September Weather in Portrush, United Kingdom

Last updated: March 17, 2025

Experience the charm of Portrush, United Kingdom in September, where the coastal beauty meets a mild climate. Average temperatures linger around 14°C (57°F), with daily highs reaching a pleasant 17°C (64°F) and nighttime lows dipping to 9°C (49°F). September is characterized by its high humidity levels at 88%, making the air feel fresh and invigorating. Be prepared for a fair amount of rain, as the month sees about 117 mm (4.6 in) of precipitation spread across 20 days, offering plenty of opportunities for cozy indoor activities amidst the unpredictable weather. Whether you’re strolling along the beach or exploring local sights, September in Portrush promises a unique blend of scenic beauty and atmospheric charm.

September Temperature in Portrush

September in Portrush, United Kingdom marks a gentle transition from summer to autumn, with temperatures gradually cooling. The month opens with a minimum temperature of 9°C (49°F), hinting at the crispness to come, while the average hovers around 14°C (57°F) and peaks at 17°C (64°F). This reflects a slight warm-down from the summer highs, yet still offers pleasant conditions ideal for enjoying the coastal scenery. As daylight begins to wane and the vibrant hues of fall emerge, September provides a refreshing blend of warmth and coolness, making it a unique time to experience the beauty of Portrush.

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

The chart illustrates September temperature patterns in Portrush, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec454444465054575856534946
Data source: Temperature data for Portrush 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 Portrush

In September, Portrush experiences a considerable 117 mm (4.6 in) of precipitation, making it one of the wetter months of the year. With rainy days totaling 20, this increase follows the trend set by August, which had the highest rainfall at 146 mm (5.7 in). Notably, the number of rainy days during September is tied with August, suggesting a sustained pattern of unsettled weather as summer transitions into autumn. The precipitation amount decreases significantly in October and November, where the rainfall intensifies again in December. Overall, September serves as a bridge between the peak summer rains and the deeper, more persistent autumn showers that are characteristic of Portrush.

September Precipitation Trends in Portrush

The chart displays monthly precipitation patterns in Portrush, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1091321125573105110146117161156166
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Portrush

In September, Portrush experiences a slight uptick in humidity, with levels reaching 88%, marking it as one of the more humid months of the year. This increase follows a summer characterized by relatively stable humidity levels of 86% in both July and August. As autumn approaches, the transition manifests in a gradual rise in moisture in the air, paving the way for the even higher levels of 89% and 90% that are typical in October and November, respectively. This trend suggests that while summer brings some respite from humidity, the lingering warmth of early fall keeps moisture in the atmosphere prevalent, highlighting Portrush's characteristic dampness as it heads into the cooler months.

September Average Humidity in Portrush

This chart illustrates the average monthly humidity levels in Portrush, 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.
JanFebMarAprMayJunJulAugSepOctNovDec87%86%86%85%82%84%86%86%88%89%90%87%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Portrush

As September arrives in Portrush, the UV Index reflects a gradual transition toward cooler autumn days, with a moderate rating of 5. This marks a slight decrease from the high levels experienced in the summer months of July and August, where values peaked at 8. As the sun's intensity diminishes, the recommended burn time extends to 30 minutes, providing a comfortable window for enjoying outdoor activities while still being mindful of sun protection. This trend highlights the importance of adapting to seasonal changes in UV exposure. To stay informed on UV levels throughout the year, be sure to check Portrush UV Index.

Maximum UV Index Levels in Portrush for September

The chart shows the monthly maximum UV Index (UVI) for Portrush 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.
JanFebMarAprMayJunJulAugSepOctNovDec123568865321
Data source: Portrush 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 Portrush

September in Portrush, United Kingdom, marks a transition in the weather, as summer's warmth begins to wane. With 283 hours of sunshine, it still offers a generous amount of light, outshining the gloom of the coming months. While the brightness of May peaks at 405 hours, and July competes closely with 404 hours, September holds its own amidst the changing seasons, providing a softer sun that signals the onset of autumn. As the days shorten and October's 224 hours approach, one can appreciate how September serves as a bridge, allowing residents and visitors to savor the tail end of summer before the darker months settle in.

Monthly Sunshine Duration in Portrush: September Highlighted

The September sunshine duration represents the total number of hours Portrush 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.
JanFebMarAprMayJunJulAugSepOctNovDec72h146h207h319h405h389h404h357h283h224h117h81h
Data source: Portrush September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Portrush During September

In September, Portrush experiences a 23% chance of sunny weather, which is consistent with the trends seen in the previous months. After a somewhat brighter April at 43%, the likelihood of sunshine dips through the summer with June, July, and August all underperforming with percentages between 19% and 24%. This sets a backdrop of fluctuating sunshine that culminates in the fall months, where October further decreases to 16%. Thus, September serves as a transitional month, offering a glimmer of sun while reminding us that summer is drawing to a close. With its moderate chance of sunny days, September in Portrush invites both locals and visitors to savor the last vestiges of summer before the autumn rains take hold.

Percentage of Sunny Days in September in Portrush

The chart illustrates the percentage of sunny days in Portrush 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 Portrush experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec23%25%15%43%36%22%24%20%23%16%16%14%
Data source: Portrush September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Portrush in September

In September, daylight in Portrush, United Kingdom, reaches a comfortable 12 hours, providing a pleasant transition from the long, sunlit days of summer. As the month unfolds, you can sense a gradual shift in the sunlight as it begins to dwindle compared to the 16 hours enjoyed in May and June. This decrease continues the trend established in late summer, where August offers 14 hours of daylight. The daylight hours begin to shorten more significantly in October, when they drop to 10 hours, marking a clear signal that autumn is upon us. Overall, September balances the remnants of summer brightness with the early whispers of autumn, creating an inviting atmosphere for outdoor activities and contemplation as nature shifts its palette.

Average Daylight Hours in Portrush for September

The chart illustrates the variation in daylight duration in Portrush throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h 49m9h 40m11h 53m14h 10m16h 11m17h 17m16h 41m14h 51m12h 39m10h 24m8h 21m7h 13m
Data source: Portrush daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Portrush

As September arrives in Portrush, the coastal winds begin to shift gears, averaging 5.5 m/s (12 mph). This slight uptick from the languid summer breezes of July and August reflects a gradual reawakening, hinting at the changing seasons. Notably, September’s wind speeds provide a gentle transition as the region gears up for the blusterier months ahead. Historically, these winds are tamer compared to the gusty conditions encountered in the earlier months of the year, with February peaking at an average of 10.5 m/s (23 mph). As autumn approaches, the typical wind pattern hints at the lively November gusts, while still allowing September's charm to linger, making it an ideal time for peaceful coastal strolls against a backdrop of shifting skies.

Average September Wind Speed in Portrush

The chart displays monthly wind speed patterns in Portrush, 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.
JanFebMarAprMayJunJulAugSepOctNovDec7.810.57.55.96.25.73.84.55.5 m/s7.79.38.3
Data source: Portrush September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Portrush Compares to Other Months

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

In September, the weather tends to be milder with average temperatures ranging from a minimum of 9°C (49°F) to a maximum of 17°C (64°F), while January experiences cooler conditions, with average temperatures from a minimum of 2°C (36°F) to a maximum of 13°C (56°F). However, both months are relatively wet, with September receiving 117 mm (4.6 in) of precipitation over 20 days, compared to January's 109 mm (4.3 in) across 17 days. Humidity levels remain high in both months, at around 88% in September and 87% in January. For more specific details about January weather, visit Portrush weather in January.

In September, the weather features milder temperatures with a minimum of 9°C (49°F) and an average of 14°C (57°F), reaching a maximum of 17°C (64°F). The month is quite rainy, with a total precipitation of 117 mm (4.6 in) spread across 20 days and an average humidity of 88%. In contrast, February is considerably cooler, with temperatures ranging from a minimum of 1°C (34°F) to an average of 7°C (44°F) and a maximum of 12°C (54°F). Although February sees slightly higher precipitation at 132 mm (5.2 in) over 18 days, the humidity levels are slightly lower at 86%. For more detailed insights into February weather, you can visit Portrush weather in February.

When comparing the weather in September and March, it's clear that September tends to be milder with average temperatures ranging from a minimum of 9°C (49°F) to a maximum of 17°C (64°F), while March is significantly cooler, with temperatures dropping to a minimum of -1°C (31°F) and peaking at 12°C (54°F). Both months experience substantial precipitation, with September receiving 117 mm (4.6 in) over 20 days, and March slightly lower at 112 mm (4.4 in) over 18 days. Humidity levels are also comparable, with September at 88% and March at 86%. For a closer look at the weather details for March, you can visit Portrush weather in March.

When comparing the weather in September and April, it is evident that September tends to be milder, with average temperatures reaching up to 14°C (57°F), compared to just 8°C (47°F) in April. Additionally, September experiences more precipitation, with 117 mm (4.6 in) over 20 days, whereas April sees only 55 mm (2.2 in) across 12 days. Humidity levels remain fairly similar, with September at 88% and April at 85%. For more detailed insights on April weather in Portrush, you can visit Portrush weather in April.

When comparing the weather in September and May, September tends to be slightly warmer with average temperatures ranging from a minimum of 9°C (49°F) to a maximum of 17°C (64°F). In contrast, May has cooler temperatures, with a minimum of 5°C (41°F) and an average maximum of 16°C (61°F). Additionally, September experiences more rainfall, totaling 117 mm (4.6 in) over 20 days, compared to May's 72 mm (2.9 in) over just 13 days. With humidity levels at 88% in September and 82% in May, the former can feel more damp and cooler despite the warmer average temperature. For more detailed insights into May weather, you can visit Portrush weather in May.

When comparing the weather in September and June, both months exhibit mild temperatures, but September tends to be slightly warmer. September's average temperature reaches 14°C (57°F) with maximum highs of 17°C (64°F), while June has an average of 12°C (54°F) and the same maximum of 17°C (62°F). Precipitation levels are relatively close, with September experiencing slightly more rain at 117 mm (4.6 in) over 20 days compared to June's 105 mm (4.1 in) across 17 days. Additionally, humidity is higher in September at 88%, compared to 84% in June. For more detailed insights, you can check out Portrush weather in June.

In comparing the weather between September and July, it's evident that both months have similar average temperatures, around 14°C (57°F). However, September experiences cooler minimum temperatures, dropping to 9°C (49°F), compared to July's minimum of 11°C (52°F). Additionally, September sees slightly higher precipitation, with 117 mm (4.6 in) falling over 20 days, versus July's 110 mm (4.3 in) over just 17 days. Humidity levels are also a bit higher in September at 88%, compared to July's 86%. For a detailed look at July's weather specifics, check out Portrush weather in July.

In September, the weather begins to cool slightly compared to August, with minimum temperatures dropping to 9°C (49°F) from August's 11°C (52°F). Both months have a similar average temperature of around 14°C (57°F), but September experiences a slightly lower maximum temperature of 17°C (64°F), while August peaks at 18°C (66°F). Precipitation is higher in August, with 146 mm (5.7 in) compared to September's 117 mm (4.6 in), though both months saw rainfall on about 20 days. Humidity levels are also comparable, with September at 88% and August at 86%. For a detailed look at August conditions, check out Portrush weather in August.

In September, temperatures range from a minimum of 9°C (49°F) to a maximum of 17°C (64°F), with an average of 14°C (57°F). The month sees considerable rainfall, totaling 117 mm (4.6 in) over 20 days, accompanied by high humidity levels at 88%. In contrast, October brings cooler temperatures with a minimum of 5°C (42°F) and a maximum of 16°C (62°F), averaging 12°C (53°F). Rainfall increases to 161 mm (6.3 in) over 24 days, and humidity remains slightly elevated at 89%. For a detailed look at October weather, you can check Portrush weather in October.

September tends to be slightly milder than November, with average temperatures ranging from a minimum of 9°C (49°F) to a maximum of 17°C (64°F). In contrast, November experiences cooler temperatures, with an average range of 4°C (40°F) to 14°C (58°F). September also has lower precipitation levels, measuring 117 mm (4.6 in) over about 20 days, while November sees increased rainfall of 156 mm (6.2 in) across 23 days. Additionally, humidity is slightly higher in November at 90%, compared to September's 88%. For more specific details regarding weather conditions, you can refer to Portrush weather in November.

September and December exhibit notable differences in weather patterns. In September, temperatures are milder, with a minimum of 9°C (49°F) and an average of 14°C (57°F), while December sees cooler temperatures, with lows dipping to 2°C (35°F) and an average of 8°C (46°F). Precipitation also increases from 117 mm (4.6 in) in September to 166 mm (6.5 in) in December, with December experiencing more rainy days (23) compared to September's 20. The humidity remains relatively high in both months, at 88% in September and 86% in December. For more specific insights into winter conditions, you can check Portrush weather in December.

Compare Portrush's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Portrush

As September rolls into Portrush, the weather offers a unique transition from the warmth of summer to the cool embrace of autumn. With temperatures averaging around 14°C, visitors can expect a refreshing chill in the air, especially during those brisk mornings and evenings. The month tends to be quite wet, with significant rainfall frequenting about two-thirds of September, reflecting a notable shift in climate compared to the drier months prior. Additionally, the high humidity levels create a distinct coastal feel, making the landscape lush and vibrant. For more insights into how Portrush's weather shapes your visit, explore Portrush Climate.