Last updated: April 22, 2025
In September, the weather in Saint John, Canada offers a delightful transition from summer to fall. With a maximum temperature reaching 22°C (73°F) and an average of 15°C (59°F), the month provides pleasant days for outdoor activities. However, the minimum temperature can drop to 7°C (45°F), reminding residents of the approaching cooler season. Rainfall is a notable feature this month, with 108 mm (4.3 in) of precipitation over approximately 10 days, contributing to a humidity level of 82%. This combination of moderate warmth and frequent showers creates a vibrant, refreshing atmosphere perfect for enjoying the natural beauty of the region.
September in Saint John, Canada, marks a transition into the gentle embrace of autumn. With temperatures ranging from a minimum of 7°C (45°F) to a maximum of 22°C (73°F), this month showcases a pleasant average of 15°C (59°F), offering a refreshing respite after the warmer summer months. As the vibrant hues of fall begin to emerge, the evenings grow cooler, inviting sweaters and warm drinks. This shift in weather is a clear indication that summer's warmth is giving way to the crisp, invigorating air of early autumn, making it a lovely time for outdoor adventures amidst the stunning fall foliage.
In September, Saint John experiences a notable shift in precipitation, with an average of 108 mm (4.3 in) falling over 10 days. This marks a slight increase from the dry summer months of July and August, where rainfall was just 92 mm (3.6 in) and 89 mm (3.5 in), respectively. As the city transitions into autumn, the precipitation levels start to mirror the wetter months ahead, foreshadowing October’s average of 123 mm (4.8 in). This trend indicates a gradual buildup of moisture, preparing the region for the more substantial rainfall that arrives in November, typically the wettest month of the year. With days still warm but increasingly mixed with rain, September serves as a bridge between summer’s dryness and the approaching winter conditions.
As summer transitions into fall, September in Saint John, Canada, experiences a notable consistency in humidity, averaging around 82%. This figure aligns closely with the preceding months, particularly August and June, where levels hovered between 82% and 84%. Amidst the lush greenery of late summer, the humidity begins to taper off slightly compared to the winter months, which see higher averages, such as 84% in February and November. The gradual decline from the peak summer humidity creates a refreshing atmosphere, making September a comfortable time for residents and visitors alike to enjoy the emerging autumn landscape.
As September rolls into Saint John, Canada, the UV Index reflects the transition toward autumn with a high rating of 7, translating to a burn time of 25 minutes for sensitive skin. This month marks a slight dip from the very high indices of summer, where intense sunlight peaked at 10 in June and remained elevated through August. Despite the reduction, it's crucial to remain vigilant about sun protection, especially as UV levels can still pose risks. Interestingly, the UV Index has shown a gradual decline since its July peak, settling now alongside the high exposures of April. For those exploring the area, don't forget to check the complete details of the UV Index to stay safe under the sun: Saint John UV Index.
UV Risk Categories
September in Saint John, Canada, marks a delightful transition as summer lingers into early autumn, bringing 266 hours of sunshine. This month enjoys a substantial amount of daylight, following a vibrant August that boasts 312 hours—the sun's peak performance. As the seasons shift, September's sunshine still offers a generous glow, although slightly less than the lush summer months. Compared to earlier months, such as June and July, which hover around 307 and 304 hours, the sunlight in September gently begins to recede, paving the way for the early hints of fall. This trend reveals how Saint John's hours of sunshine gracefully ebb, setting a cozy tone for the approach of October, which brings 222 hours. Embracing these sunlit moments, residents and visitors alike can savor the beauty of a Saint John September, where lingering warmth intertwines with the promise of autumn's arrival.
September in Saint John, Canada, offers a refreshing shift in weather patterns, with a 42% chance of sunny days. This marks a notable increase compared to the summer months, where July sees a mere 19% and August a 29%, followed by a steady rise as we transition into fall. The chances for sunshine in September are higher than in several preceding months, showcasing a delightful blend of warmth and light before the chill of autumn sets in. As the cooler air approaches, this brief window of sunny weather provides a perfect opportunity for outdoor adventures, making September an enticing time to enjoy the natural beauty of the region.
As summer fades into autumn, September in Saint John, Canada, offers a gentle transition with 12 hours of daylight. Following the sun-soaked days of July and August, which each basked in 15 hours of light, September marks the beginning of shorter days. This gradual decline parallels the onset of fall, reminiscent of April's promise of longer days with 13 hours of sunlight. As daylight dwindles heading into October and November, where the hours slip back to 10 and 9 respectively, the rhythm of the changing seasons becomes apparent. The data reflects not only the waning daylight but also invites a moment to embrace the cozy charm of autumn evenings in this picturesque coast town.
As September ushers in the transition to autumn in Saint John, Canada, the average wind speed settles at a gentle 4.6 m/s (10 mph). This marks a slight increase from the languid summer months, where winds dipped to their lowest, averaging just 4.0 m/s (9 mph) in August. The subtle rise in September wind reflects the changing season, as nature begins to stir with a crisper energy. Comparing this to the earlier months of the year, the winds were notably brisker during winter and spring, with January and March recording averages of around 5.5 m/s (12 mph) and 6.2 m/s (14 mph), respectively. As the year progresses toward October and November, we can expect the winds to pick up again, hinting at the dynamic interplay between the vibrant autumn leaves and the refreshing, invigorating air.
The weather in Saint John 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 Saint John and find detailed weather information for every month.
September and January present strikingly different weather conditions in Saint John. In September, temperatures range from a mild 7°C (45°F) to a pleasant 22°C (73°F), with an average of 15°C (59°F) and a high humidity level of 82%. The month experiences about 108 mm (4.3 in) of precipitation over approximately 10 days. In stark contrast, January brings frigid temperatures, with a minimum of -22°C (-8°F) and a maximum of just 13°C (56°F), averaging -4°C (26°F), alongside a comparable precipitation level of 107 mm (4.2 in) over 10 days. The humidity remains high at 83%, contributing to the biting cold that characterizes the heart of winter. For a deeper dive into what to expect, check out Saint John weather in January.
September and February present strikingly different weather patterns. In September, temperatures typically range from a cool 7°C (45°F) to a comfortable high of 22°C (73°F), with an average of 15°C (59°F). This month experiences about 108 mm (4.3 in) of precipitation over approximately 10 days, along with a humidity level of 82%. In contrast, February plunges into the colder months, where temperatures can drop as low as -20°C (-4°F) and rarely peak above 10°C (50°F), averaging around -3°C (26°F). The precipitation increases slightly to 112 mm (4.4 in) across about 12 days, while humidity remains at a high 84%. For more detailed insights on February weather, check out Saint John weather in February.
September and March exhibit notably different weather patterns in Saint John. In September, temperatures range from a minimum of 7°C (45°F) to an average of 15°C (59°F), peaking at 22°C (73°F), while March experiences much colder conditions with a minimum of -17°C (2°F) and an average of -1°C (31°F), reaching a maximum of 11°C (52°F). While precipitation totals are somewhat similar—with September receiving 108 mm (4.3 in) and March 88 mm (3.5 in)—the feel of the months differs significantly, with September's humidity at 82% creating a warm, late-summer ambiance, contrasting sharply with March's cold and crisp air. For more detailed insights on March's weather, visit Saint John weather in March.
When comparing the weather in September and April, notable differences arise in temperature and precipitation patterns. September boasts a more moderate climate with average temperatures ranging from a chilly 7°C (45°F) at night to a comfortable 22°C (73°F) during the day, whereas April experiences cooler conditions with temperatures typically ranging from a minimum of -5°C (23°F) to a maximum of 13°C (55°F). In terms of precipitation, both months receive significant rainfall, but April is slightly wetter, averaging 129 mm (5.1 in) over 13 days compared to September's 108 mm (4.3 in) spread across 10 days. Humidity levels are quite similar, with September at 82% and April at 80%. For a detailed look at the weather specifics for April, you can check out Saint John weather in April.
September and May present distinct weather patterns, with September generally being warmer and more humid. In September, temperatures range from a minimum of 7°C (45°F) to a maximum of 22°C (73°F), with an average of 15°C (59°F) and humidity levels at 82%. In contrast, May sees cooler temperatures, with a minimum of 1°C (33°F) and a maximum of 20°C (68°F), averaging 9°C (48°F), accompanied by slightly lower humidity at 78%. Both months experience significant rainfall, with September receiving 108 mm (4.3 in) over about 10 days, while May sees a bit more precipitation at 117 mm (4.6 in) over 12 days. For those interested in more detailed information, check out Saint John weather in May.
When comparing the weather in September and June, we see some interesting similarities and differences. September features slightly warmer temperatures, with a minimum of 7°C (45°F) and an average of 15°C (59°F), compared to June's minimum of 4°C (39°F) and an average of 13°C (56°F). Both months experience comparable maximum temperatures, with September reaching up to 22°C (73°F) and June hitting a maximum of 21°C (71°F). Precipitation levels are fairly similar, with September receiving 108 mm (4.3 in) over 10 days and June just slightly higher at 110 mm (4.3 in) over 11 days. Humidity remains constant at 82% in both months. For a more detailed look at June's climate, you can check out Saint John weather in June.
In comparing the weather between September and July, we see noticeable differences in temperature and precipitation. September experiences a wider temperature range, with a minimum of 7°C (45°F) and a maximum of 22°C (73°F), while July's temperatures typically hover between a minimum of 11°C (51°F) and the same maximum of 22°C (72°F). This results in a slightly cooler average temperature of 15°C (59°F) in September compared to July's average of 16°C (62°F). Additionally, September sees more precipitation with 108 mm (4.3 in) spread over 10 days, while July records 92 mm (3.6 in) over 13 days. Humidity levels are relatively similar, but slightly higher in July at 84% compared to September's 82%. For further details, you can check out Saint John weather in July.
In comparing the weather of September to August, we notice a shift towards cooler temperatures and increased precipitation. September's minimum temperature drops to 7°C (45°F), compared to August's milder 11°C (53°F), while the average temperature in September is slightly lower at 15°C (59°F) versus 17°C (63°F) in August. Despite having the same number of rainy days, September experiences a higher total precipitation of 108 mm (4.3 in) compared to August's 89 mm (3.5 in). Humidity remains consistent at 82% for both months, contributing to a noticeably cooler and wetter September. For more detailed weather information, you can refer to Saint John weather in August.
In September, temperatures typically range from a minimum of 7°C (45°F) to a maximum of 22°C (73°F), with an average of 15°C (59°F). The month experiences about 108 mm (4.3 in) of precipitation spread over 10 days, accompanied by a consistent humidity of 82%. In contrast, October ushers in cooler temperatures, with a minimum of 0°C (33°F) and an average of 11°C (52°F), peaking at 19°C (67°F). Precipitation increases slightly to 123 mm (4.8 in) over 12 days, maintaining the same humidity level of 82%. For more detailed information on October weather, check out Saint John weather in October.
September and November exhibit contrasting weather patterns. In September, temperatures average around 15°C (59°F), with a minimum of 7°C (45°F) and a maximum of 22°C (73°F), while November’s average drops significantly to 5°C (40°F), with a minimum of -12°C (10°F). Precipitation is also more intense in November, accumulating to 184 mm (7.3 in) over 14 days compared to September's 108 mm (4.3 in) across 10 days. The humidity in both months remains relatively high, with September at 82% and November slightly higher at 84%. For more detailed insights, you can check Saint John weather in November.
In September, Saint John experiences milder weather, with temperatures ranging from a minimum of 7°C (45°F) to a maximum of 22°C (73°F) and an average of 15°C (59°F). The month sees about 108 mm (4.3 in) of precipitation over approximately 10 days, accompanied by a consistent humidity of 82%. In contrast, December ushers in much colder conditions, with temperatures dipping significantly lower, ranging from a minimum of -18°C (-1°F) to a maximum of 14°C (57°F) and averaging -1°C (31°F). Precipitation increases to 142 mm (5.6 in) over 12 days, while humidity remains steady at 82%. For more detailed information, you can refer to Saint John weather in December.
As September rolls in, Saint John experiences a delightful transition into autumn, setting itself apart from the warmer months of summer. With an average temperature hovering around a comfortable 15°C (59°F), it invites sweater weather without the biting cold of winter just yet. Although the days are still mild, the increased humidity at 82% alongside 108 mm of precipitation over 10 days indicates the gradual shift towards wetter conditions typical of the fall season. This month encapsulates the beauty of changing leaves and the gentle arrival of cooler breezes, making it a charming time to explore the city. For more details about the weather throughout the year, visit Saint John Climate.