%Wind W 5 mph8 km/hFriday: Mostly clear and warm, with a high of 72°F22°C and morning low of 53°F12°C. Light wind from the W around 4 mph7 km/h. Friday Night: Mostly clear, with a low around 52°F11°C. Light wind from the WSW around 6 mph9 km/h.
Partly CloudyHigh 75°F24°CLow 56°F14°CPrecip 0.03 in0.8 mm9%Cloud 48%Wind SSE 6 mph10 km/hSaturday: Partly cloudy and warm, with a high of 75°F24°C and morning low of 58°F15°C. Breezy from the SSE at 7 to 8 mph11 to 13 km/h. Saturday Night: Mostly cloudy, with a low around 56°F14°C. Light wind from the SSE around 6 mph10 km/h.
DrizzleHigh 75°F24°CLow 60°F16°CPrecip 0.05 in1.3 mm12%Cloud 45%Wind WNW 9 mph14 km/hSunday: Mostly cloudy and warm, with a high of 75°F24°C and morning low of 65°F18°C. Breezy from the WNW at 9 to 11 mph14 to 18 km/h. 12% chance of drizzle throughout the day. Sunday Night: Partly cloudy, with a low around 60°F16°C. Breezy from the WNW at 8 to 10 mph14 to 16 km/h.
Partly CloudyHigh 68°F20°CLow 55°F13°CPrecip 0.03 in0.7 mm9%Cloud 48%Wind NNW 7 mph12 km/hMonday: Mostly cloudy and warm, with a high of 68°F20°C and morning low of 55°F13°C. Breezy from the NNW at 7 mph11 km/h. Dry air. Monday Night: Partly cloudy, with a low around 55°F13°C. Breezy from the NNW at 8 mph12 km/h.
ShowersHigh 76°F24°CLow 59°F15°CPrecip 0.15 in3.9 mm34%Cloud 69%Wind SSW 11 mph18 km/hTuesday: Mostly cloudy and warm, with a high of 76°F24°C and morning low of 63°F17°C. Breezy from the SSW at 12 to 14 mph20 to 23 km/h. 32% chance of light rain throughout the day. Tuesday Night: Mostly cloudy, with a low around 59°F15°C. Breezy from the S at 9 to 10 mph15 to 16 km/h. 34% chance of showers throughout the night.

15-Day Forecast

Day High Low Precip Cloud Cover Condition Wind
WednesdaySep 973°F23°C66°F19°C0.43 in11 mm· 97%92%RainSW 9 mph14 km/h
ThursdaySep 1073°F23°C58°F15°C0 in0 mm· —61%Partly CloudyWNW 9 mph15 km/h
FridaySep 1172°F22°C52°F11°C0 in0 mm· —12%ClearW 5 mph8 km/h
SaturdaySep 1275°F24°C56°F14°C0.03 in0.8 mm· 9%48%Partly CloudySSE 6 mph10 km/h
SundaySep 1375°F24°C60°F16°C0.05 in1.3 mm· 12%45%DrizzleWNW 9 mph14 km/h
MondaySep 1468°F20°C55°F13°C0.03 in0.7 mm· 9%48%Partly CloudyNNW 7 mph12 km/h
TuesdaySep 1576°F24°C59°F15°C0.15 in3.9 mm· 34%69%ShowersSSW 11 mph18 km/h
WednesdaySep 1672°F22°C62°F17°C0.14 in3.6 mm· 26%61%ShowersNW 7 mph11 km/h
ThursdaySep 1771°F22°C59°F15°C0.15 in3.8 mm· 26%65%ShowersS 8 mph12 km/h
FridaySep 1869°F20°C58°F15°C0.15 in3.8 mm· 24%59%ShowersWNW 10 mph16 km/h
SaturdaySep 1965°F18°C55°F13°C0.11 in2.7 mm· 17%53%DrizzleWNW 9 mph15 km/h
SundaySep 2062°F17°C52°F11°C0.09 in2.4 mm· 15%54%DrizzleNW 8 mph14 km/h
MondaySep 2162°F17°C49°F10°C
Feels 46°F8°C
0.11 in2.7 mm· 17%50%ShowersN 8 mph13 km/h
TuesdaySep 2264°F18°C51°F10°C0.11 in2.9 mm· 15%50%ShowersENE 8 mph13 km/h
WednesdaySep 2365°F19°C52°F11°C0.07 in1.9 mm· 15%53%DrizzleS 8 mph13 km/h

Nearby Cities

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

PatternExampleDescription
/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=11.5Find 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: 43.8150°N, 79.4242°W·Elevation: 175m·Timezone: America/Toronto·Population: 115,292