September Weather in Bangor, United Kingdom

Last updated: March 17, 2025

In Bangor, United Kingdom, September brings a mix of mild temperatures and frequent rain. The maximum daily temperature can reach up to 20°C (68°F), while the average hovers around 13°C (56°F), and lows dip to a refreshing 8°C (46°F). With an impressive 95 mm (3.8 in) of precipitation over 17 days, this month contributes to the lush greenery that characterizes the region. Coupled with a humidity level of 88%, the weather can feel quite damp, making it a quintessentially autumnal experience.

September Temperature in Bangor

As September rolls in, Bangor, United Kingdom, experiences a gentle transition towards autumn, marked by a notable drop in temperatures compared to the summer months. This month sees minimums around 8°C (46°F), while the average temperature hovers at a comfortable 13°C (56°F) and can peak at 20°C (68°F). The shift from late summer warmth to cooler days is evident, but the milder conditions provide a pleasant backdrop for outdoor activities. As the days gradually shorten, the crisp air invites locals and visitors alike to embrace the scenic beauty of the region, making September a delightful time to enjoy Bangor’s landscapes before the chill of winter settles in.

September Weather in Bangor: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Bangor, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec434344465055575856524845
Data source: Temperature data for Bangor generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Bangor

In September, Bangor experiences a notable balance in precipitation, with 95 mm (3.8 in) of rain falling over 17 days. This marks a slight decrease from the previous month's August, which recorded the highest rainfall of the year at 129 mm (5.1 in) over 19 days. The shift signals the gradual transition from the wetter summer months to the more varied conditions of autumn, as September tends to deliver more stable weather patterns compared to the increased drizzle typical of the late summer. While rainfall remains substantial, it reflects a trend of decreasing levels compared to the peak summer months, allowing for glimpses of dry spells amidst the refreshing rains. As Bangor heads deeper into autumn, the days grow shorter and the likelihood of rain continues to rise, hinting at an impending seasonal shift.

September Precipitation Trends in Bangor

The chart displays monthly precipitation patterns in Bangor, with values for each month alongside September's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec781119445699310812995125129118
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Bangor

In September, Bangor experiences a notable uptick in humidity, reaching 88%, which is one of the highest levels for the year. This increase marks a shift from the relatively stable humidity levels seen during the summer months, where values hovered around 86%. As autumn approaches, the gradual rise in humidity foreshadows the wetter conditions of the coming months, with October and November typically presenting even higher averages at 89% and 90%, respectively. Overall, the trend suggests that Bangor's late summer and early autumn months are characterized by a noticeable boost in moisture in the air, setting the stage for the rainy season ahead.

September Average Humidity in Bangor

This chart illustrates the average monthly humidity levels in Bangor, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec87%86%86%85%82%84%86%86%88%89%90%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Bangor

As September arrives in Bangor, the UV Index reflects a moderate level of sun exposure with a reading of 5. This indicates a slight dip from the previous summer months where levels reached a peak of 8, marking very high exposure from June to July. As we transition into autumn, the burn time increases slightly to 30 minutes, reminding us to stay sun-safe even as the temperatures cool. Overall, the trend in Bangor's UV Index this month suggests that while the intensity of UV radiation begins to wane, caution is still warranted when enjoying outdoor activities. For more detailed information, visit the Bangor UV Index.

Maximum UV Index Levels in Bangor for September

The chart shows the monthly maximum UV Index (UVI) for Bangor in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec123568865321
Data source: Bangor September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Bangor

As summer gives way to autumn, September in Bangor, United Kingdom, offers a delightful retreat with a generous 302 hours of sunshine. This marks a gradual decline from the sun-drenched heights of July and August, where the city basked in 415 and 361 hours respectively. The transition is marked by a vibrant spell of warm days, enticing nature lovers to explore the burgeoning landscapes. Although September’s sunshine foreshadows the shorter days of October, it still holds its charm, providing a perfect backdrop for enjoying the beautiful turning leaves. As the year progresses, the gradual tapering of sunlight hints at the impending cozy embrace of autumn, leading us into the cooler months ahead.

Monthly Sunshine Duration in Bangor: September Highlighted

The September sunshine duration represents the total number of hours Bangor experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec82h153h221h334h413h409h415h361h302h233h120h90h
Data source: Bangor September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Bangor During September

In Bangor, United Kingdom, the likelihood of sunny weather takes a noticeable dip as summer transitions into autumn. September, with its 22% chance of sunshine, mirrors the trend seen in August and hints at a gradual retreat from the brighter days of the year. Compared to the relatively sunnier spring months, such as April with 48%, and the peaks of summer, the sun becomes more elusive as days shorten. This decline continues into the fall, with October and November dropping to 19% and 19% respectively. Consequently, while September may still offer some pleasant sunny spells, it marks the beginning of a cooler, cloudier season in Bangor.

Percentage of Sunny Days in September in Bangor

The chart illustrates the percentage of sunny days in Bangor throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Bangor experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec26%25%21%48%34%25%34%22%22%19%19%15%
Data source: Bangor September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Bangor in September

As summer fades, September in Bangor, United Kingdom, brings a gentle transition into autumn with approximately 12 hours of daylight. This marks a noticeable decline from the sun-soaked heights of June, which boasted an impressive 17 hours. The month finds a sweet spot, balancing the lingering warmth of early fall against the encroaching darkness of winter. Following the vibrant 16 hours of daylight in May and July, September gradually shifts towards the shorter, cozier days of October with just 10 hours of light. This subtle reduction in daylight not only signifies the changing seasons but also enhances the beauty of Bangor's landscape as colors transform, inviting moments of reflection in the diminishing light.

Average Daylight Hours in Bangor for September

The chart illustrates the variation in daylight duration in Bangor throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h 52m9h 42m11h 54m14h 9m16h 9m17h 13m16h 38m14h 49m12h 39m10h 25m8h 23m7h 17m
Data source: Bangor daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Bangor

As September rolls into Bangor, the winds begin to shift from the tranquil breezes of summer to a slightly brisker pace. With an average wind speed of 4.2 m/s (9 mph), September maintains a gentle yet refreshing ambiance, creating an inviting atmosphere for outdoor activities. This modest increase from the quieter summer months reflects a gradual transition towards the autumnal gusts that follow. Interestingly, the wind speeds experienced earlier in the year, particularly in February with its peak of 8.4 m/s (19 mph), seem a distant memory as the region prepares for the cooler months ahead. The steady progression from 4.6 m/s in April through the summer to this September's winds subtly hints at the evolving force of nature, reminding us that change is always in the air.

Average September Wind Speed in Bangor

The chart displays monthly wind speed patterns in Bangor, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec6.08.46.04.65.24.93.43.94.2 m/s6.16.96.6
Data source: Bangor September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Bangor Compares to Other Months

The weather in Bangor 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 Bangor and find detailed weather information for every month.

In comparing the weather between September and January, September offers milder temperatures, with an average of 13°C (56°F), ranging from a minimum of 8°C (46°F) to a maximum of 20°C (68°F). This month experiences higher precipitation, totaling 95 mm (3.8 in) over 17 days, paired with relatively high humidity at 88%. In contrast, January is much cooler, with an average temperature of 6°C (44°F), a minimum of 1°C (33°F), and a maximum of 13°C (56°F). It sees less precipitation at 78 mm (3.1 in) across 14 days and slightly lower humidity at 87%. For a detailed look at the conditions in January, you can check out Bangor weather in January.

September and February exhibit distinct weather characteristics. In September, temperatures range from a mild minimum of 8°C (46°F) to a comfortable maximum of 20°C (68°F), with an average of 13°C (56°F). The month sees about 95 mm (3.8 in) of precipitation over 17 days and humidity levels around 88%. In contrast, February is notably cooler, with temperatures ranging from a minimum of 1°C (33°F) to a maximum of 12°C (54°F), averaging 6°C (43°F). The precipitation increases slightly to 111 mm (4.4 in) across 16 days, accompanied by a humidity level of 86%. For more detailed insights, you can refer to Bangor weather in February.

When comparing the weather in September and March, we observe notable differences in temperature and conditions. September experiences a milder climate, with average temperatures ranging from a minimum of 8°C (46°F) to a maximum of 20°C (68°F), whereas March is much cooler, with temperatures dipping to a minimum of -2°C (29°F) and reaching a maximum of 14°C (57°F). Both months have similar precipitation levels, around 95 mm (3.8 in) in September and 94 mm (3.7 in) in March, each with 17 days of rainfall. Humidity also remains high in both months, with September at 88% and March slightly lower at 86%. For more detailed information on March weather, you can check Bangor weather in March.

When comparing the weather in September and April, a notable difference can be observed. September typically enjoys milder temperatures, with an average of 13°C (56°F) and highs reaching up to 20°C (68°F), while April's temperatures are cooler, averaging around 8°C (47°F) and peaking at 14°C (58°F). Additionally, September experiences significantly more precipitation, with 95 mm (3.8 in) falling over 17 days, compared to April's 45 mm (1.8 in) across just 10 days of rain. Both months have high humidity levels, but September is slightly more humid at 88% compared to April's 85%. For more insights on April weather specifically, you can check out Bangor weather in April.

September and May both feature mild temperatures, but September tends to be warmer overall. In September, the minimum temperature hovers around 8°C (46°F), with an average of 13°C (56°F) and a maximum reaching 20°C (68°F). In contrast, May starts a bit cooler, with minimums of 4°C (40°F), an average of 10°C (51°F), and a maximum of 17°C (62°F). Additionally, September experiences more precipitation, totaling 95 mm (3.8 in) over 17 days, compared to May's 69 mm (2.7 in) over just 12 days. Humidity levels are also slightly higher in September at 88%, compared to 82% in May. For a closer look at May's weather specifics, check out Bangor weather in May.

In September, the weather tends to be slightly warmer compared to June, with average temperatures ranging from a minimum of 8°C (46°F) to a maximum of 20°C (68°F). The month experiences higher precipitation, with 95 mm (3.8 in) of rain over 17 days, and humidity levels are also elevated at 88%. In contrast, June features a comparable minimum temperature of 8°C (47°F) and an average maximum of 19°C (66°F), but with slightly less precipitation totaling 93 mm (3.7 in) over 15 days, and lower humidity at 84%. For a detailed overview, you can check Bangor weather in June.

When comparing the weather in September to that of July, both months exhibit mild temperatures, with July having slightly higher averages. September sees minimum temperatures of 8°C (46°F), an average of 13°C (56°F), and maximums reaching 20°C (68°F). In contrast, July's temperatures vary only slightly, with a minimum of 9°C (49°F), an average of 14°C (58°F), and a similar maximum of 20°C (69°F). Precipitation levels are also noteworthy; September receives approximately 95 mm (3.8 in) of rainfall over 17 days, while July experiences slightly more rain at 108 mm (4.2 in) over 15 days. Humidity is relatively high in both months, with September at 88% and July at 86%. For those interested in July's specific weather patterns, you can explore more at Bangor weather in July.

In comparing the weather of September and August, September experiences slightly cooler temperatures, with an average of 13°C (56°F) compared to August's 14°C (58°F). However, the minimum temperature in September is lower at 8°C (46°F), while August starts warmer at 10°C (51°F). Precipitation in September is less, totaling 95 mm (3.8 in) over 17 days, in contrast to August's higher 129 mm (5.1 in) across 19 days. Humidity remains comparable, with September at 88% and August at 86%. For further details on August weather, visit Bangor weather in August.

September and October present a noticeable shift in weather patterns. In September, temperatures range from a mild 8°C (46°F) at night to a comfortable average of 13°C (56°F) during the day, peaking at 20°C (68°F). However, with 95 mm (3.8 in) of rainfall over 17 days, the month experiences a fairly high level of precipitation. October, on the other hand, brings cooler temperatures, with nighttime lows of 5°C (41°F), an average temperature of 11°C (53°F), and maximums reaching only 17°C (63°F). This month also sees an increase in precipitation, totaling 125 mm (4.9 in) across 19 days, while humidity remains steady at 89%. For more detailed weather information, visit Bangor weather in October.

In September, the weather is generally milder, with average temperatures ranging from a minimum of 8°C (46°F) to a maximum of 20°C (68°F). While September sees considerable rainfall, totaling around 95 mm (3.8 in), it experiences slightly fewer rainy days compared to November. In contrast, November is cooler, with temperatures dipping to an average minimum of 3°C (38°F) and a maximum of 14°C (58°F). Precipitation increases in November, reaching 128 mm (5.1 in) over 21 days, and the humidity remains relatively high at 90%. For a specific look at weather trends during this month, check out Bangor weather in November.

In September, the weather typically features milder temperatures, with a minimum of 8°C and an average of 13°C, peaking at around 20°C. The month experiences approximately 95 mm of precipitation over 17 days, alongside a high humidity level of 88%. In contrast, December brings cooler conditions, with temperatures dropping to a minimum of 2°C and an average of 7°C, reaching a maximum of 13°C. Precipitation increases slightly to 118 mm and occurs over 18 days, while humidity remains relatively stable at 86%. For more details, check out Bangor weather in December.

Compare Bangor's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Bangor

As September unfolds in Bangor, the weather offers a refreshing transition from the warmth of summer, characterized by mild temperatures and higher humidity levels. Unlike the sweltering heat of July and August, this month sees cooler evenings and frequent rain, with about half of the days enjoying precipitation. The average temperature settles at a comfortable level, making outdoor activities pleasant despite the occasional downpour. As the month progresses, the lush greenery facilitated by the rainfall enhances the town’s scenic beauty, making September a unique time to experience Bangor’s charm. For a more comprehensive look at what to expect throughout the year, visit Bangor Climate.