September Weather in Porthleven, United Kingdom

Last updated: March 17, 2025

September in Porthleven, United Kingdom, presents a mild maritime climate with an average temperature of 16°C (60°F), reaching up to a pleasant 22°C (72°F) at its warmest. As the month unfolds, temperatures dip to a cool 10°C (50°F), inviting visitors to enjoy the refreshing coastal air. However, prepare for occasional rain, as 64 mm (2.5 in) of precipitation typically falls over 12 days, contributing to the area's lush greenery. With a humidity level averaging 84%, the air remains crisp and invigorating, perfect for exploring this charming seaside town and its stunning views.

September Temperature in Porthleven

In September, Porthleven, United Kingdom, experiences a transition into autumn, with temperatures reflecting the shifting season. The minimum temperature settles at around 10°C (50°F), while the average climbs to a comfortable 16°C (60°F), reaching a pleasant maximum of 22°C (72°F). This marks a gentle decline from the warmer summer months, yet the weather remains inviting, perfect for outdoor activities. As the month progresses, you can expect a gradual coolness, hinting at the cozy charm of autumn that awaits, while still enjoying the lingering warmth of late summer days.

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

The chart illustrates September temperature patterns in Porthleven, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec474848505459636260565250
Data source: Temperature data for Porthleven 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 Porthleven

In September, Porthleven experiences a notable transition in its weather patterns, as the average precipitation reaches 64 mm (2.5 in) over 12 days. This marks a slight uptick compared to the preceding month, August, which saw 57 mm (2.3 in), suggesting that autumn is beginning to assert itself. The rainfall in September strikes a balance, providing enough moisture to nurture the lush landscapes without overwhelming the town, setting the stage for the wetter months ahead. This month typically serves as a bridge, hinting at the dramatic increase in precipitation that follows with October delivering a substantial 120 mm (4.7 in). Thus, while September remains relatively mild, it subtly foreshadows the more pronounced rain characteristic of the season, wrapping the coastal town in a cozy yet dynamic climate.

September Precipitation Trends in Porthleven

The chart displays monthly precipitation patterns in Porthleven, 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.
JanFebMarAprMayJunJulAugSepOctNovDec739085466474705764120102123
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Porthleven

In September, Porthleven enjoys a slight dip in humidity, settling at 84%. This level reflects a subtle transition as summer wanes, following a consistent high of 85% from June through August. The humidity gradually begins to decrease during the fall months, with October mirroring September's conditions. Overall, while humidity remains relatively high throughout the year, September marks a gentle shift towards the fresher autumn air, making it a perfect time for coastal walks and enjoying the changing scenery.

September Average Humidity in Porthleven

This chart illustrates the average monthly humidity levels in Porthleven, 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.
JanFebMarAprMayJunJulAugSepOctNovDec81%84%82%83%85%85%85%85%84%84%82%81%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Porthleven

As September arrives in Porthleven, United Kingdom, the UV Index holds steady at a moderate 6, indicating a high exposure category and a burn time of 25 minutes. This follows the peak summer months where the UV Index soared to very high levels, particularly in June, July, and August, when sunbathers needed to be vigilant with only 15 minutes before risk of burning. As autumn approaches, it’s a reminder to remain cautious; while the intensity has decreased, the sun can still pose a threat, especially during those sunny days. For more detailed information on the UV Index throughout the year, check out Porthleven UV Index.

Maximum UV Index Levels in Porthleven for September

The chart shows the monthly maximum UV Index (UVI) for Porthleven 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.
JanFebMarAprMayJunJulAugSepOctNovDec234679886421
Data source: Porthleven 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 Porthleven

In September, Porthleven basks in a generous 330 hours of sunshine, marking the transition from the sun-drenched peak of summer. As the days start to shorten, the warmth of July and August, with their impressive totals of 427 and 387 hours respectively, lingers, creating a delightful atmosphere for locals and visitors alike. This month showcases a notable drop compared to the summer highs but remains substantially brighter than the onset of winter, with October further declining to just 261 hours. The gradual decrease in daylight hours serves as a gentle reminder of the approaching autumn, yet September's sunny disposition ensures a beautiful close to summer in this charming coastal town.

Monthly Sunshine Duration in Porthleven: September Highlighted

The September sunshine duration represents the total number of hours Porthleven 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.
JanFebMarAprMayJunJulAugSepOctNovDec94h156h235h354h407h403h427h387h330h261h156h118h
Data source: Porthleven September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Porthleven During September

In Porthleven, the likelihood of sunny weather in September holds steady at 33%, reflecting a trend of moderate sunshine as summer winds down. This percentage indicates a slight uptick compared to the preceding months, particularly August's 32%. As autumn approaches, the chances of enjoying sunny days don’t dramatically dip as they might in the fall, with October dropping to 30%, suggesting that September remains a lovely time to bask in whatever sun the coast offers. A glance at the year's data reveals that while spring and early summer months often enjoy higher sunny probabilities, September strikes a balance, maintaining a reasonable expectation of pleasant weather for those looking to savor the last rays of summer.

Percentage of Sunny Days in September in Porthleven

The chart illustrates the percentage of sunny days in Porthleven 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 Porthleven experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec27%24%34%52%38%31%40%33%33%30%24%20%
Data source: Porthleven September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Porthleven in September

As summer fades, September in Porthleven brings a gentle transition in daylight, offering around 12 hours of sunshine each day. Following the peak of June's 16 hours, the trend sees a gradual decline, with September marking a soft return to the shorter days of autumn. This month retains a comfortable brightness compared to the earlier winter months—8 hours in January and 9 in November—while still allowing for ample time to enjoy the coastal beauty. As daylight diminishes, it invites a reflective atmosphere, perfect for savoring the last warm days before the chill of fall settles in. Overall, September's daylight serves as a gentle reminder of the shifting seasons, bridging the vibrant energy of summer with the calm of autumn.

Average Daylight Hours in Porthleven for September

The chart illustrates the variation in daylight duration in Porthleven throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 35m10h 4m11h 55m13h 48m15h 26m16h 17m15h 50m14h 22m12h 33m10h 41m9h8h 7m
Data source: Porthleven daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Porthleven

As September arrives in Porthleven, United Kingdom, the winds begin to mellow, with average speeds dipping to 5.1 m/s (12 mph). This marks a subtle yet noticeable decline from the breezier summer months, where consistent winds around 5.3 m/s prevailed in both July and August. Following a trend of decreasing wind strength through the late spring and summer, September winds signal the transition toward autumn, yet they remain modest compared to the gustier conditions experienced earlier in the year. In contrast to the brisk winds of January and February, which peak at 7.0 m/s (16 mph) and 8.4 m/s (19 mph), September offers a gentle embrace, perfect for leisurely coastal strolls as nature shifts its palette.

Average September Wind Speed in Porthleven

The chart displays monthly wind speed patterns in Porthleven, 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.
JanFebMarAprMayJunJulAugSepOctNovDec7.08.46.65.66.94.65.35.35.1 m/s6.55.88.4
Data source: Porthleven September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Porthleven Compares to Other Months

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

When comparing the weather in September and January, notable differences emerge. September offers milder conditions with average temperatures ranging from a minimum of 10°C (50°F) to a maximum of 22°C (72°F), accompanied by higher humidity levels at 84%. In contrast, January presents a chillier climate, with temperatures peaking at 15°C (58°F) and dropping to a minimum of 2°C (36°F). While both months experience a similar number of rainy days—12—January receives slightly more precipitation at 73 mm (2.9 in) compared to September's 64 mm (2.5 in). For more specific insights, you can check the detailed outlook for Porthleven weather in January.

In September, the weather tends to be milder, with temperatures ranging from a low of 10°C (50°F) to an average of 16°C (60°F) and highs reaching up to 22°C (72°F). This month experiences about 64 mm (2.5 in) of precipitation over 12 days, accompanied by relatively high humidity at 84%. In contrast, February brings colder conditions, with temperatures dipping to a minimum of -1°C (31°F) and averaging around 9°C (48°F), peaking at 13°C (56°F). Precipitation is slightly higher at 90 mm (3.5 in) spread over 15 days, with a humidity level remaining close at 83%. For more specific details on February weather, check out Porthleven weather in February.

September typically enjoys milder weather compared to March, with average temperatures ranging from a minimum of 10°C (50°F) to a maximum of 22°C (72°F), while March experiences cooler temperatures, with a minimum of -2°C (28°F) and a maximum of 14°C (57°F). Precipitation levels are higher in March, totaling 85 mm (3.4 in) over 16 days, compared to September's 64 mm (2.5 in) across 12 days. Despite the slight difference in humidity, which is slightly higher in September at 84% versus 82% in March, the overall feel of September's weather tends to be more pleasant. For a detailed look at March weather specifically, you can check this link: Porthleven weather in March.

September weather is generally milder than that of April, with average temperatures ranging from a minimum of 10°C (50°F) to a maximum of 22°C (72°F), compared to April's min of 3°C (39°F) and max of 18°C (64°F). Additionally, September sees more precipitation, totaling 64 mm (2.5 in) over approximately 12 days, while April has less, with 45 mm (1.8 in) spread over 8 days. Both months have similar humidity levels, with September at 84% and April slightly lower at 83%. For more specific insights on April weather, check out Porthleven weather in April.

In comparing the weather of September and May, one can observe distinct differences in temperatures and overall climate conditions. September typically sees a minimum temperature of 10°C (50°F), averaging around 16°C (60°F), with highs reaching up to 22°C (72°F). In contrast, May has cooler temperatures, with a minimum of 6°C (42°F) and an average of 12°C (54°F), peaking at 20°C (68°F). Both months share a similar amount of precipitation, at 64 mm (2.5 in), though September experiences rainfall on 12 days compared to May's 11 days. Humidity levels are quite similar, with September at 84% and May at 85%. For more detailed information, you can check out Porthleven weather in May.

In comparing the weather between September and June, both months showcase relatively mild temperatures with a minimum of 10°C (50°F). However, September tends to be slightly warmer on average, at 16°C (60°F), compared to June's average of 15°C (59°F). June has a higher maximum temperature of 23°C (75°F), while September reaches a maximum of 22°C (72°F). Precipitation is more pronounced in June, with 74 mm (2.9 in) over 11 days, compared to September’s 64 mm (2.5 in) over 12 days. Humidity levels are fairly consistent in both months, hovering around 84% in September and 85% in June. To explore more about June weather, you can visit Porthleven weather in June.

When comparing the weather in September and July, we see notable differences in temperature and precipitation levels. September experiences slightly cooler temperatures, with a minimum of 10°C (50°F) and a maximum of 22°C (72°F), while July's temperatures range from a minimum of 12°C (53°F) to a maximum of 24°C (76°F). In terms of humidity, both months are quite similar, with September at 84% and July at 85%. Precipitation is also marginally higher in July with 70 mm (2.8 in) over 10 days, compared to September's 64 mm (2.5 in) over 12 days. For more details on July weather, you can check Porthleven weather in July.

In comparing the weather of September to that of August, we see a slight dip in temperatures, with September featuring a minimum of 10°C (50°F), while August had a minimum of 12°C (54°F). Both months share the same maximum temperature of 22°C (72°F), but September's average temperature of 16°C (60°F) is also just below August's average of 17°C (62°F). Precipitation levels are similar, with September receiving 64 mm (2.5 in) over 12 days, compared to 57 mm (2.3 in) over 11 days in August. Humidity is slightly lower in September at 84% compared to August's 85%. For more detailed information on August weather, you can visit Porthleven weather in August.

September offers milder temperatures with an average of 16°C (60°F) and a maximum of 22°C (72°F), while October sees a drop, with average temperatures around 13°C (56°F) and a maximum of 19°C (67°F). Precipitation increases significantly from 64 mm (2.5 in) in September to 120 mm (4.7 in) in October, and the number of rainy days rises slightly from 12 to 14. Despite the shift in temperature and a higher likelihood of rain, the humidity remains consistent at 84% for both months. For more specific details, check out Porthleven weather in October.

September tends to be milder with average temperatures ranging from 10°C (50°F) to a maximum of 22°C (72°F), while November sees a drop in temperatures, with averages between 5°C (40°F) and 16°C (61°F). Precipitation increases in November, averaging 102 mm (4.0 in) over 16 days, compared to September’s 64 mm (2.5 in) spread across 12 days. Despite the slight difference in humidity, both months remain relatively damp, with September at 84% and November at 82%. For more specific insights into November weather patterns, you can explore Porthleven weather in November.

In September, the weather features milder temperatures with an average of 16°C (60°F) and maximums reaching 22°C (72°F), making it ideal for outdoor activities. However, this month also sees considerable rainfall, with 64 mm (2.5 in) distributed over 12 days and an average humidity of 84%. In contrast, December presents a stark shift in climate, with average temperatures dropping to 10°C (50°F) and maximums peaking at just 14°C (58°F). It experiences significantly higher precipitation at 123 mm (4.8 in) over 19 days, accompanied by a slightly lower humidity level of 81%. For a more detailed outlook on December weather, you can visit Porthleven weather in December.

Compare Porthleven's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Porthleven

As September rolls in, Porthleven experiences a shift in weather that distinctly sets it apart from the preceding summer months. The temperatures become more moderate, averaging a comfortable 16°C (60°F), providing a delightful respite from the heat while still allowing for pleasant days. However, with this transition comes an increased chance of rain, as residents can expect about 12 days of precipitation, totaling 64 mm (2.5 in). The humidity peaks at 84%, creating a more refreshing, albeit damp atmosphere. This blend of moderate temperatures and rainfall marks September as a precursor to autumn's cozy embrace. For those curious about the overall climate patterns, check out Porthleven Climate for more insights.