Last updated: August 27, 2025
September in Porrentruy, Switzerland showcases a delightful blend of warm and cool weather, with maximum temperatures reaching 30°C (86°F) and an average of 15°C (60°F). Although the month brings refreshing changes, including a minimum of 2°C (36°F), outdoor enthusiasts should prepare for 10 days of rain, accumulating 72 mm (2.8 in) of precipitation. With humidity levels hovering around 81%, the atmosphere is often lush and vibrant, making it an ideal time for enjoying the picturesque landscapes of this charming Swiss town.
As September unfolds in Porrentruy, Switzerland, the temperatures begin to reflect the gradual transition from summer to autumn. With minimums hovering around 2°C (36°F) and pleasant averages of 15°C (60°F), the month offers a refreshing ambiance for outdoor exploration. Warm days, with máximas reaching up to 30°C (86°F), remain reminiscent of summer, encouraging locals and visitors alike to soak in the last rays of sunshine before cooler weather sets in. This time of year marks a beautiful balance, leaving behind the scorching highs of summer while gently ushering in the crispness of fall, making it a delightful period for experiencing the charming landscapes of Porrentruy.
In September, Porrentruy experiences a noticeable shift in precipitation patterns, with an average of 72 mm (2.8 in) of rainfall over approximately 10 days. This marks a decline from the wetter summer months, such as May and June, where precipitation levels soared to 144 mm (5.7 in) and 126 mm (5.0 in) respectively. As autumn approaches, the frequency and intensity of rainfall decrease significantly, foreshadowing the drier conditions that will characterize the following months. However, September still retains a certain level of moisture that rejuvenates the scenic landscapes, offering a mild transition into the crispness of fall.
As September rolls into Porrentruy, Switzerland, the air begins to shift, bringing an average humidity of 81%. This slight increase from August's 77% marks a transition towards the cooler months, as the climate gradually embraces the crispness of autumn. Throughout the year, humidity levels exhibit a distinct pattern, peaking at 91% during the winter months of January and December, while dipping to 80% in May. September's humidity reflects a mid-range stability, hinting at the re-emerging dampness typical of the approaching fall. Overall, the gradual fluctuations in humidity capture the essence of Porrentruy’s picturesque seasonal changes, making it a place of refreshing contrasts.
As summer transitions to autumn, September in Porrentruy, Switzerland sees a noticeable dip in the UV Index, which is recorded at 6, placing it in the high exposure category. This means that while the days are still pleasantly bright, the risk of sunburn remains significant, with a recommended burn time of 25 minutes. The sun's intensity, having peaked in the earlier months, particularly in June and July at 9, begins to decline, but it's essential to remain cautious and apply sun protection as you enjoy the lingering warmth of early fall. For more detailed information on UV patterns throughout the year, visit Porrentruy UV Index.
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In Porrentruy, Switzerland, September marks a delightful transition as it basks in an impressive 329 hours of sunshine. Following the sun-drenched months of July and August, which boast 416 and 391 hours respectively, September continues to shine but with a noticeable dip, hinting at the impending autumn. The gentle decline from summer's peak signals a shift in the season, yet this month still offers a generous brightness that lingers long enough for locals and visitors to savor outdoor activities before the cooler days of October, which sees a further drop to 264 hours. As the year progresses, this trend of dwindling sunlight becomes evident, but September's warmth serves as a comforting bridge, wrapping up summer while welcoming the cozy embrace of fall.
In Porrentruy, Switzerland, September marks a notable shift in the weather patterns as the chance of sunny days rises to 44%. This month stands out with a higher likelihood of sunshine compared to the summer peak months of July and August, which hover around the 40% mark. As the warm embrace of summer gives way to the crispness of autumn, September offers a sweet spot for enjoying the outdoors, balancing milder temperatures with an inviting dose of sunshine. Interestingly, this trend signifies a gradual recovery from the dreariness of winter months, where sunny days languish at about 17% in January and only 25% in November. Overall, September presents an enticing opportunity for sun-seekers in Porrentruy, blending the warmth of late summer with the fresh beginnings of fall.
As September unfolds in Porrentruy, Switzerland, the daylight duration begins to wane, providing approximately 12 hours of light each day. This marks a gradual decline from the sun-soaked heights of summer, where June, July, and August bask in a consistent 15 hours of daylight. After reaching its peak, the daylight hours subtly decrease, fitting seamlessly into the seasonal rhythm of the region. Following the vibrant days of late summer, autumn starts to assert its presence, hinting at the shorter days of October and November, which deliver only 10 and 9 hours of daylight, respectively. This transition beautifully captures the essence of changing seasons, offering a dynamic interplay between light and darkness.
As September unfolds in Porrentruy, Switzerland, the average wind speed gently settles at 2.0 m/s (4 mph), marking a noticeable dip as summer transitions into autumn. This month’s breezes are among the lightest of the year, trailing behind the more spirited gusts of late spring and early summer, which peaked at 3.2 m/s (7 mph) in May. Following a gradual decline throughout the summer months, the wind takes on a softer demeanor, creating a serene atmosphere that invites leisurely strolls and reflective moments. As the year progresses towards October, a slight uptick in wind speed is anticipated, suggesting a subtle shift as the landscape prepares for the cooler months ahead.
Weather in Porrentruy varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Porrentruy, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present stark contrasts in weather. In September, temperatures range from a minimum of 2°C (36°F) to a pleasant average of 15°C (60°F), peaking at 30°C (86°F) on warmer days. The month sees moderate precipitation of 72 mm (2.8 in) over about 10 days, with humidity averaging 81%. In contrast, January is much colder, with minimum temperatures dropping to -13°C (8°F) and an average of just 1°C (34°F), while the maximum reaches 14°C (58°F). This winter month experiences higher precipitation at 113 mm (4.4 in) over 13 days, along with a humidity level of 91%. For more details on January weather specifically, you can check out Porrentruy weather in January.
In September, the weather is typically warmer, with average temperatures ranging from a low of 2°C (36°F) to a high of 30°C (86°F). This month experiences around 72 mm (2.8 in) of precipitation over approximately 10 days, and humidity averages at 81%. In contrast, February is much colder, featuring average temperatures that span from a low of -13°C (9°F) up to 18°C (64°F). February also sees higher precipitation levels at 95 mm (3.7 in), occurring over about 12 days, with humidity slightly elevated at 89%. For more specific insights on February weather, you can check Porrentruy weather in February.
In comparing the weather of September and March, we can see some notable differences. September typically enjoys milder temperatures, with a minimum of 2°C (36°F), an average of 15°C (60°F), and a maximum of 30°C (86°F). In contrast, March is much cooler, starting at a minimum of -12°C (10°F) and reaching an average of 6°C (43°F), with a maximum of 21°C (70°F).
Precipitation is also more pronounced in March, accumulating to 108 mm (4.2 in) over about 15 days, while September receives 72 mm (2.8 in) over roughly 10 days. Additionally, humidity levels are slightly higher in March at 87%, compared to 81% in September. For more specific details about March weather, you can refer to Porrentruy weather in March.
When comparing the weather in September and April, it’s evident that September offers warmer temperatures overall, with averages reaching up to 15°C (60°F) and maximums peaking at 30°C (86°F). In contrast, April has a cooler average temperature of 10°C (50°F) and a maximum of 26°C (79°F), with a minimum dipping as low as -4°C (25°F). Both months experience a similar amount of precipitation, with September receiving slightly more at 72 mm (2.8 in) compared to April's 63 mm (2.5 in), yet both have 10 days of rainfall. Humidity levels are quite comparable as well, with September at 81% and April slightly higher at 84%. For a detailed look at April weather, explore Porrentruy weather in April.
In comparing the weather of September and May, both months can have a range of temperatures, but September generally offers slightly warmer conditions. In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 30°C (86°F), with an average of 15°C (60°F). In contrast, May sees temperatures that range from 0°C (32°F) to a high of 30°C (85°F) and an average of 13°C (56°F). However, May experiences significantly higher precipitation, with 144 mm (5.7 in) spread over 17 days compared to September's 72 mm (2.8 in) over 10 days. Both months have high humidity, with September at 81% and May at 80%. For a closer look at the specifics of May weather, you can visit Porrentruy weather in May.
In comparing the weather of September and June, it's evident that June tends to be warmer with average temperatures reaching around 18°C (65°F), compared to September's milder average of 15°C (60°F). June also experiences higher maximum temperatures, peaking at 34°C (93°F), while September's maximum typically reaches 30°C (86°F). However, June sees more precipitation, with 126 mm (5.0 in) over about 16 days, while September has less rain at 72 mm (2.8 in) across 10 days. Both months have similar humidity levels, hovering around 81-82%. For a detailed overview of the weather in June, you can check Porrentruy weather in June.
In September, the weather in Porrentruy sees cooler temperatures, with a minimum of 2°C (36°F) and an average of 15°C (60°F), compared to July's warmer range, which features a minimum of 8°C (46°F) and an average of 20°C (67°F).
While July can heat up to a maximum of 36°C (97°F), September's peak is a more moderate 30°C (86°F). However, September experiences more frequent rainfall with a total precipitation of 72 mm (2.8 in) over approximately 10 rainy days, compared to July's higher 115 mm (4.5 in) spread across 14 days. The humidity levels remain fairly similar, hovering around 81% in September and slightly higher at 82% in July. For a detailed look at July's weather, please check Porrentruy weather in July.
September experiences a notable shift in weather compared to August. While August boasts higher average temperatures, with a minimum of 6°C (43°F) and a maximum of 35°C (95°F), September sees cooler averages, starting at a minimum of 2°C (36°F) and a maximum of 30°C (86°F). Precipitation also decreases in September, totaling 72 mm (2.8 in) over 10 days, compared to 110 mm (4.3 in) across 15 days in August. Humidity remains relatively high in both months, but September's average humidity of 81% is slightly elevated compared to August's 77%. For a closer look at August's conditions, you can explore Porrentruy weather in August.
September and October exhibit a noticeable transition in weather patterns. In September, temperatures range from a mild 2°C (36°F) at night to a warm 30°C (86°F) during the day, with an average of 15°C (60°F). The month experiences less precipitation, totaling 72 mm (2.8 in) over about 10 days, accompanied by relatively high humidity at 81%. In contrast, October brings cooler temperatures, with nighttime lows dipping to -1°C (31°F) and daytime highs reaching 24°C (75°F), averaging around 10°C (51°F). Additionally, October sees an increase in precipitation to 100 mm (3.9 in) spread over 13 days, with humidity rising slightly to 89%. For more detailed information, check out Porrentruy weather in October.
In September, the weather is characterized by relatively warm temperatures, with a minimum of 2°C (36°F) and an average of 15°C (60°F), peaking at a comfortable 30°C (86°F). The month sees around 72 mm (2.8 in) of precipitation over approximately 10 days, and the humidity level is moderately high at 81%. In contrast, November brings a notable drop in temperature, with minimums reaching -3°C (26°F) and an average of just 5°C (41°F). Although the maximum temperature remains a milder 20°C (68°F), the precipitation increases to 88 mm (3.4 in) over 13 days, accompanied by a slightly higher humidity of 89%. For more detailed insights, visit Porrentruy weather in November.
September and December present striking contrasts in weather conditions. In September, temperatures range from a mild 2°C (36°F) at night to a warm 30°C (86°F) during the day, with an average of 15°C (60°F). The month features approximately 72 mm (2.8 in) of precipitation over about 10 days, while humidity levels sit at 81%. In contrast, December experiences much colder temperatures, with nighttime lows plunging to -7°C (20°F) and daytime highs reaching only 13°C (57°F), averaging around 3°C (37°F). Additionally, it sees significantly higher precipitation, totaling 157 mm (6.2 in) across about 20 days, accompanied by even higher humidity levels of 91%. For more detailed information, you can check Porrentruy weather in December.
As September unfolds in Porrentruy, the weather begins to show noticeable shifts, making it a transitional month. Temperatures peak at a warm 30°C, yet the average hovers around a mild 15°C, offering a comfortable escape from the summer heat. Occasional drops to 2°C remind us that autumn is just around the corner. While September brings about a moderate amount of rainfall with ~72 mm spread over about 10 days, the air feels more humid at 81%, creating a refreshing contrast to the drier summer months. This blend of warmth and moisture sets the stage for the vibrant colors and crisp air of fall. For more insights on seasonal changes, explore the Porrentruy Climate.