From Sizzling Sunshine to Sweater-Ready Nights
TORONTO – WEATHER – Headed to The Big Smoke this weekend? Pack your sunscreen and your sweater—Toronto is giving us one last summer hurrah today before dipping its toes into a more typical fall forecast.
While the mornings may feel crisp, don’t be fooled—the heat is back (briefly) and it’s bringing a humidex punch along with it.
The Toronto Blue Jays are on the road this weekend, but the Montreal is in town to challenge the Argonauts in CFL action.
Thursday: Warm, Muggy, and a Bit Sneaky
At 7:00 AM EDT, Toronto Pearson International Airport reported mainly clear skies with a pleasant temperature of 15.0°C. The humidity is sitting at 79%, adding a bit of thickness to the air, and a light west-northwest breeze at 8 km/h is doing little to cool things down. Visibility is great at 24 km, and the barometric pressure is 101.6 kPa and falling, indicating change is on the way.
Today’s forecast calls for increasing cloudiness this afternoon, but not before we hit a high of 28°C—and with the humidex making it feel more like 33°C, you might think you’ve accidentally time-warped back to July. Winds will pick up from the northwest at 20 km/h later in the day, offering a bit of relief from the late-summer steam. The UV index is 6, which is high, so sunglasses and sunscreen are definitely still in season.
If you’re wondering how unusual this is, Toronto’s record high for September 18 is 32.8°C, while the record low is 5.6°C. So while today’s heat isn’t record-breaking, it’s definitely not your average mid-September vibe either.
Tonight: Partly Cloudy and Cooler
Tonight, skies will be partly cloudy, with north winds at 20 km/h bringing in a cooler air mass. The overnight low drops to 13°C, making for a comfortable, crisp night. Great sleeping weather, or a good excuse to cozy up on a patio with a warm drink.
Friday: Clouds in the Morning, Sunshine by Afternoon
Friday, September 19, starts off mainly cloudy, but the sun isn’t staying hidden for long. Expect clearing early in the afternoon, with a high of 21°C—a noticeable drop from Thursday’s sizzle, but still very pleasant. The UV index remains high at 6, so don’t ditch the sunscreen just yet. Friday night will bring cloudy periods and a cooler low of 9°C, so you might finally need that fall jacket.
Saturday: Classic Fall Chill
Saturday, September 20, will feature a mix of sun and cloud, and temperatures will be cooler, with a high of 19°C—perfect for fall fairs, apple picking, or a brisk stroll through High Park. The overnight low will be 10°C, cool but not cold—ideal for layering up.
Sunday Brings the Warmth Back (For a Moment)
Sunday, September 21, brightens up again with a mix of sun and cloud and a lovely high of 24°C—a little late September bonus! But keep in mind, Sunday night brings a 30 percent chance of showers along with cloudy skies and a low of 15°C. So, maybe move that evening BBQ indoors just in case.
What to Wear?
Today: Think July, not September—light, breathable clothing and sun protection.
Friday and Saturday: Transition layers—T-shirt by day, hoodie by night.
Sunday: More summer gear during the day, but bring a rain jacket just in case for the evening.
Weather Trivia: Did You Know?
Toronto’s proximity to Lake Ontario plays a big role in its temperature swings this time of year. Warm air can linger longer thanks to the lake’s moderating effect, which is why late-season heat waves like today’s aren’t unheard of—even if they feel totally out of place when the pumpkin spice hits the shelves.
