Last updated: April 22, 2025
In September, Calgary, Canada experiences a diverse range of temperatures, with highs reaching up to 33°C (92°F) and lows dipping to -3°C (27°F). The month boasts an average temperature of 11°C (52°F), providing a transitional feel as summer fades. Rainfall is moderate, with a total of 43 mm (1.7 in) accumulated over 9 days, while humidity levels hover around 74%, enhancing the crispness of early autumn air. This blend of conditions results in a dynamic climate, showcasing Calgary's unique weather patterns as the seasons change.
As September rolls into Calgary, the city begins to experience a noticeable transition in temperatures, with minimums dropping to -3°C (27°F) and average highs reaching a comfortable 33°C (92°F). This month marks a departure from the sweltering summer, showcasing a blend of cool nights and pleasantly warm days, where daytime averages settle around 11°C (52°F). The contrast with the preceding months is clear, as September cushions the approach of fall, inviting residents and visitors alike to savor the mildness before the chill of autumn sets in. It's a time when the crispness of the air mingles with the lingering warmth of summer, making Calgary an ideal place for outdoor adventures against the backdrop of a stunning autumn landscape.
September in Calgary brings a notable transition as summer gently gives way to fall. With 43 mm (1.7 in) of precipitation spread over 9 days, the month mirrors August in its rainfall but marks a critical pivot in the season. The city experiences a steady rhythm of light showers, setting the stage for the cooler months ahead. Notably, this consistent moisture helps maintain lush landscapes, even as trees begin to don their autumn hues. The month stands at a crucial intersection, balancing the remnants of summer's warmth while hinting at the crispness of the approaching autumn.
As summer fades into fall, September in Calgary reveals a noticeable dip in humidity, with levels falling to 74%—the lowest point since early in the year. This decline reflects a broader trend of decreasing humidity throughout the summer months, where figures hovered between 77% and 80% from June to August. The transition into autumn signals a shift, with October experiencing a slight rebound to 80%. This rhythmic pattern, where summer air is gradually replaced by the crispness of fall, provides a refreshing change for residents and visitors alike, as they prepare for the cooler months ahead. Overall, September stands out as a pivotal month, bridging the warm, humid days of summer with the increasingly brisk air of autumn.
As the summer sun slows its intensity in September, Calgary experiences a UV Index of 7, categorizing the exposure as high. This marks a slight decrease from the sweltering peaks of July and August, reflective of the transition into fall. With a recommended burn time of 25 minutes, it's clear that while the risk of overexposure diminishes compared to the height of summer, caution is still necessary. Interestingly, the trend shows a gradual decline in the UV Index from the blazing 9 in July to a more manageable 7 in September, indicating that while outdoor enthusiasts can still enjoy the lingering warmth, vigilance in sun protection remains vital. For more detailed insights, check out the Calgary UV Index.
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September in Calgary brings a delightful transition from the long summer days, with 255 hours of sunshine to enjoy. This month typically sees a gradual decline in daylight, reflecting the shift towards autumn as daylight hours drop from the abundant sunshine of summer, peaking at 382 hours in July. While September's sunlight is less than August’s 331 hours, it's still a generous offering compared to earlier months like January and February, where the cold, dark days linger with just 140 and 180 hours respectively. The trend showcases a seasonal ebb and flow, making September a picturesque time to embrace the mild weather and golden hues of fall in this vibrant city.
In Calgary, September carries a 47% chance of sunny weather, which aligns closely with the summer's mixed patterns. As we transition from the warmth of July and August—when sunny days peak at 57% and 47% respectively—the likelihood remains fairly stable, reflecting the gradual shift towards autumn. This steady forecast suggests that while September may not boast the brightest skies of the year, it still offers a fair share of pleasant days, making it an ideal time for outdoor activities amid the beautiful fall foliage. With the sun's presence lingering before the cooler months set in, residents and visitors alike can still savor the last rays of summer in this vibrant city.
As summer wanes into autumn, September in Calgary greets residents with approximately 12 hours of daylight, a gentle decline from the sun-soaked 16 hours enjoyed in June. This month marks a transition, where daylight gradually recedes and shadows lengthen. Following a peak in brightness during the height of summer, the daylight hours begin to dip, echoing the city's rhythmic shift from the vibrant energy of May and June to the softer hues of fall. While the brightness starts to fade, the crisp September air invites outdoor activities, making it a perfect time to embrace the changing seasons before winter takes hold.
As September unfolds in Calgary, the winds begin to whisper a gentle farewell to summer, with an average speed of 2.7 m/s (6 mph). This slight dip in velocity from the warmer months contrasts with the steadier breezes of spring and early summer, reflecting a seasonal transition. Following July's calm, where winds slowed to 2.4 m/s (5 mph), September's gusts regain some vigor but remain relatively mild, preparing the city for the brisk air of autumn. This subtle shift not only marks a change in weather but also a fresh breath of air, inviting Calgarians to embrace the beauty of the season ahead.
The weather in Calgary 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 Calgary and find detailed weather information for every month.
In comparing the weather of September and January, there is a drastic shift in temperature and conditions. September experiences a much wider temperature range, with minimums dropping to -3°C (27°F) and maximums peaking at a warm 33°C (92°F), averaging around 11°C (52°F). In stark contrast, January sees chilling temperatures, with lows plunging to a frigid -36°C (-32°F) and an average of -7°C (20°F), making it one of the coldest months of the year. Additionally, September brings 43 mm of precipitation over 9 days, while January is much drier, with only 8 mm over just 2 days. However, January also has a higher humidity level at 91%, compared to September's 74%. For more detailed information on January weather, visit Calgary weather in January.
In September, Calgary experiences a more moderate climate with temperatures ranging from a minimum of -3°C (27°F) to a maximum of 33°C (92°F) and an average of 11°C (52°F). This month sees around 43 mm (1.7 in) of precipitation over 9 days and a humidity level of 74%. In stark contrast, February is much colder, featuring temperatures that plummet to a minimum of -35°C (-31°F) and a maximum of 13°C (56°F), with an average temperature of -10°C (14°F). Despite its lower precipitation at 29 mm (1.2 in) across 8 days, February's humidity is notably higher at 93%. For more detailed information on the winter conditions, you can check Calgary weather in February.
September and March present distinctly contrasting weather conditions. In September, temperatures range from a chilly -3°C (27°F) at night to a warm 33°C (92°F) during the day, with an average of 11°C (52°F). This month experiences a moderate amount of precipitation at 43 mm (1.7 in) over 9 days, coupled with a humidity level of 74%. In contrast, March is much colder, with temperatures plummeting to a minimum of -31°C (-23°F) and only reaching a maximum of 18°C (64°F), resulting in an average temperature of -3°C (27°F). The precipitation is lower at 27 mm (1.1 in) over 6 days, yet humidity is higher at 88%. For a closer look at March weather specifics, visit Calgary weather in March.
In comparing the weather of September and April, we notice significant differences in temperatures and humidity levels. September typically experiences milder temperatures, ranging from a chilly minimum of -3°C (27°F) to a warm maximum of 33°C (92°F), with an average of 11°C (52°F). In contrast, April starts off much colder, with minimum temperatures plummeting to -17°C (1°F) and an average of only 3°C (37°F), while it peaks at a more moderate 26°C (80°F). Both months receive similar amounts of precipitation, around 43 mm (1.7 in) for September and 38 mm (1.5 in) for April, spread over about nine days each. However, April tends to be more humid, with humidity levels reaching 84% compared to September's 74%. For more detailed weather insights, you can check Calgary weather in April.
In comparing the weather of September and May, we observe notable differences in temperature and precipitation. September boasts a wider range of temperatures, with a minimum of -3°C (27°F) and a maximum of 33°C (92°F), averaging around 11°C (52°F). In contrast, May experiences slightly cooler temperatures, with a minimum of -6°C (22°F) and a maximum of 29°C (85°F), averaging 10°C (51°F). Precipitation is also a factor, as September receives 43 mm (1.7 in) over about 9 days, while May sees a higher total of 62 mm (2.4 in) spread across 10 days. Additionally, May has a higher humidity level of 80%, compared to September's 74%. For more detailed information, you can check Calgary weather in May.
In comparing the weather of September and June, we find notable differences in temperature and precipitation patterns. September experiences a broader temperature range, with lows of -3°C (27°F) and highs reaching up to 33°C (92°F), while June maintains milder conditions with minimum temperatures of 1°C (35°F) and maximums of 37°C (99°F). Although June has higher humidity at 79% compared to September's 74%, it also records increased precipitation, with 85 mm (3.3 in) over 12 days compared to September's 43 mm (1.7 in) across 9 days. For a closer look at June's weather, visit Calgary weather in June.
In comparing the weather of September and July, we observe notable differences in temperature and precipitation. September experiences a broader temperature range, with minimums dipping to -3°C (27°F) and maximums reaching up to 33°C (92°F), resulting in an average of 11°C (52°F). In contrast, July boasts milder temperatures, with a minimum of 5°C (41°F), an average of 17°C (63°F), and a maximum of 36°C (98°F). When it comes to precipitation, July typically sees more rainfall at 69 mm (2.7 in) over 11 days, whereas September has less at 43 mm (1.7 in) across 9 days. Additionally, July's humidity is slightly higher at 80%, compared to September's 74%. For more specifics on July weather, you can check Calgary weather in July.
Comparing the weather of September to that of August reveals notable differences in temperature and humidity. In September, temperatures range from a minimum of -3°C (27°F) to a maximum of 33°C (92°F), with an average temperature of 11°C (52°F). In contrast, August experiences a milder range, with the minimum at 3°C (37°F) and a maximum of 38°C (100°F), averaging 16°C (62°F). Both months receive similar amounts of precipitation at 43 mm (1.7 in), but September experiences rain over 9 days compared to 7 days in August. Additionally, September has a slightly lower humidity level at 74%, while August sits at 77%. For a more detailed look at August weather, check out Calgary weather in August.
In September, temperatures exhibit a wide range, with lows around -3°C (27°F) and highs reaching up to 33°C (92°F), resulting in an average of 11°C (52°F). The month experiences approximately 43 mm (1.7 in) of precipitation over 9 days, with humidity levels at 74%. In contrast, October brings a significant drop in temperatures, with minimums plunging to -22°C (-8°F) and an average of just 4°C (39°F), while the maximums peak at 24°C (75°F). Precipitation decreases to 31 mm (1.2 in) over only 5 days, and humidity rises slightly to 80%. For a detailed look at the weather conditions, you can check out Calgary weather in October.
September and November present quite a contrast in weather patterns. In September, temperatures can range from a chilly -3°C (27°F) at night to a warm 33°C (92°F) during the day, with an average of 11°C (52°F). This month experiences moderate precipitation of 43 mm (1.7 in) over about 9 days, accompanied by a humidity level of 74%. In contrast, November brings much colder temperatures, with nighttime lows plummeting to -23°C (-9°F) and daytime highs reaching only 21°C (70°F), averaging -2°C (29°F). Precipitation decreases to 26 mm (1.0 in) over 7 days, but the humidity rises significantly to 86%. For more details on what to expect this time of year, visit Calgary weather in November.
September and December present stark contrasts in weather patterns. In September, temperatures range from a crisp minimum of -3°C (27°F) to a warm maximum of 33°C (92°F), with an average of 11°C (52°F). The month experiences a relatively moderate level of precipitation at 43 mm (1.7 in) across about 9 days, coupled with a humidity level of 74%. In contrast, December sees much colder temperatures, with a minimum plummeting to -35°C (-31°F) and an average of -7°C (20°F), reaching a maximum of just 14°C (58°F). Precipitation decreases to 24 mm (0.9 in) over only 5 days, while humidity rises significantly to 92%. For more detailed information, you can check Calgary weather in December.
As summer gives way to autumn, September in Calgary showcases a remarkable transition in weather. With daytime temperatures peaking at a warm 33°C, the month often retains the lingering warmth of summer, yet it cools significantly at night, averaging around 11°C. This variability creates a unique backdrop, as the chilly mornings could surprise those unprepared for the sudden shifts. However, the month is also marked by increased precipitation, with 43 mm falling over about 9 days, adding to the already significant humidity of 74%. This contrasts with the drier, warmer spells of July and August, making September a month of change and adaptation in Calgary’s climate. For more insights, visit Calgary Climate.