September Weather in Barmouth, United Kingdom

Last updated: March 17, 2025

September in Barmouth, United Kingdom brings a mix of mild temperatures and frequent showers. With a soaring maximum of 27°C (82°F), the month also features a cooler average of 13°C (56°F) and dips to a brisk minimum of 2°C (36°F). Rain is a constant companion, accumulating around 130 mm (5.1 in) over the course of 16 days, contributing to a notably high humidity level of 85%. This blend of warmth and moisture creates a unique environment, suggesting that visitors should prepare for both sunny days and wet weather as they enjoy the beauty of Barmouth.

September Temperature in Barmouth

In Barmouth, United Kingdom, September marks a transition into milder autumnal weather. With minimum temperatures settling around 2°C (36°F), the start of the month may feel a bit brisk, but average temperatures rise to a pleasant 13°C (56°F). As summer wanes, the maximum temperatures remain quite inviting at 27°C (82°F), reminiscent of the warmer months, allowing for lingering days outdoors. This blend of early autumn coolness and late summer warmth makes September an ideal time to explore Barmouth's stunning scenery before the chill of winter sets in. The gradual shift in temperatures signals nature's changing palette, inviting both locals and visitors to savor the beauty of this coastal gem.

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

The chart illustrates September temperature patterns in Barmouth, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec414244485258615956514643
Data source: Temperature data for Barmouth generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Barmouth

September in Barmouth, United Kingdom, sees a notable decline in precipitation compared to the summer months, with 130 mm (5.1 in) of rainfall spread over 16 days. This represents a shift from the wet August, which recorded 144 mm (5.7 in). The transition into autumn brings a more temperate climate, yet the increase in precipitation returns in October, sharply rising to 161 mm (6.3 in), indicating that while September offers a brief respite, the wetter months are just around the corner. Overall, the month's rainfall is significant but less intense than the high points of summer, hinting at the changing seasons and the dynamic weather patterns that characterize this coastal region.

September Precipitation Trends in Barmouth

The chart displays monthly precipitation patterns in Barmouth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec10514513858859691144130161138170
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Barmouth

In Barmouth, United Kingdom, September's humidity levels sit at a comfortable 85%, marking a brief dip from the peak summer months. This slight decrease contrasts with the higher average of 91% during the late autumn months of November and October, showcasing the seasonal shift towards wetter weather. As summer ebbs, humidity begins to rise again towards the year's end, making the transition from the relatively drier summer months of July and August, which hover around 78% to 79%. The consistent humidity trends throughout the year suggest that Barmouth experiences a distinctly maritime climate, characterized by high moisture levels that keep it lush and vibrant, especially as it heads into the brisker fall.

September Average Humidity in Barmouth

This chart illustrates the average monthly humidity levels in Barmouth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec89%88%86%85%79%81%78%79%85%90%91%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Barmouth

As September arrives in Barmouth, the UV Index begins to exhibit a noticeable decline from the peak summer values. With a UV Index of 5, exposure is categorized as moderate, allowing for a burn time of approximately 30 minutes—plenty of time for outdoor enjoyment while still requiring some sun protection. This shift follows the high levels of 7 and very high 8 experienced in August and July, respectively. As autumn sets in, it's essential to stay aware of these trends in UV exposure, especially as the days grow shorter. For more detailed information about UV levels throughout the year, check out the Barmouth UV Index.

Maximum UV Index Levels in Barmouth for September

The chart shows the monthly maximum UV Index (UVI) for Barmouth 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.
JanFebMarAprMayJunJulAugSepOctNovDec124578875421
Data source: Barmouth 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 Barmouth

As summer gracefully fades into autumn, September in Barmouth offers a delightful blend of warmth and sunshine, showcasing 313 hours of sunlight. This marks a gentle transition from the peak summer months, where July boasts an impressive 420 hours. After the sun-drenched days of May and June, it's clear that Barmouth continues to bask in generous light even as the seasons change. While September’s hours dwindle compared to the radiant summer, they still outshine the dimmer, winter months ahead, like the glimmering 125 hours in November. Visitors can relish this vibrant month, surrounded by picturesque views and the lingering warmth of late summer sunsets.

Monthly Sunshine Duration in Barmouth: September Highlighted

The September sunshine duration represents the total number of hours Barmouth 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.
JanFebMarAprMayJunJulAugSepOctNovDec94h158h225h330h411h402h420h385h313h239h125h106h
Data source: Barmouth September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Barmouth During September

In Barmouth, United Kingdom, September offers a modest 21% chance of sunny weather, reflecting a transition into autumn as summer's warmth begins to wane. This percentage is slightly lower than the spring peak in April, where sunny days surge to 47%. As the year progresses, the likelihood of sunny days generally declines, with late spring and early summer months seeing better prospects, particularly in April and July. While September’s sunny potential isn’t as high as earlier months, it still offers a reasonable chance for those looking to enjoy some rays before the colder months set in.

Percentage of Sunny Days in September in Barmouth

The chart illustrates the percentage of sunny days in Barmouth 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 Barmouth experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec17%20%25%47%28%24%36%23%21%15%22%16%
Data source: Barmouth September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Barmouth in September

As summer gracefully yields to autumn, September in Barmouth offers a gentle transition in daylight hours, with the sun casting its warm glow for about 12 hours each day. This marks a notable decline from the peak of 16 hours in June and July, reflecting nature's shift toward shorter days. However, compared to the preceding months, September still boasts a fine balance of light, bridging the gap between the vibrant summer months and the coziness of the upcoming fall. As the days grow shorter and the evenings become crisper, September invites locals and visitors alike to savor the lingering daylight before winter takes its hold.

Average Daylight Hours in Barmouth for September

The chart illustrates the variation in daylight duration in Barmouth throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 13m9h 52m11h 54m13h 59m15h 48m16h 46m16h 15m14h 36m12h 36m10h 32m8h 41m7h 41m
Data source: Barmouth daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Barmouth

As summer fades into autumn, September in Barmouth presents a gentle breeze, with an average wind speed of 2.9 m/s (6 mph). This marks a slight decline from the peak summer winds, which often reached their lowest in July at 2.5 m/s (5 mph). Following September, winds pick up again in October, suggesting a transition to more invigorating conditions as the year progresses. Overall, the trend reveals that the region enjoys its calmest winds during the summer months, with a noticeable escalation in the briskness of the breeze as colder weather approaches. The subtle shift in September captures the essence of seasonal change, inviting both locals and visitors to enjoy the serene beauty of Barmouth before winter sets in.

Average September Wind Speed in Barmouth

The chart displays monthly wind speed patterns in Barmouth, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.05.14.43.03.63.02.53.42.9 m/s4.63.94.4
Data source: Barmouth September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Barmouth Compares to Other Months

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

In September, the weather in Barmouth is characterized by mild temperatures, ranging from a minimum of 2°C (36°F) to a maximum of 27°C (82°F), with an average of around 13°C (56°F). The month sees a fair amount of rainfall, totaling 130 mm (5.1 in) over 16 days, and an average humidity of 85%. In contrast, January brings colder conditions, with temperatures dipping to a minimum of -3°C (26°F) and peaking at 13°C (56°F), resulting in an average of 5°C (42°F). While January experiences slightly less precipitation at 105 mm (4.2 in) over 14 days, humidity remains high at 89%. For more specific insights on January weather, visit Barmouth weather in January.

In comparing the weather of September and February, notable differences emerge in both temperature and precipitation patterns. September typically presents milder conditions, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 27°C (82°F), averaging around 13°C (56°F). In contrast, February experiences cooler temperatures, where it can drop to -5°C (24°F) at night and peak at 18°C (65°F), averaging 6°C (43°F). Additionally, February sees slightly higher precipitation levels at 145 mm (5.7 in) over 17 days compared to September's 130 mm (5.1 in) across 16 days, illustrating a wetter disposition during the winter month. For a more detailed look at February weather, you can visit Barmouth weather in February. Furthermore, February’s increased humidity at 88% compared to September’s 85% adds to its chilly ambiance, creating a stark contrast between the late summer and mid-winter conditions.

In comparing the weather of September and March, notable differences emerge. September generally exhibits milder temperatures, with averages around 13°C (56°F) and a maximum of 27°C (82°F), while March sees cooler conditions, averaging 7°C (44°F) and peaking at 18°C (65°F). Precipitation is quite similar, with September receiving 130 mm (5.1 in) over 16 days and March slightly higher at 138 mm (5.5 in) across 18 days. Humidity levels are also comparable, with September at 85% and March just slightly higher at 86%. For more detailed insights into March weather specifically, check out Barmouth weather in March.

September and April present distinct weather profiles. September generally features a wider temperature range, with minimums around 2°C (36°F) and maximums reaching up to 27°C (82°F), while April tends to be cooler, with temperatures ranging from a minimum of -3°C (28°F) to a maximum of 22°C (72°F). Precipitation is higher in September, averaging 130 mm (5.1 in) over 16 days, compared to April’s 58 mm (2.3 in) over 12 days. Despite this, both months share similar humidity levels, with September at 85% and April slightly lower at 84%. For a closer look at April weather specifics, you can visit Barmouth weather in April.

In September, the weather tends to be warmer on average compared to May, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 27°C (82°F), while in May, temperatures can drop to as low as 0°C (32°F) but also reach a similar maximum of 27°C (80°F). September experiences higher precipitation, with 130 mm (5.1 in) spread over 16 days, compared to May's 85 mm (3.3 in) over 13 days. Additionally, September's humidity is slightly higher at 85%, while May averages 79%, contributing to a somewhat more comfortable feel as spring transitions into fall. For more specific details about May weather in Barmouth, you can visit Barmouth weather in May.

In comparing the weather between September and June, we observe that September has a broader temperature range, with minimums dropping to 2°C (36°F) and maximums reaching 27°C (82°F), while June's temperatures start higher with a minimum of 5°C (42°F) and a maximum of 28°C (83°F). Precipitation in September is also more substantial, averaging 130 mm (5.1 in) over 16 days compared to June's 96 mm (3.8 in) on the same number of days. Despite this, the humidity is slightly higher in September at 85%, compared to June's 81%. For more detailed insights into June weather, you can visit Barmouth weather in June.

In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 27°C (82°F), with an average of 13°C (56°F), indicating a notable drop compared to July, which features a minimum of 6°C (44°F) and a maximum of 29°C (84°F) with an average of 16°C (61°F). Additionally, September sees higher precipitation, totaling 130 mm (5.1 in) over 16 days, compared to July's 91 mm (3.6 in) over 14 days, suggesting a wetter month to close out the summer. Humidity levels also rise in September, averaging 85%, versus 78% in July, contributing to a more damp and cooler feel as autumn approaches. For more details on July weather, you can check Barmouth weather in July.

In comparison to August, September experiences a notable drop in minimum temperatures, with lows dipping to 2°C (36°F) compared to August's 7°C (45°F). The average temperature in September is also slightly lower at 13°C (56°F), while both months share the same maximum temperature of 27°C (82°F). While both months see substantial rainfall, September records 130 mm (5.1 in) of precipitation over 16 days, which is less than the 144 mm (5.7 in) experienced in August across 20 days. Additionally, September's humidity is higher at 85%, compared to August's 79%. For more details, you can check Barmouth weather in August.

In September, the weather features a mild temperature range with a minimum of 2°C (36°F), an average of 13°C (56°F), and a maximum of 27°C (82°F). While this month sees less precipitation, registering 130 mm (5.1 in) over 16 days, it is marked by relatively high humidity at 85%. In contrast, October experiences cooler temperatures, with a minimum of -2°C (28°F), an average of 11°C (52°F), and a maximum of 21°C (70°F). This month is also wetter, as it receives 161 mm (6.3 in) of rainfall over 19 days, accompanied by even higher humidity at 90%. For more detailed information, check out Barmouth weather in October.

September and November present quite different weather patterns. In September, temperatures range from a minimum of 2°C (36°F) to a comfortable maximum of 27°C (82°F), yielding an average of 13°C (56°F). The month experiences approximately 130 mm (5.1 in) of rainfall over 16 days, with humidity levels around 85%. In contrast, November sees cooler temperatures, with a minimum of -1°C (30°F) and an average of just 8°C (47°F), peaking at 15°C (59°F). This month is slightly wetter, with 138 mm (5.4 in) of precipitation over 19 days, and humidity rises to 91%. For more detailed insights, you can explore Barmouth weather in November.

September and December present striking contrasts in weather. September features a milder temperature range, with minimums around 2°C (36°F) and maximums reaching 27°C (82°F), averaging at 13°C (56°F). It is also marked by relatively high humidity at 85% and has 130 mm (5.1 in) of rainfall spread over about 16 days. In contrast, December sees temperatures drop significantly, with minimums plummeting to -3°C (26°F) and maxima capping at 13°C (55°F), resulting in a colder average of 6°C (44°F). Additionally, December experiences more precipitation, with 170 mm (6.7 in) over 20 days and slightly higher humidity at 89%. For more details on December weather, visit Barmouth weather in December.

Compare Barmouth's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Barmouth

As September rolls into Barmouth, the weather shifts distinctly from the summer months, showcasing cooler temperatures that settle into a comfortable average while still allowing for occasional warm days under clear skies. This transitional period, with higher humidity levels and a noticeable increase in precipitation, signifies the onset of autumn, contributing to a vibrant change in the landscape. Rainfall can be expected on nearly half of the month’s days, making it crucial for visitors to pack accordingly. Overall, the September weather invites a unique experience, blending the lingering warmth of summer with the fresh, crisp feel of early fall. For a more in-depth look at Barmouth's weather throughout the year, check out Barmouth Climate.