September Weather in Nefyn, United Kingdom

Last updated: March 17, 2025

September in Nefyn, United Kingdom offers a blend of mild temperatures and notable rainfall, making it a month of transition. With maximums reaching 24°C (76°F) and averages at 15°C (59°F), the weather remains pleasant, though it can dip to a cool 9°C (49°F) at night. The landscape thrives under the weight of 162 mm (6.4 in) of rain, falling on approximately 18 days throughout the month, leading to an invigorating atmosphere enhanced by high humidity levels at 85%. This unique weather pattern invites visitors to experience Nefyn’s lush scenery while preparing for the refreshing yet unpredictable elements of early autumn.

September Temperature in Nefyn

September in Nefyn, United Kingdom, marks a delightful transition from the warmth of summer to the cooler embrace of autumn. With temperatures ranging from a mild 9°C (49°F) at night to a pleasant 24°C (76°F) during the day, this month offers a balanced and inviting climate for outdoor activities. The average temperature hovers around 15°C (59°F), making it one of the more temperate months of the year. As the days grow shorter, the refreshing sea breezes complement the warm afternoons, enticing locals and visitors alike to enjoy the stunning coastal scenery. Overall, September is a sweet spot for experiencing the best of Nefyn's charm before the chill of fall sets in.

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

The chart illustrates September temperature patterns in Nefyn, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec454545485257606058545047
Data source: Temperature data for Nefyn 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 Nefyn

September in Nefyn, United Kingdom, continues the trend of substantial rainfall experienced throughout the summer months, with 162 mm (6.4 in) of precipitation over 18 days. This marks a notable, yet slight decrease from August’s 166 mm and positions September within the upper range of the annual precipitation spectrum. As the skies shift from summer to the early hints of autumn, the increased rainfall is indicative of seasonal transitions, with October typically bringing even heavier downpours. Such patterns highlight the generally damp climate of this coastal locale, preparing residents and visitors alike for the wetter months ahead.

September Precipitation Trends in Nefyn

The chart displays monthly precipitation patterns in Nefyn, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1371721605983109108166162246215238
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Nefyn

As summer fades and autumn approaches, September in Nefyn, United Kingdom, experiences a noticeable rise in humidity, settling at 85%. This marks a slight increase from the drier months of July and August, which recorded 78% and 79% respectively. The transition into fall sees humidity levels climbing closer to spring averages, aligning with the trend of higher moisture in the air as the year progresses toward winter. Notably, this month acts as a precursor to the wetter months ahead, where October and November peak at 90% and 91%. Overall, September serves as a bridge between the warmth of summer and the chill of autumn, bringing with it a refreshing increase in humidity.

September Average Humidity in Nefyn

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

As summer fades into autumn, September's UV Index in Nefyn, United Kingdom, reflects a notable transition with a moderate rating of 5. This decrease from the high levels of July and August signals a shift in sun exposure, with an estimated burn time of 30 minutes for unprotected skin. While the risk remains moderate, September serves as a reminder to remain sun-aware, especially as outdoor activities continue. As the days grow shorter, it's essential to adapt sunscreen habits to align with the changing UV landscape. For more detailed insights and daily updates, visit the Nefyn UV Index.

Maximum UV Index Levels in Nefyn for September

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

As summer gracefully transitions into autumn, September in Nefyn, United Kingdom, offers a delightful retreat with an impressive 315 hours of sunshine. This month stands out, as it retains a significant portion of the summer's warmth, trailing only behind July's peak of 421 hours. The gradual decline in daylight from August's 383 hours is gentle, encouraging vibrant autumn colors to emerge while still allowing ample sunshine for outdoor activities. Comparing the month's sunshine to the colder, leaner months ahead, with October dipping to 238 hours and November dropping further to 126 hours, September serves as a comforting bridge, allowing residents and visitors alike to bask in the tail end of summer's glow before the darker days of winter set in.

Monthly Sunshine Duration in Nefyn: September Highlighted

The September sunshine duration represents the total number of hours Nefyn 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.
JanFebMarAprMayJunJulAugSepOctNovDec93h162h228h335h415h404h421h383h315h238h126h109h
Data source: Nefyn September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Nefyn During September

In Nefyn, United Kingdom, September offers a 24% chance of sunny weather, marking a noticeable decline from the more promising months of spring and summer. While April enjoys a peak at 48%, the likelihood of sunshine dips significantly as autumn approaches, following the patterns set in August and well before the onset of the drearier October. This trend highlights Nefyn’s transition into the cooler months, where the sunshine becomes more elusive, reminding residents and visitors alike that the vibrant days of summer are giving way to the mellow tones of fall.

Percentage of Sunny Days in September in Nefyn

The chart illustrates the percentage of sunny days in Nefyn 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 Nefyn experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec26%27%27%48%35%28%39%28%24%17%20%24%
Data source: Nefyn September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Nefyn in September

As September unfolds in Nefyn, the transition from the long, sun-soaked days of summer to the shorter autumnal light begins. With approximately 12 hours of daylight, September strikes a balance between the 16 hours enjoyed in June and July and the waning days that follow as autumn progresses. This notable decrease from the heights of summer serves as a gentle reminder of the changing seasons, as daylight gradually gives way to the deeper shadows of October, which offers just 10 hours. The shift is evident, yet September maintains a warm glow, inviting outdoor adventurers to savor the lingering light before winter darkness sets in.

Average Daylight Hours in Nefyn for September

The chart illustrates the variation in daylight duration in Nefyn throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 12m9h 52m11h 54m14h15h 50m16h 48m16h 16m14h 37m12h 36m10h 32m8h 39m7h 39m
Data source: Nefyn daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Nefyn

As September settles in Nefyn, United Kingdom, the transition to autumn is marked by a gentle average wind speed of 4.6 m/s (10 mph). This slight decrease in wind intensity from the summer months creates a tranquil atmosphere, contrasting with the breezier months of January and February, which boast averages of 6.9 m/s (15 mph) and 8.3 m/s (19 mph), respectively. Following a summer peak, where winds remain relatively mild, September showcases a lull that invites contemplation of the changing seasons. However, as the year progresses into October, Nefyn prepares to welcome invigorating gusts again, with average speeds jumping to 8.2 m/s (18 mph). This pattern reveals a rhythmic dance of winds throughout the year, with each month bringing its unique character, setting the stage for the vibrant autumn days ahead.

Average September Wind Speed in Nefyn

The chart displays monthly wind speed patterns in Nefyn, 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.
JanFebMarAprMayJunJulAugSepOctNovDec6.98.37.04.75.95.04.05.54.6 m/s8.27.27.6
Data source: Nefyn September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Nefyn Compares to Other Months

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

In September, the weather is milder with minimum temperatures of 9°C (49°F) and maximum temperatures reaching up to 24°C (76°F), making it ideal for outdoor activities. The month typically sees an average temperature of 15°C (59°F) and experiences significant precipitation of 162 mm (6.4 in) over about 18 days, along with a high humidity level of 85%.

In contrast, January brings much cooler conditions, with minimum temperatures dropping to 1°C (35°F) and maximum temperatures only reaching 13°C (56°F). The average temperature during this month is a chilly 7°C (45°F), and while precipitation is slightly lower at 137 mm (5.4 in) over approximately 16 days, humidity remains high at 89%. For a more detailed look at January weather, you can visit Nefyn weather in January.

September and February present contrasting weather patterns. In September, the temperatures are milder, with a minimum of 9°C (49°F) and an average of 15°C (59°F), peaking at a comfortable 24°C (76°F). The month experiences significant rainfall, with a total of 162 mm (6.4 in) spread across 18 days and a humidity level of 85%. In contrast, February is much cooler, with temperatures dipping to a minimum of -1°C (31°F) and averaging just 7°C (45°F), reaching a maximum of 13°C (56°F). Despite the chill, February sees slightly more precipitation at 172 mm (6.8 in) over 19 days, accompanied by higher humidity at 88%. For a closer look at February's weather in Nefyn, visit Nefyn weather in February.

In comparing the weather of September and March, it's evident that these two months offer quite distinct climates. September enjoys milder temperatures, with averages around 15°C (59°F) and a high that can reach 24°C (76°F), while March is significantly colder, with an average of only 7°C (45°F) and maximum temperatures peaking at 14°C (58°F). Both months experience substantial rainfall, with September slightly edging out March concerning total precipitation at 162 mm (6.4 in) compared to March’s 160 mm (6.3 in), although March sees precipitation on 19 days compared to September's 18. Humidity levels are fairly consistent, with September at 85% and March slightly higher at 86%. For a more detailed look at March weather, you can check Nefyn weather in March.

When comparing the weather in September to that of April, it's clear that September tends to be warmer, with average temperatures ranging from a minimum of 9°C (49°F) to a maximum of 24°C (76°F). In contrast, April experiences cooler temperatures, with a minimum of 3°C (38°F) and a maximum of 16°C (62°F). September also brings significantly more precipitation, averaging 162 mm (6.4 in) over 18 days, whereas April sees only 59 mm (2.3 in) over 10 days. Despite this, both months maintain high humidity levels, with September at 85% and April slightly lower at 84%. For a closer look at April's weather, visit Nefyn weather in April.

When comparing the weather in September and May, we see distinct differences in temperature and precipitation patterns. September boasts higher temperatures, ranging from a minimum of 9°C (49°F) to a maximum of 24°C (76°F), with an average of 15°C (59°F). In contrast, May is cooler, with temperatures starting at a minimum of 4°C (40°F) and peaking at 19°C (66°F), averaging around 11°C (52°F).

Additionally, September experiences greater rainfall, averaging 162 mm (6.4 in) over 18 days, while May sees significantly less precipitation at 83 mm (3.3 in) across 12 days. Humidity levels are also higher in September at 85%, compared to 79% in May, indicating a more humid atmosphere as summer transitions to autumn. For more details on May weather, check out Nefyn weather in May.

When comparing the weather in September and June, we see some intriguing similarities and differences. Both months experience a minimum temperature of 9°C (49°F) and reach a maximum of 24°C (76°F), but September tends to be slightly warmer on average at 15°C (59°F) compared to June's average of 14°C (57°F). However, September is significantly wetter, with 162 mm (6.4 in) of precipitation over 18 days, while June sees just 109 mm (4.3 in) over 15 days. Additionally, humidity levels are a bit higher in September at 85%, compared to June's 81%. For a closer look at the weather in Nefyn during June, check out Nefyn weather in June.

When comparing the weather in September and July, a few notable differences emerge. September features cooler temperatures overall, with a minimum of 9°C (49°F) and an average of 15°C (59°F), compared to July’s minimum of 12°C (53°F) and average of 16°C (60°F). Additionally, September experiences higher rainfall, accumulating 162 mm (6.4 in) over 18 days, while July has a milder 108 mm (4.3 in) across 13 rainy days. Humidity levels are also higher in September at 85%, compared to July's 78%. For more detailed weather information, you can check out Nefyn weather in July.

In September, the weather exhibits a broader temperature range compared to August, with minimums dropping to 9°C (49°F) and maximums reaching 24°C (76°F). This gives September an average temperature of 15°C (59°F), slightly lower than August's average of 16°C (61°F). Precipitation remains high in both months, with September receiving 162 mm (6.4 in) over 18 days, while August sees a similar amount of 166 mm (6.5 in) across 22 days. Notably, September has a higher humidity level at 85%, compared to August's 79%. For more specific insights regarding the climate, you can check Nefyn weather in August.

September and October present a notable transition in weather patterns. In September, temperatures range from a minimum of 9°C (49°F) to a maximum of 24°C (76°F), with an average of 15°C (59°F). The month experiences 162 mm (6.4 in) of precipitation over 18 days, contributing to a relative humidity of 85%.

In contrast, October brings cooler temperatures, with a minimum of 4°C (39°F) and a maximum of 19°C (66°F), averaging 12°C (55°F). This month sees increased precipitation, with 246 mm (9.7 in) falling over 23 days, leading to a higher humidity level of 90%. For a closer look at October weather specifics, check out Nefyn weather in October.

In comparing the weather patterns of September and November, it's evident that November brings cooler temperatures, with a minimum of 4°C (39°F) and an average of 10°C (50°F), compared to September's milder temperatures, which range from a minimum of 9°C (49°F) to a maximum of 24°C (76°F). September experiences significantly less precipitation at 162 mm (6.4 in) over 18 days, whereas November sees an increase in rainfall to 215 mm (8.5 in) across 22 days. The humidity also rises slightly in November to 91%, compared to September's 85%. For a closer look at November weather specifics, visit Nefyn weather in November.

In September, the weather is relatively mild with average temperatures ranging from 9°C (49°F) at night to a comfortable 24°C (76°F) during the day. However, the month experiences significant rainfall, totaling 162 mm (6.4 in) over approximately 18 days and maintaining a high humidity level of 85%. In contrast, December sees much cooler temperatures, with nighttime lows dropping to 2°C (36°F) and daytime highs reaching only 12°C (54°F). The precipitation in December is heavier, accumulating to 238 mm (9.4 in) across about 25 days, along with slightly higher humidity at 89%. For more details on December weather specifics, you can visit Nefyn weather in December.

Compare Nefyn's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Nefyn

As summer transitions to autumn, September in Nefyn presents a notable change in weather patterns. The air turns crisper with daily temperatures averaging around 15°C (59°F), significantly lower than the warmer months, while high humidity levels hover around 85%, lending a muggy feel to many days. Rainfall becomes more frequent, with precipitation occurring on over half the days of the month, totaling 162 mm (6.4 in). This shift into a wetter season sets the stage for more dramatic scenery, as the lush landscape contrasts beautifully with the often-gray skies. For a deeper understanding of how September fits into the yearly climate of this region, you can explore more at Nefyn Climate.