September Weather in Portarlington, Ireland

Last updated: March 17, 2025

Experience the captivating weather of Portarlington, Ireland in September, where temperatures can soar to a maximum of 26°C (80°F), while the average rests comfortably at 14°C (57°F). Expect brisk mornings with minimum temperatures dipping to 0°C (33°F), making for a refreshing start to the day. With an average precipitation of 71 mm (2.8 in) over 12 days, this month tends to be moderately wet, contributing to the region's lush landscapes. The high humidity level of 86% adds to the atmospheric charm, enveloping the town in a soft, misty embrace. Whether you’re strolling through scenic views or enjoying local events, September in Portarlington offers a unique and inviting climate for all.

September Temperature in Portarlington

In September, Portarlington, Ireland, experiences a notable transition as summer gives way to autumn. The temperatures range from a minimum of 0°C (33°F) to a comfortable maximum of 26°C (80°F), with the average settling at 14°C (57°F). This month marks a continuation of the warmer weather enjoyed in the preceding months, particularly with the higher daytime temperatures reminiscent of August, yet it hints at the cooling that will come with October. As the days grow shorter and the air crisper, the vibrancy of early autumn begins to unfold, inviting residents and visitors alike to savor the scenic beauty before the chill of winter sets in.

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

The chart illustrates September temperature patterns in Portarlington, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec424345485358616056514644
Data source: Temperature data for Portarlington 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 Portarlington

In September, Portarlington experiences a moderate precipitation level of 71 mm (2.8 in), falling on about 12 days. This amount reflects a slight decrease from the previous month's 99 mm during the typically wetter August, suggesting a transition into drier conditions as autumn approaches. While September's rainfall is not as high as in the summer, it still maintains a consistent pattern seen earlier in the year, with precipitation figures hovering around the average seen during the late summer months. The relatively stable weather continues into October, where precipitation is expected to increase once again, emphasizing the region's characteristic maritime climate.

September Precipitation Trends in Portarlington

The chart displays monthly precipitation patterns in Portarlington, 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.
JanFebMarAprMayJunJulAugSepOctNovDec558682487270729971838393
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Portarlington

In September, Portarlington experiences a humidity level of 86%, continuing the trend of elevated moisture that characterizes much of the year. As summer transitions into autumn, humidity remains consistent with July and August, which also recorded 86%. This slight stability hints at the lingering warmth from the summer months, before a gradual increase to 87% in October. Notably, January through April display predominantly high humidity levels ranging from 85% to 86%, underlining the region's maritime climate. This consistent humidity not only contributes to the lush landscapes of Portarlington but also affects the overall feel of the weather, making it a defining feature of the local atmosphere throughout the year.

September Average Humidity in Portarlington

This chart illustrates the average monthly humidity levels in Portarlington, 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.
JanFebMarAprMayJunJulAugSepOctNovDec85%86%86%85%83%85%86%85%86%87%87%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Portarlington

As the seasons transition towards autumn, the September UV Index in Portarlington, Ireland typically reflects a moderate exposure level, registering at 5. This indicates a burn time of around 30 minutes for unprotected skin, a shift from the higher summer months where UV Index values peaked at 8. The trend suggests that while UV exposure decreases compared to the sizzling heights of June and July, it remains significant enough to necessitate caution, especially during midday hours. As warmer weather lingers, it is wise to stay vigilant and protect your skin from potential harm. For detailed insights on UV levels throughout the year, visit Portarlington UV Index.

Maximum UV Index Levels in Portarlington for September

The chart shows the monthly maximum UV Index (UVI) for Portarlington 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.
JanFebMarAprMayJunJulAugSepOctNovDec124578875321
Data source: Portarlington 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 Portarlington

As autumn approaches, September in Portarlington embraces a delightful transition marked by 274 hours of sunshine, providing a warm glow before winter sets in. This month, while slightly reduced from the sun-drenched days of summer—with July and June boasting peak totals of 365 and 363 hours respectively—still offers a considerable brightness compared to the chillier months ahead. The gradual decline begins from the sizzling heights of May, with 369 hours, reflecting a trend of diminishing daylight as the year progresses. Yet, September’s radiant skies invite locals and visitors alike to savor the lingering warmth and natural beauty of the Irish landscape, making it a cherished time to enjoy the outdoors before the frosty grip of winter takes hold.

Monthly Sunshine Duration in Portarlington: September Highlighted

The September sunshine duration represents the total number of hours Portarlington 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.
JanFebMarAprMayJunJulAugSepOctNovDec79h135h173h280h369h363h365h308h274h224h114h89h
Data source: Portarlington September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Portarlington During September

In September, the likelihood of sunny weather in Portarlington, Ireland stands at a modest 18%, a continuation of the subdued sunshine trend that characterizes the end of summer. As the year progresses, the chances of sunny days fluctuate, with April peaking at 40%. However, September’s figures reflect the gradual transition into fall, with likelihoods dipping from the slightly sunnier periods in May and June. This declining pattern is evident as the year moves towards its end, with October and November also showing lower probabilities of sunshine. Thus, while September still offers some potential for clearer skies, it's best to keep an umbrella handy as the weather tends to become more unpredictable.

Percentage of Sunny Days in September in Portarlington

The chart illustrates the percentage of sunny days in Portarlington 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 Portarlington experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec29%20%18%40%32%21%27%24%18%17%25%21%
Data source: Portarlington September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Portarlington in September

In September, daylight in Portarlington, Ireland, gently transitions towards the shorter days of autumn, offering about 12 hours of sunshine. This month marks a notable shift from the summer's peak, where July and June enjoyed a generous 16 hours of daylight, maintaining vibrant outdoor activities. As the lushness of summer fades, September still provides ample light compared to the early months of the year. For instance, after the mere 8 hours in January, the steady increase is palpable, peaking in June and July before beginning its gradual decline. This trend reflects the natural rhythm of the seasons, creating a perfect blend of late summer warmth and the impending charm of autumn.

Average Daylight Hours in Portarlington for September

The chart illustrates the variation in daylight duration in Portarlington throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 7m9h 49m11h 54m14h 2m15h 54m16h 53m16h 21m14h 40m12h 37m10h 30m8h 36m7h 34m
Data source: Portarlington daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Portarlington

In September, Portarlington experiences a gentle breeze with an average wind speed of 3.1 m/s (7 mph), marking a slight dip from the warmer summer months. This trend reflects a gradual transition towards autumn, as winds begin to calm following July's peak of 2.6 m/s (6 mph). Throughout the year, the wind speeds in this coastal town typically fluctuate, with January and October embracing more lively gusts of 3.8 m/s (8 mph) and 4.2 m/s (9 mph) respectively. Overall, September presents a serene atmosphere, perfectly balancing the quiet of fading summer and the crispness of approaching fall, inviting locals and visitors alike to enjoy the tranquil beauty of the Irish landscape.

Average September Wind Speed in Portarlington

The chart displays monthly wind speed patterns in Portarlington, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.85.24.13.13.63.42.63.23.1 m/s4.23.94.3
Data source: Portarlington September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Portarlington Compares to Other Months

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

In September, the weather is generally milder with temperatures ranging from a chilly 0°C (33°F) at night to a pleasant maximum of 26°C (80°F) during the day, alongside an average temperature of 14°C (57°F). The month sees about 71 mm (2.8 in) of precipitation over 12 days, coupled with high humidity levels at 86%.

Conversely, January brings a notable drop in temperatures, dipping to a minimum of -5°C (23°F) and averaging around 6°C (43°F). The maximum temperature only reaches 14°C (57°F), and the month has slightly less precipitation at 55 mm (2.1 in) spread across 10 days, while humidity remains relatively constant at 85%. For more detailed insights about January weather in Portarlington, you can check Portarlington weather in January.

September and February present notable contrasts in weather conditions. In September, temperatures range from a minimum of 0°C (33°F) to a maximum of 26°C (80°F), with an average of 14°C (57°F) and overall warmer days. Conversely, February experiences cooler temperatures, with a minimum of -3°C (27°F) and a maximum of 16°C (61°F), averaging only 6°C (44°F). Precipitation is also a factor, with September receiving 71 mm (2.8 in) of rain over 12 days, while February has a slightly higher precipitation total of 86 mm (3.4 in) spread over 15 days. Interestingly, both months feature a consistent humidity level of 86%. For more details on February weather, you can check out Portarlington weather in February.

In comparing the weather of September and March, it becomes evident that both months experience high humidity levels of 86%, contributing to a relatively damp atmosphere. September boasts milder temperatures with a minimum of 0°C (33°F) and an average of 14°C (57°F), reaching a maximum of 26°C (80°F). In contrast, March is noticeably cooler, with temperatures ranging from a minimum of -7°C (21°F) to an average of 7°C (45°F) and a maximum of 17°C (64°F). Additionally, March sees slightly more precipitation at 82 mm (3.2 in) over 16 days compared to September’s 71 mm (2.8 in) across 12 days. For more detailed information on March conditions, you can check Portarlington weather in March.

When comparing September and April weather, a notable difference emerges in both temperature and precipitation. September typically offers a milder climate, with average temperatures ranging from a minimum of 0°C (33°F) to a maximum of 26°C (80°F), while April sees temperatures that can drop to as low as -4°C (26°F) and only reach a maximum of 21°C (71°F). Precipitation is also more abundant in September, totaling 71 mm (2.8 in) over 12 days, compared to April's 48 mm (1.9 in) across 10 days. Interestingly, humidity levels remain fairly constant, hovering around 86% in September and 85% in April. For a more detailed overview of April weather in Portarlington, check out this link: Portarlington weather in April.

When comparing the weather in September and May, both months exhibit relatively similar characteristics in terms of temperature and precipitation. September sees a minimum temperature of 0°C (33°F) and an average of 14°C (57°F), while May has a slightly lower minimum of -1°C (30°F) and an average of 12°C (53°F). The maximum temperatures are comparable as well, with September reaching up to 26°C (80°F) and May peaking at 24°C (76°F). Both months receive about 71-72 mm (2.8 in) of precipitation over approximately 12 days, with humidity levels staying close at 86% in September and 83% in May. For more specific details on May weather, you can check Portarlington weather in May.

In comparing the weather between September and June, we notice a few similarities and differences. September experiences a wider range of temperatures, ranging from a chilly 0°C (33°F) at its minimum to a warm 26°C (80°F) at its peak, while June starts slightly warmer with a minimum of 4°C (40°F) and reaches a max of 28°C (83°F). Both months exhibit similar average temperatures at around 14°C (57°F for September and 58°F for June). Precipitation levels are comparable, with September receiving 71 mm (2.8 in) over 12 days, and June with slightly less at 70 mm (2.7 in) over 14 days. Humidity is also quite high in both months, at 86% in September and a touch lower at 85% in June. For more information on June weather specifically, you can visit Portarlington weather in June.

When comparing the weather in September to that of July, there are some notable differences. September experiences a wider temperature range, with minimum temperatures dropping to 0°C (33°F) compared to July's milder 6°C (43°F). The average temperature in September is 14°C (57°F), slightly cooler than July's 16°C (61°F), while the maximum temperature in September reaches 26°C (80°F), which is just a bit lower than July's top of 29°C (84°F). Both months receive comparable amounts of precipitation, with September totaling 71 mm (2.8 in) and July at 72 mm (2.8 in), occurring over the same number of days (12). However, humidity levels remain high and consistent at 86% for both months, contributing to a persistent feeling of dampness. For a closer look at July weather specifics, check out Portarlington weather in July.

In comparing the weather of September to that of August, September experiences a broader temperature range with a minimum of 0°C (33°F) and a maximum of 26°C (80°F), while August's temperatures are slightly higher, ranging from 6°C (43°F) to 24°C (75°F). The average temperature in September is 14°C (57°F), compared to 15°C (60°F) in August, indicating a slight cooling trend as summer transitions into autumn. Precipitation in September totals 71 mm (2.8 in) over 12 days, which is less than August's 99 mm (3.9 in) across 17 days, suggesting that September may be drier overall. Humidity levels remain relatively constant, with September at 86% and August slightly lower at 85%. For more detailed information on August weather specifically, you can check Portarlington weather in August.

In comparing the weather of September and October, September tends to be warmer, with daytime temperatures reaching a maximum of 26°C (80°F) and averaging around 14°C (57°F). The month experiences an average humidity of 86% and about 71 mm (2.8 in) of precipitation over 12 days. In contrast, October sees cooler temperatures, with a maximum of 20°C (68°F), an average of 11°C (51°F), and nights dipping to a minimum of -2°C (29°F). This month is slightly wetter, recording 83 mm (3.3 in) of rain over 15 days and a similar humidity level of 87%. For more detailed information, visit Portarlington weather in October.

In September, the weather features a minimum temperature of 0°C (33°F) and an average of 14°C (57°F), reaching a maximum of 26°C (80°F). With around 71 mm (2.8 in) of precipitation over approximately 12 days, humidity remains relatively high at 86%. In contrast, November brings cooler temperatures, with a minimum of -3°C (28°F) and an average of 8°C (46°F), peaking at 16°C (60°F). The month sees a slight increase in precipitation to 83 mm (3.3 in) over about 14 days, while humidity stays consistent at 86%. For more details, you can check out Portarlington weather in November.

In comparing the weather between September and December, notable differences in temperature and precipitation emerge. September typically enjoys milder conditions with temperatures ranging from a minimum of 0°C (33°F) to a maximum of 26°C (80°F), averaging around 14°C (57°F). In contrast, December experiences colder weather, with temperatures dropping to a minimum of -6°C (21°F) and peaking at 14°C (57°F), leading to an average of only 7°C (44°F). Furthermore, December tends to have more precipitation, totaling 93 mm (3.7 in) over 15 days, whereas September sees 71 mm (2.8 in) of rain across 12 days. Despite the higher precipitation in December, humidity remains relatively similar, with September at 86% and December at 84%. For more details, you can check out Portarlington weather in December.

Compare Portarlington's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Portarlington

As September arrives in Portarlington, the weather shifts significantly, offering a blend of mild warmth and the crispness of early autumn. With a maximum temperature reaching a comfortable 26°C, the days are still pleasantly warm, contrasting sharply with the cooler minimums that can dip to around 0°C. This month is marked by increased humidity levels, often peaking at 86%, and a bit more rainfall, with about 12 days experiencing precipitation amounting to 71 mm. While the vibrant summer warmth is gradually replaced by the chill of fall, September serves as a charming transition, making it an ideal time to explore the changing landscape. For a more detailed look at what to expect, visit Portarlington Climate.