Last updated: April 22, 2025
In September, Toronto experiences a dynamic range of weather that showcases the transition from summer to fall. Temperatures can soar to a warm maximum of 33°C (91°F), while the average hovers around a comfortable 17°C (64°F). However, early risers may feel the brisk chill of a minimum of 3°C (38°F). With 58 mm (2.3 in) of precipitation over 8 days, occasional rainfall adds a refreshing touch to the city’s autumn ambiance. Additionally, the humidity level stays relatively high at 76%, contributing to a lush and vibrant atmosphere as the leaves begin to change. Whether soaking in the warmth or enjoying the crisp air, September in Toronto offers a unique blend of seasonal experiences.
As summer fades into autumn, September in Toronto offers a delightful transition marked by a refreshing drop in temperatures. The month begins with early signs of fall, where nighttime lows average around 3°C (38°F), allowing for cool evenings that hint at the chill of winter to come. Daytime temperatures, however, remain pleasantly warm, peaking at 33°C (91°F), which echoes the lingering warmth of summer. With an overall average of 17°C (64°F), September invites both comfort and crispness, perfect for outdoor activities. As the month progresses, the blend of warmth during the day and cooler nights creates an ideal atmosphere to enjoy the vibrant fall foliage that begins to envelop the city.
September brings a gentle transition into the layering of autumn in Toronto, with precipitation averaging 58 mm (2.3 in) over about 8 days. This marks a noticeable dip from the wetter summer months, where July and August each saw around 78 mm, reflecting a shift towards dryer conditions. As the city prepares for October, which typically experiences a significant uptick in rainfall at about 95 mm (3.7 in) over 13 days, September serves as a bridge—offering a brief respite from the heavier storms that often characterize the fall season. This slight decrease in precipitation showcases the changing season, inviting residents to enjoy the mild weather before the briskness of autumn fully sets in.
As summer gives way to autumn, September in Toronto experiences a slight uptick in humidity, averaging around 76%. This marks a gentle increase from the drier months of July and August, which post their lowest levels at 77% and 72% respectively. With this transition, the city begins to feel a bit more moisture in the air, echoing the lushness of early fall as nature prepares for the changing season. Nevertheless, September's humidity remains significantly lower than the winter months, where figures soar to a high of 91% in both January and February. Overall, this month offers a refreshing blend of warmth and crispness, inviting Torontonians to enjoy the outdoors before the chill of October sets in.
As summer fades into autumn, Toronto's September UV Index reflects a notable shift in sun exposure, sitting at a moderate level of 7. This marks a decrease from the peak of 9 experienced during the sweltering summer months, where burn times plummeted to just 15 minutes. In September, residents can enjoy 25 minutes of safe sun exposure, signifying a transition to a high exposure category that still warrants caution. As the season changes, it's essential to remain mindful of UV levels and protect your skin — reasons why keeping informed with resources like the Toronto UV Index is crucial. Remember, while the intensity may diminish compared to July and August, the sun can still pose risks, especially during peak hours.
UV Risk Categories
September in Toronto is truly a transitional month, offering 306 hours of sunshine that signals the tail end of summer’s warmth. Following the peak summer months of July and August, which bask in 351 and 344 hours of sunlight respectively, September retains much of that golden glow while seamlessly ushering in the crispness of fall. This pleasant abundance of sunshine allows Torontonians to relish outdoor activities, from leisurely strolls in urban parks to vibrant harvest festivals. As daylight begins to wane in the approaching months of October and November, with significantly lower hours of sunshine at 204 and 154, September stands out as a perfect month for enjoying the lingering warmth and vibrant autumn colors that make this city so enchanting.
In September, Toronto enjoys a promising likelihood of sunny weather, with sunshine chances at 46%. This figure is comparable to the sunny outlook of August (49%), indicating that the late summer warmth often lingers into early fall. Interestingly, it's a period where the probability of sunshine starts to remain relatively stable, coming off the slightly fluctuating months of summer, like July (43%) and June (42%). As the city transitions into autumn, sunshine chances decline sharply in the subsequent months, with October plummeting to just 28%. Therefore, September stands out as a delightful opportunity for outdoor activities before the cooler weather sets in.
As summer gracefully transitions into fall, September in Toronto brings a gentle reduction in daylight, averaging around 12 hours. Following the sun-drenched days of July and August, which boasted 15 and 13 hours respectively, September signals the beginning of shorter days. This month is a poignant reminder of nature’s cyclical rhythm, as daylight begins its slow descent towards winter, with October set to offer just 10 hours. While we bid farewell to the long summer evenings, September still bestows a significant amount of daylight, inviting residents to savor the vibrant hues of early autumn before the darker months envelop the city.
As summer fades into autumn, September in Toronto experiences a gentle revival in wind speeds, averaging 3.7 m/s (8 mph). This marks a welcome increase from the lighter breezes of August, which lingered at 2.9 m/s (6 mph). Throughout the year, the wind speed tends to oscillate, with the heights of winter, such as 4.4 m/s (10 mph) in December, contrasting the calmer months of late summer. The transition into fall signals a stable wind pattern that continues into October, which matches September’s average. As the leaves start to turn, the invigorating September winds beckon residents outdoors, reminding them of the gentle shift from the warmth of summer to the crispness of autumn.
The weather in Toronto changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Toronto and find detailed weather information for every month.
September and January present stark contrasts in weather conditions. In September, temperatures range from a mild 3°C (38°F) at their lowest to a warm 33°C (91°F) at their highest, with an average of 17°C (64°F). The month experiences about 58 mm (2.3 in) of precipitation spread over 8 days, and humidity hovers around 76%. In contrast, January is characterized by frigid temperatures, with lows plummeting to -25°C (-12°F) and highs only reaching up to 12°C (53°F), averaging -4°C (25°F). This winter month sees slightly more precipitation at 62 mm (2.5 in) over the same number of days and higher humidity at 91%. For a detailed look at <a href="/weather/canada/ontario/toronto-january.html">Toronto weather in January</a>, check out the provided link.
Comparing the weather in September and February reveals a striking contrast in temperature and conditions. September boasts a mild average temperature of 17°C (64°F), with highs reaching up to 33°C (91°F), making it a pleasantly warm month. In contrast, February is much colder, with an average temperature of -3°C (26°F) and lows plummeting to -23°C (-9°F). While September experiences a moderate level of precipitation at 58 mm (2.3 in) over about 8 days, February sees a slightly higher precipitation total of 65 mm (2.6 in) spread over 12 days, along with higher humidity levels at 91%. For a more detailed look at February's conditions, check out Toronto weather in February.
September and March present stark contrasts in weather conditions. In September, temperatures range from a chilly 3°C (38°F) at night to a warm 33°C (91°F) during the day, with an average of 17°C (64°F). The month experiences about 58 mm (2.3 in) of precipitation over 8 days, accompanied by a humidity level of 76%. In contrast, March is much colder, with a minimum temperature plunging to -20°C (-4°F) and an average of 0°C (33°F), peaking at 19°C (66°F). It also receives similar precipitation of 58 mm (2.3 in) but experiences this over 9 days, and the humidity is higher at 88%. For more detailed insights, check out Toronto weather in March.
When comparing the weather in September and April, it's clear that September generally offers warmer temperatures. The average temperature in September reaches 17°C (64°F), with maximums of up to 33°C (91°F), whereas April's average is significantly cooler at 6°C (43°F), peaking at 22°C (72°F). Additionally, while September experiences 58 mm (2.3 in) of precipitation over about 8 days, April is wetter, with 98 mm (3.9 in) falling across 13 days. Humidity levels are also higher in April at 88%, compared to September's 76%. For a more detailed look at April's weather, visit Toronto weather in April.
In comparing the weather of September and May, we observe notable differences in temperature and precipitation patterns. September experiences a wider temperature range, with minimums dipping to 3°C (38°F) and maximums reaching up to 33°C (91°F), resulting in an average of 17°C (64°F). In contrast, May starts with chillier nights, with minimum temperatures around -3°C (28°F) and a more moderate average of 13°C (55°F), peaking at 30°C (86°F). Precipitation levels are higher in May, totaling 90 mm (3.6 in) over 11 days, while September records 58 mm (2.3 in) across 8 days. Additionally, May has slightly higher humidity at 82% compared to September’s 76%. For a more detailed look at the weather during this month, visit Toronto weather in May.
When comparing the weather in September and June, we see some notable differences. September boasts an average temperature of 17°C (64°F), with highs reaching up to 33°C (91°F), while June has a slightly warmer average of 19°C (66°F) and a maximum temperature of 31°C (89°F). Both months experience a minimum temperature of 3°C (38°F), indicating cooler nights. In terms of precipitation, September records 58 mm (2.3 in) over 8 days, while June has a higher precipitation level of 79 mm (3.1 in) across 10 days. Humidity levels are also comparable, with September at 76% and June slightly higher at 79%. For more detailed insights, you can check Toronto weather in June.
When comparing the weather in September and July, several notable differences emerge. In September, temperatures range from a minimum of 3°C (38°F) to a maximum of 33°C (91°F), with an average of 17°C (64°F), indicating a gradual transition into cooler autumn weather. In contrast, July features warmer conditions, with a minimum of 11°C (52°F), an average of 22°C (72°F), and a peak of 34°C (93°F). Precipitation in September is slightly lower at 58 mm (2.3 in) over 8 days, compared to July’s 78 mm (3.1 in) over 11 days, suggesting that July tends to be wetter. Both months exhibit similar humidity levels, with September at 76% and July at 77%. For more detailed information about July weather, you can visit Toronto weather in July.
September's weather contrasts with August in several notable ways. Although both months can reach similar maximum temperatures of around 33°C (91°F), September begins with cooler minimum temperatures, dropping to 3°C (38°F), compared to August's minimum of 9°C (48°F). The average temperature in September is also cooler at 17°C (64°F) against August's average of 21°C (71°F). Rainfall is slightly less in September, with 58 mm (2.3 in) over 8 days, compared to August's 78 mm (3.1 in) of precipitation across 12 days. Additionally, humidity is a bit higher in September at 76%, compared to 72% in August. For a more detailed look at the weather patterns, you can check out Toronto weather in August.
September and October bring notable differences in weather. September maintains a warmer atmosphere with average temperatures around 17°C (64°F) and maximums reaching up to 33°C (91°F), whereas October experiences cooler temperatures, averaging 11°C (52°F) and dipping to a minimum of -2°C (29°F). Precipitation also increases in October, with a total of 95 mm (3.7 in) over 13 days, compared to 58 mm (2.3 in) over 8 days in September. Additionally, humidity rises slightly in October to 83%, making the air feel more damp. For detailed insights, check out the Toronto weather in October.
September and November offer stark contrasts in weather. In September, temperatures range from a pleasant minimum of 3°C (38°F) to a warm maximum of 33°C (91°F), with an average of 17°C (64°F). The month sees about 58 mm (2.3 in) of precipitation over approximately 8 days and a relative humidity of 76%. In contrast, November brings much cooler temperatures, with a minimum dipping to -15°C (5°F) and an average of just 3°C (38°F), while the maximum reaches 22°C (72°F). Precipitation increases slightly to 72 mm (2.8 in) over around 10 days, accompanied by higher humidity at 88%. For more detailed information, you can check Toronto weather in November.
In September, temperatures in Toronto range from a mild 3°C (38°F) to a warm high of 33°C (91°F), with an average of 17°C (64°F). The month typically sees 58 mm (2.3 in) of precipitation over about 8 days, accompanied by a humidity level of 76%. In contrast, December brings a stark change in weather, with temperatures dipping significantly lower, ranging from a frigid -24°C (-11°F) to a maximum of 16°C (61°F) and averaging -1°C (31°F). This month records slightly higher precipitation at 70 mm (2.8 in) over 12 days, along with increased humidity at 87%. For more detailed information, you can check Toronto weather in December.
September in Toronto is a month of transition, as the sweltering summer heat gives way to cooler autumn breezes. With maximum temperatures soaring up to 33°C and an average drop to 17°C, the weather feels more comfortable, yet still pleasantly warm for outdoor activities. As rain makes an appearance on about eight days, the city can experience unexpected showers, contributing to the humidity level of 76% that adds a hint of mugginess to the early part of the month. This blend of warm days and cooler nights makes September a unique period compared to the hotter summer months. For those looking to understand the broader patterns, detailed insights can be found at Toronto Climate.