September Weather in Harlech, United Kingdom

Last updated: March 17, 2025

Experience the captivating September weather in Harlech, United Kingdom, where temperatures range from a delightful maximum of 27°C (82°F) to a cooler minimum of 2°C (36°F), presenting an average of 13°C (56°F). This month, the landscape is nourished by 130 mm (5.1 in) of rainfall spread across 16 days, contributing to the lush greenery characteristic of this region. With humidity levels soaring at 85%, visitors can expect a mix of refreshing breezes and occasional showers, making September an enchanting time to explore the historic charm of Harlech.

September Temperature in Harlech

September in Harlech marks a delightful transition as summer gently gives way to autumn. With minimum temperatures hovering around 2°C (36°F) and averaging a comfortable 13°C (56°F), the month still boasts pleasant highs reaching up to 27°C (82°F). This gradual cooling trend is notable, as it follows the warmer months of July and August, where temperatures peaked at 29°C (84°F) and 27°C (80°F), respectively. As the days begin to shorten, the crispness in the air becomes more pronounced, signaling the approach of cooler weather, yet the remnants of summer linger, offering the perfect backdrop for outdoor activities and explorations in this stunning corner of Wales.

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

The chart illustrates September temperature patterns in Harlech, 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 Harlech 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 Harlech

September in Harlech, United Kingdom, showcases a shift towards the wetter months, with 130 mm (5.1 in) of precipitation recorded over 16 days. This is a notable increase from the preceding drier summer months, where rainfall was moderate but less frequent. With September's rain, the landscape transitions into a vibrant tapestry of autumn hues. Although the amount of rainfall is less than in October—typically the wettest month at 161 mm (6.3 in)—September's totals still indicate a significant uptick from the drier spring months, culminating in increased moisture that supports local flora and prepares the region for the chillier, wetter days ahead. As Harlech steps deeper into fall, the consistent precipitation sets the stage for the lush, green surroundings that characterize the upcoming months.

September Precipitation Trends in Harlech

The chart displays monthly precipitation patterns in Harlech, 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.
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September Humidity in Harlech

As summer fades into autumn, September in Harlech witnesses a shift in humidity levels, with an average of 85%. This marks a slight increase from the drier months of July and August, which had humidity levels of 78% and 79% respectively. As the leaves begin to turn, the air becomes noticeably more humid, paving the way for the more moisture-laden months ahead. October and November follow suit, bringing even higher humidity levels of 90% and 91%. Overall, the trend highlights a gradual rise in humidity as the year progresses towards winter, with January and December remaining among the most humid months at 89%.

September Average Humidity in Harlech

This chart illustrates the average monthly humidity levels in Harlech, 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 Harlech

As September rolls into Harlech, the UV Index reflects a notable transition, settling at a moderate 5. This marks a slight decline from the peak summer months, where levels soared to 8 in both June and July, prompting caution for sun exposure. With a recommended burn time of 30 minutes, it’s a perfect reminder to stay protected during outdoor activities while enjoying the milder autumn sun. This gradual shift continues into October, with the index dipping to 4, but still retains a similar burn time. Keep an eye on the weather and sun levels this month to enjoy your time outdoors safely. For more detailed information, visit Harlech UV Index.

Maximum UV Index Levels in Harlech for September

The chart shows the monthly maximum UV Index (UVI) for Harlech 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: Harlech 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 Harlech

As September unfolds in Harlech, **sunshine bathes the landscape with a generous 313 hours of sunlight, providing a delightful send-off to summer. This month, while still abundant in bright days, marks a gradual decline from the peak of 420 hours in July, signaling the shift toward autumn. The warm glow of September sun not only nurtures the lingering blooms but also invites locals and visitors alike to revel in the last moments of outdoor leisure before the days shorten further. With sunlight steadily tapering after the lively summer months, September becomes a vibrant transition, blending warm hues with the crispness of approaching fall.

Monthly Sunshine Duration in Harlech: September Highlighted

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

Chance of Sun in Harlech During September

As summer wanes, September in Harlech, United Kingdom, displays a modest 21% chance of sunny weather, highlighting a slight decrease from the previous month’s 23%. This trend reflects a common pattern as the days become shorter and temperatures begin to cool. Interestingly, April boasts the highest likelihood of sunshine at 47%, setting it apart from the later months where chances tend to fluctuate but remain lower, particularly leading into the autumn months. Overall, while September offers some sunny moments, it's clear that the brilliance of summer gradually fades, paving the way for the cloudier days ahead.

Percentage of Sunny Days in September in Harlech

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

Daylight Hours in Harlech in September

As September unfolds in Harlech, the days begin to shorten, bringing 12 hours of daylight—a delightful balance after the sun-drenched summer months, where daylight peaked at an impressive 16 hours in June and July. This gradual decline in daylight duration, following a steady ascent from just 8 hours in January, signals the shift toward autumn as the long, sunlit evenings of May and June give way to the crisp, cool air of fall. Although September offers fewer daylight hours than its summer predecessors, it still retains a warm glow, making it an ideal time for outdoor adventures and enjoying the stunning coastal scenery before the days continue to wane into the darker months ahead.

Average Daylight Hours in Harlech for September

The chart illustrates the variation in daylight duration in Harlech 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: Harlech daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Harlech

As September sweeps into Harlech, the winds begin to whisper of change, with an average speed of 2.9 m/s (6 mph). This marks a subtle dip compared to the summer months, where July's gentle breezes at 2.5 m/s (5 mph) brought a tranquil calm, and August’s increase to 3.4 m/s (8 mph) hinted at the transition to autumn. Interestingly, September's winds remain softer than the blustery gusts of October, which typically pick up to 4.6 m/s (10 mph) as the season deepens. Overall, the month stands as a gentle interlude, bridging the calm warmth of summer with the invigorating breezes that herald the fall, showcasing nature's rhythm in this coastal haven.

Average September Wind Speed in Harlech

The chart displays monthly wind speed patterns in Harlech, 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: Harlech September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Harlech Compares to Other Months

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

September and January exhibit significantly different weather patterns. 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) and relatively high humidity at 85%. The month also sees considerable precipitation, with about 130 mm (5.1 in) over 16 days. In contrast, January experiences much colder conditions, with temperatures ranging from -3°C (26°F) to a maximum of 13°C (56°F) and an average of 5°C (42°F). Precipitation decreases slightly to 105 mm (4.2 in) over 14 days, and humidity rises to 89%. For more details on January weather, you can visit Harlech weather in January.

When comparing the weather in September and February, notable differences emerge. September offers a wider temperature range, with minimums of 2°C (36°F) and maximums reaching 27°C (82°F), creating a pleasant average of 13°C (56°F). In contrast, February is generally colder, featuring minimums of -5°C (24°F) and maximums of 18°C (65°F), resulting in a cooler average of 6°C (43°F). Rainfall is significant in both months, with September receiving 130 mm (5.1 in) over 16 days and February slightly wetter with 145 mm (5.7 in) over 17 days. While humidity levels are relatively high in both months, February's 88% slightly surpasses September's 85%, creating a chilly atmosphere. For further details, you can refer to Harlech weather in February.

Comparing the weather in September and March reveals distinct seasonal characteristics. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 27°C (82°F), averaging 13°C (56°F), while March sees cooler conditions with a low of -6°C (21°F) and a high of up to 18°C (65°F), averaging just 7°C (44°F). Additionally, both months experience significant precipitation, with September receiving about 130 mm (5.1 in) over 16 days, compared to March's slightly higher 138 mm (5.5 in) over 18 days. Humidity levels are similar, hovering around 85% in September and slightly higher at 86% in March. For more detailed information, check out Harlech weather in March.

When comparing the weather in September and April, notable differences emerge. September boasts a milder average temperature of 13°C (56°F) with highs reaching up to 27°C (82°F), whereas April's temperatures are cooler, averaging 9°C (48°F) with a maximum of 22°C (72°F). In terms of precipitation, September experiences significantly more rain, totaling 130 mm (5.1 in) over 16 days, while April has a much lighter rainfall of 58 mm (2.3 in) spread across 12 days. Humidity levels are quite similar in both months, with September at 85% and April slightly lower at 84%. For a closer look at April weather specifics, you can refer to Harlech weather in April.

When comparing the weather in September and May, several notable differences emerge. September boasts a wider temperature range, with minimums around 2°C (36°F) and maximums reaching 27°C (82°F), while May has a slightly cooler minimum of 0°C (32°F) but similar maximums of 27°C (80°F). Precipitation levels are also higher in September, with 130 mm (5.1 in) accumulating over 16 days, compared to May's 85 mm (3.3 in) across 13 days. Additionally, September tends to be more humid at 85%, whereas May's humidity is slightly lower at 79%. For more detailed insights into May's weather specifically, you can check Harlech weather in May.

When comparing the weather in September and June, we observe some notable differences. September experiences a broader temperature range with minimums dropping to 2°C (36°F) and maximums reaching 27°C (82°F), while June's temperatures are slightly warmer, ranging from a minimum of 5°C (42°F) to a maximum of 28°C (83°F). In terms of precipitation, September sees a higher total of 130 mm (5.1 in) over 16 days compared to June's 96 mm (3.8 in) over the same number of days, indicating that September tends to be wetter. Additionally, September has a slightly higher humidity level at 85%, compared to June's 81%. For more detailed insights, you can check Harlech weather in June.

When comparing the weather of September and July, we observe notable differences in temperature and precipitation. September boasts a broader temperature range, with minimums dropping to 2°C (36°F) and maximums reaching up to 27°C (82°F), while July maintains slightly warmer conditions, with minimums of 6°C (44°F) and maximums of 29°C (84°F). Additionally, September tends to be wetter, receiving 130 mm (5.1 in) of precipitation over 16 days, compared to July's 91 mm (3.6 in) over 14 days. Humidity levels are also higher in September at 85%, compared to July's 78%. For more detailed information on July conditions, you can check Harlech weather in July.

In comparing the weather between August and September, we can see notable differences in temperature and precipitation. September tends to be cooler, with a minimum temperature of 2°C (36°F), compared to August's warmer minimum of 7°C (45°F). The average temperatures are also slightly lower in September at 13°C (56°F) compared to 15°C (60°F) in August. Interestingly, both months share a maximum temperature of 27°C (82°F) in September and 27°C (80°F) in August, indicating there can still be quite warm days in both months.

However, September experiences more rain, with a total precipitation of 130 mm (5.1 in) over 16 days, while August has higher precipitation of 144 mm (5.7 in) across 20 days. The humidity is also higher in September at 85%, compared to August's 79%. For a detailed look at the weather conditions, you can check Harlech weather in August.

September and October present a notable transition in weather patterns. In September, temperatures range from a mild minimum of 2°C (36°F) to a maximum of 27°C (82°F), with an average of 13°C (56°F). This month experiences 130 mm (5.1 in) of precipitation over 16 days, accompanied by a humidity level of 85%. In contrast, October sees cooler temperatures, with lows dipping to -2°C (28°F) and a maximum of 21°C (70°F), averaging 11°C (52°F). Precipitation increases to 161 mm (6.3 in) over 19 days, and humidity rises slightly to 90%. For more specifics on October weather, you can check out Harlech weather in October.

September and November exhibit notable differences in weather patterns. In September, temperatures range from a mild minimum of 2°C (36°F) to a warm maximum of 27°C (82°F), with an average of 13°C (56°F). The month experiences significant precipitation, totaling 130 mm (5.1 in) over approximately 16 rainy days, and the humidity sits at a comfortable 85%.

In contrast, November sees cooler temperatures, with a minimum of -1°C (30°F) and a maximum of 15°C (59°F), resulting in an average temperature of 8°C (47°F). This month is slightly wetter, receiving 138 mm (5.4 in) of rainfall over 19 days, and experiences increased humidity levels at 91%. To learn more about specific weather patterns, you can check Harlech weather in November.

In September, the weather is generally milder with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 27°C (82°F) and an average of 13°C (56°F). This month sees about 130 mm (5.1 in) of precipitation over 16 days, with humidity levels around 85%. In contrast, December brings much colder conditions, with temperatures dipping as low as -3°C (26°F) and peaking at 13°C (55°F), averaging only 6°C (44°F). Additionally, December experiences increased precipitation at 170 mm (6.7 in) across 20 days, accompanied by slightly higher humidity at 89%. For more specific insights into December weather, check this link: Harlech weather in December.

Compare Harlech's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Harlech

As September unfolds in Harlech, the weather paints a vibrant transition from summer's warmth to autumn's crispiness. Visitors can experience a pleasant mix of temperatures, with daytime highs inviting the lingering sun, while cooler evenings remind us that fall is on the horizon. This month is characterized by a noticeable increase in precipitation, with rainy days more frequent than in the preceding summer months, contributing to the lush landscapes typical of the region. Alongside the elevated humidity, September offers a unique blend of both mild and brisk days, making it a captivating time for those exploring the beauty of Harlech. For more insights into what to expect throughout the year, check out Harlech Climate.