Last updated: March 17, 2025
September in Portstewart, United Kingdom offers a blend of mild temperatures and damp conditions, making it a month of transition. With a maximum temperature reaching 17°C (64°F) and an average of 14°C (57°F), the weather is generally cool yet pleasant. However, visitors should prepare for wet days, as the town experiences about 117 mm (4.6 in) of rain over 20 days, contributing to a high humidity level of 88%. This mix of cool temperatures and frequent showers creates a unique coastal atmosphere, ideal for those who appreciate the beauty of changing seasons.
In September, Portstewart, United Kingdom, sees a welcomed transition as summer's warmth lingers just a bit longer. With minimum temperatures around 9°C (49°F) and average highs reaching 17°C (64°F), the days remain pleasantly mild, making it a perfect time for outdoor activities. The average temperature of 14°C (57°F) indicates a gradual cooling from the summer months, hinting at the changing seasons ahead. However, compared to the chillier months of January through April, where temperatures often dip below 8°C (46°F), September offers a cozy reprieve that invites visitors to explore the stunning coastal views before autumn fully sets in.
In September, Portstewart experiences a notable increase in precipitation, with 117 mm (4.6 in) of rainfall over 20 days. This marks a transition from the wetter months of late summer, as both August and September feature an uptick in rain days, emphasizing a shift towards the more unpredictable early autumn weather. Interestingly, while July and August also boast significant rainfall, they precede September's consistent dampness, which lays the groundwork for even wetter months ahead. As the landscape begins to shift towards autumn, the patterns of precipitation set the stage for the provocative changes in scenery, making September a month of rich transformation in this coastal region.
In September, Portstewart experiences a notable rise in humidity, reaching 88%, the highest level for the month, which marks a slight increase from the previous summer months. This spike signals the transition into autumn, where moisture levels continue to climb, peaking in October at 89%. The trend of consistently high humidity levels throughout the year highlights Portstewart's maritime climate, with humidity remaining close to the 86-90% range from late summer through winter. As the year progresses, humidity levels fluctuate slightly, but the overall pattern indicates a steady embrace of the damp, invigorating sea air that characterizes this charming coastal town.
As September rolls in Portstewart, the UV Index reflects a gradual transition towards cooler months, sitting at a moderate 5. This shift signals a delightful time for outdoor activities, with a burn time of 30 minutes for unprotected skin. While the intensity decreases from the peak summer months of July and August—both featuring a high UV Index of 6—the early autumn sun still calls for responsible sun safety measures. It's noteworthy that September's UV Index is akin to the levels seen in April, marking a significant drop from the summer's very high ratings. As the days shorten and temperatures fall, remember to stay informed on solar exposure with resources like Portstewart UV Index.
UV Risk Categories
In September, Portstewart basks in a delightful 283 hours of sunshine, offering a warm farewell to summer. This month continues the trend of decreasing sunlight that began in late summer, following July's peak at 404 hours and August's respectable 357 hours. Despite the shorter days, September still retains a generous amount of sunshine compared to the chillier months that follow, such as October with just 224 hours. As the warm glow of summer begins to dim, the vibrant autumn colors emerge, making this a perfect time to enjoy the beauty of the coast while soaking up the last rays of the season.
September in Portstewart, United Kingdom, sees a 23% chance of sunny weather, which is consistent with the trends observed throughout the year. As summer transitions to autumn, the likelihood of sunshine dips slightly from the warmer months, mirroring the patterns in July and August. However, this percentage stands in stark contrast to the high points of spring, particularly April, which boasts a notable 43% chance of sun. Comparatively, September maintains a moderate sunny outlook, aligning closely with the winter months of January and February. Overall, while the sun may not always shine in September, it offers a gentle continuation of summer's warmth before the chill of autumn sets in.
As summer bids farewell, September in Portstewart, United Kingdom, marks a gentle transition into autumn with an average daylight duration of 12 hours. Following the sun-drenched months of May and June, which boasted up to 17 hours of daylight, this month's light begins to recede gradually. By September, the brightness still lingers, offering a comfortable balance between warmth and the gradual chill of approaching fall. The daylight hours start declining more steeply in October and November, hinting at the shorter days ahead, yet September's soft glow serves as a splendid farewell to the vibrant hues of summer, allowing residents and visitors alike to enjoy the beauty of the changing seasons.
As summer fades into autumn, September in Portstewart brings a gentle breeze with an average wind speed of 5.5 m/s (12 mph). This marks a subtle increase from the tranquil winds of July and August, which are typically calmer at 3.8 m/s (8 mph) and 4.5 m/s (10 mph) respectively. Leading into the more blustery months of October and November, where winds pick up to 7.7 m/s (17 mph) and 9.3 m/s (21 mph), September serves as a bridge, offering a comfortable transition. The overall trend showcases a gradual escalation in wind speed as the year progresses, hinting at the impending shift in seasonal dynamics. Whether it’s a leisurely walk along the coast or a day spent exploring, September's winds provide a refreshing reprieve, setting the stage for the more robust gusts that lie ahead.
The weather in Portstewart 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 Portstewart and find detailed weather information for every month.
In September, the weather is notably 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 averages between 2°C (36°F) and 13°C (56°F). Despite both months having a similar level of precipitation—117 mm (4.6 in) in September and 109 mm (4.3 in) in January—September tends to experience more rainy days (20) compared to January's 17 days. Humidity levels are quite comparable, with September at 88% and January slightly lower at 87%. For more details on January weather, you can check Portstewart weather in January.
When comparing the weather in September and February, 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). February, on the other hand, is colder with average temperatures between 1°C (34°F) and 12°C (54°F). Precipitation levels are relatively high in both months, with September receiving 117 mm (4.6 in) over 20 days, while February sees slightly more at 132 mm (5.2 in) across 18 days. Humidity levels are also comparable, with September at 88% and February at 86%. For a detailed look at the weather specifics for February, you can check Portstewart weather in February.
When comparing the weather in September and March, it's clear that September generally offers milder temperatures, with averages around 14°C (57°F) compared to March's cooler average of 7°C (45°F). While September experiences temperatures that peak at 17°C (64°F), March's maximum is only 12°C (54°F). Both months see significant rainfall, with September recording 117 mm (4.6 in) over 20 days and March closely following with 112 mm (4.4 in) over 18 days. Humidity levels are relatively high in both months, slightly higher in September at 88% compared to March's 86%. For more detailed information, you can check out the Portstewart weather in March.
When comparing the weather in September and April, notable differences emerge in temperature and precipitation. September experiences milder conditions with average temperatures ranging from 9°C (49°F) to 17°C (64°F), while in April, temperatures are cooler, averaging between 2°C (36°F) and 13°C (56°F). Additionally, September is wetter, with 117 mm (4.6 in) of rainfall over 20 days, compared to April's 55 mm (2.2 in) over 12 days. Both months have high humidity levels, but September's average of 88% slightly exceeds April's 85%. For a closer look at April conditions in Portstewart, you can visit Portstewart 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 experiences cooler temperatures, with a minimum of 5°C (41°F) and an average high of 16°C (61°F). September is also characterized by more precipitation, averaging 117 mm (4.6 in) over 20 days, compared to May's 72 mm (2.9 in) over 13 days. Additionally, the humidity levels are higher in September at 88%, compared to 82% in May. For a more detailed look at May weather in Portstewart, visit Portstewart weather in May.
In comparing the weather between September and June, both months feature similar maximum temperatures, peaking at around 17°C (64°F). However, September has a slightly higher average temperature of 14°C (57°F) compared to June's 12°C (54°F). Rainfall levels in September are also more substantial, with 117 mm (4.6 in) recorded over 20 days, compared to June’s 105 mm (4.1 in) over 17 days. Additionally, September tends to be more humid, with a humidity level of 88% versus June's 84%. For a more detailed look at June weather, you can visit Portstewart weather in June.
In comparing the weather between September and July, September tends to exhibit slightly cooler temperatures, with a minimum of 9°C (49°F) compared to July’s minimum of 11°C (52°F). Both months have similar average temperatures of 14°C (57°F), but July reaches a higher maximum of 19°C (67°F) versus September's maximum of 17°C (64°F). Rainfall is relatively consistent, with September receiving 117 mm (4.6 in) across 20 days, while July sees 110 mm (4.3 in) over 17 days. Humidity is slightly higher in September at 88%, compared to July’s 86%. For a more detailed look at July's weather, you can check Portstewart weather in July.
Comparing the weather in September to that of August reveals some notable differences and similarities. September features slightly cooler temperatures, with a minimum of 9°C (49°F) and a maximum of 17°C (64°F), compared to August's minimum of 11°C (52°F) and maximum of 18°C (66°F). Both months experience similar average temperatures, around 14°C (57°F) for September and 14°C (58°F) for August. However, September sees an increase in precipitation, totaling 117 mm (4.6 in) over 20 days, compared to August's 146 mm (5.7 in) over the same number of days. Humidity levels also remain high in both months, with September slightly higher at 88%, compared to August's 86%. For a detailed look at August's weather, you can check Portstewart weather in August.
In comparing the weather between September and October, we observe a noticeable shift in temperatures and precipitation patterns. September starts with mild temperatures, featuring a minimum of 9°C (49°F) and an average of 14°C (57°F), while October sees a slight drop, with minimum temperatures reaching 5°C (42°F) and an average of 12°C (53°F). Rainfall increases in October, totaling 161 mm (6.3 in) over 24 days, compared to September's 117 mm (4.6 in) spread over 20 days. Humidity remains relatively consistent, with September at 88% and October just a touch higher at 89%. For a more detailed look at October's climate, check out Portstewart weather in October.
In September, the weather generally sees milder temperatures with a minimum of 9°C (49°F) and an average of 14°C (57°F), peaking at a maximum of 17°C (64°F). Rainfall is frequent, occurring on about 20 days and totaling 117 mm (4.6 in), with humidity levels around 88%. In contrast, November brings cooler conditions, with temperatures dropping to a minimum of 4°C (40°F) and an average of 9°C (49°F), while the maximum reaches only 14°C (58°F). The month records increased precipitation at 156 mm (6.2 in) over 23 days, coupled with slightly higher humidity at 90%. For more detailed insights, check out Portstewart weather in November.
September and December present distinctly different weather conditions. 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). This month experiences an average precipitation of 117 mm (4.6 in) over 20 days, accompanied by high humidity at 88%. In contrast, December sees lower temperatures, with a minimum of 2°C (35°F) and a maximum of 12°C (54°F), averaging 8°C (46°F). Additionally, precipitation increases to 166 mm (6.5 in) across 23 days, while humidity levels remain relatively high at 86%. For more specifics about December weather in Portstewart, you can check out Portstewart weather in December.
As September arrives in Portstewart, the weather begins a gentle transition, offering a cooler and often wetter experience compared to the summer months. With average temperatures dipping down to a refreshing 14°C and an increase in humidity to 88%, the coastal charm of this town is accentuated by the soft mists and frequent rain showers. With 20 days of precipitation, it's a month where visitors should be prepared for the unpredictable nature of the elements. Embracing this shift can reveal the stunning autumn landscapes and unique coastal beauty that only September can offer. For more detailed insights, check out the Portstewart Climate.