September Weather in Arinsal, Andorra

Last updated: August 25, 2025

September in Arinsal, Andorra, showcases the transition from summer to autumn with maximum temperatures reaching 23°C (74°F) and an average of 11°C (52°F). As the month progresses, a drop to minimum temperatures of -3°C (27°F) hints at the impending chill of winter. While the beauty of this alpine locale is complemented by a humidity level of 73%, it also experiences about 70 mm (2.8 in) of rain over approximately 12 days, inviting visitors to enjoy the vibrant fall foliage amidst scattered showers. Whether you're hiking through picturesque landscapes or simply soaking in the stunning views, September's weather in Arinsal offers a unique experience filled with both warmth and refreshing coolness.

September Temperature in Arinsal

In September, Arinsal, Andorra transitions into a mild autumn, offering a refreshing respite from the summer's warmth. With minimum temperatures around -3°C (27°F), the air begins to crisp, while daily averages settle at a comfortable 11°C (52°F). The daytime peaks can reach up to 23°C (74°F), making it an ideal time for outdoor enthusiasts to enjoy the breathtaking landscapes. This month marks a significant shift from the summer highs of July and August, but it's still pleasantly balmy compared to the chill of the upcoming winter months, hinting at the seasonal changes ahead. Overall, September presents a delightful balance of warmth and coolness, inviting visitors to savor the beauty of Arinsal before the snow arrives.

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

The chart illustrates September temperature patterns in Arinsal, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Arinsal, September typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec273234384655595952453330
Data source: Temperature data for Arinsal 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 Arinsal

In September, Arinsal, Andorra experiences a moderate precipitation level of 70 mm (2.8 in), falling within the trend of early autumn. This month typically sees 12 days of rain, comparable to the previous months of July and August, which recorded 10 and 12 days, respectively. As the region transitions from the summer warmth, this slight decrease in rainfall from the peak wet months of May and June—where precipitation reached 111 mm (4.4 in) and 115 mm (4.5 in)—signals the onset of a more pronounced autumnal climate. Overall, September's rainfall patterns encourage a gradual cooling and set the stage for the crisp conditions that follow in October and the winter months ahead.

September Precipitation Trends in Arinsal

The chart displays monthly precipitation patterns in Arinsal, 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. In Arinsal, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec76608793111115657870858693
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Arinsal

In September, Arinsal, Andorra experiences a mild increase in humidity, reaching 73%. This level provides a comfortable balance as summer transitions into autumn, following a gradual decline from the high humidity of the earlier months. During the summer, humidity dipped to its lowest point in July at 72% and August at 70%. As the crispness of fall approaches, humidity levels rise slightly in September but remain lower than the winter months, which typically see a spike, reaching 88% in December. This trend illustrates a seasonal rhythm, where autumn brings a gentle rise in moisture, preparing the landscape for the wetter months ahead.

September Average Humidity in Arinsal

This chart illustrates the average monthly humidity levels in Arinsal, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Arinsal is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%83%80%77%75%74%72%70%73%82%87%88%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Arinsal

September in Arinsal, Andorra, sees a UV Index of 8, classified as very high, requiring careful sun protection for outdoor enthusiasts. As summer transitions to fall, the UV levels begin to taper off, although they still pose a significant risk. With a burn time of just 15 minutes, it’s essential to be proactive about sun safety during this month. This trend of decreasing UV intensity from the peak of summer is evident, moving from a scorching 11 in July to 8 in September. The higher indices earlier in the year culminate in a sharp rise in sun exposure awareness, reminding visitors that even as temperatures cool, sun safety remains paramount. For more insights on the UV levels this month, check out Arinsal UV Index.

Maximum UV Index Levels in Arinsal for September

The chart shows the monthly maximum UV Index (UVI) for Arinsal 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. In September, the maximum UV index in Arinsal typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3468101111108642
Data source: Arinsal 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 Arinsal

September in Arinsal, Andorra, shines with an impressive 343 hours of sunshine, marking a slight dip from the vibrant summer months but still holding its charm. The warm glow of late summer lingers, as this month transitions into the crisp autumn air. With a gradual decline from the peak of 427 hours in July and 397 hours in August, September offers a delightful balance of sunny days perfect for outdoor adventures. While the daylight wanes in the following months, the tail end of summer ensures visitors can still bask in pleasant weather, making it an ideal time to explore the stunning landscapes of Arinsal.

Monthly Sunshine Duration in Arinsal: September Highlighted

The September sunshine duration represents the total number of hours Arinsal 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.
JanFebMarAprMayJunJulAugSepOctNovDec201h260h329h342h398h412h427h397h343h306h260h255h
Data source: Arinsal September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Arinsal During September

As September rolls into Arinsal, Andorra, the likelihood of basking in sunny weather takes a notable dip, with only a 21% chance of sunshine. This marks a significant decline from the summer months of July and August, which enjoy peak sunshine at 45% and 46%, respectively. The transition into fall brings a blend of cooler temperatures and increased cloud cover, making September one of the less favorable months for sun-seekers in this picturesque mountainous region. However, as the season shifts, outdoor enthusiasts can still revel in Arinsal's stunning landscapes, with the potential for clear days amidst the changing foliage.

Percentage of Sunny Days in September in Arinsal

The chart illustrates the percentage of sunny days in Arinsal 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 Arinsal experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec28%32%41%33%21%37%45%46%21%42%29%42%
Data source: Arinsal September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Arinsal in September

As summer transitions into autumn, September in Arinsal, Andorra offers a delightful 12 hours of daylight. This marks a gradual decrease from the peak 15 hours enjoyed in June, highlighting how swiftly nature shifts its rhythms. The lingering warmth of early autumn still allows for ample opportunities to savor the outdoors, but as daylight gradually wanes towards October’s 11 hours, it signifies the impending embrace of winter. The consistent ebb and flow of daylight throughout the year reflects not only the changing seasons but also invites residents and visitors alike to relish the vibrant outdoor activities unique to this enchanting alpine locale.

Average Daylight Hours in Arinsal for September

The chart illustrates the variation in daylight duration in Arinsal throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 26m10h 33m11h 57m13h 23m14h 37m15h 14m14h 54m13h 49m12h 26m11h9h 44m9h 5m
Data source: Arinsal daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Arinsal

As the summer warmth begins to fade, September in Arinsal showcases a gentler breeze, with an average wind speed of 1.4 m/s (3 mph). This gradual decrease from the earlier peak summer months hints at the transition into autumn, marked by cooler temperatures and serene landscapes. Interestingly, the trend reveals a consistent decline in wind speeds from August through September, reaching its annual low before slightly picking up again in October. This subtle lull invites visitors to savor the crisp mountain air and the stunning fall foliage, making it an ideal time for leisurely hikes and enjoying the tranquil beauty of Andorra's nature.

Average September Wind Speed in Arinsal

The chart displays monthly wind speed patterns in Arinsal, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.02.01.91.71.61.71.71.51.4 m/s1.61.91.7
Data source: Arinsal September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Arinsal Compares to Other Months

Weather in Arinsal varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Arinsal, focusing on differences in temperature, rainfall, humidity, and UV levels.

In September, the weather in Arinsal presents a mild transition into autumn, with average temperatures ranging from a minimum of -3°C (27°F) to a maximum of 23°C (74°F). While the temperature is generally comfortable, the month sees about 70 mm (2.8 in) of rainfall over approximately 12 days, with a humidity level of 73%. In contrast, January experiences a significant drop in temperatures, with averages sitting between -20°C (-3°F) and a peak of just 10°C (51°F). This colder month brings slightly more precipitation at 76 mm (3.0 in) across 9 days, along with a higher humidity level of 87%. For a detailed look at January weather patterns, you can check Arinsal weather in January.

In comparing the weather between September and February, we see notable differences in temperature and overall conditions. September experiences milder temperatures with a minimum of -3°C (27°F) and an average of 11°C (52°F), reaching a maximum of 23°C (74°F), while February is significantly colder, featuring a minimum of -15°C (5°F) and an average of 0°C (33°F) with a maximum of only 12°C (55°F). Precipitation levels are fairly similar, with September receiving about 70 mm (2.8 in) over 12 days, compared to February's 60 mm (2.4 in) over 10 days. Furthermore, humidity is slightly higher in February at 83%, compared to September's 73%. For more specific insights on February conditions in this region, you can refer to Arinsal weather in February.

When comparing the weather in September and March, several key differences emerge. September tends to be milder, with average temperatures around 11°C (52°F) and maximums reaching 23°C (74°F), while March remains quite chilly, averaging just 1°C (34°F) with maximums of 15°C (59°F). Precipitation levels are relatively high in both months, but March sees slightly more at 87 mm (3.4 in) over 14 days compared to September's 70 mm (2.8 in) over 12 days. Furthermore, humidity is higher in March at 80% compared to September's 73%, contributing to a colder and wetter feel during late winter. For a detailed outlook, you can refer to Arinsal weather in March.

In comparing the weather of September and April, September tends to be milder with average temperatures ranging from a chilly -3°C (27°F) at night to a pleasant 23°C (74°F) during the day. It experiences 70 mm (2.8 in) of precipitation over approximately 12 days, coupled with a humidity level of 73%. In contrast, April is cooler, with a minimum temperature of -12°C (10°F), an average of 3°C (38°F), and a maximum of 15°C (59°F). April sees slightly higher precipitation at 93 mm (3.7 in) across 13 days and a humidity of 77%. For those interested in more detailed information, check out Arinsal weather in April.

When comparing the weather in September to that in May, several differences become apparent. In September, temperatures range from a minimum of -3°C (27°F) to a maximum of 23°C (74°F), with an average of 11°C (52°F). The precipitation levels are relatively moderate at 70 mm (2.8 in) over about 12 days, and humidity sits at 73%. In contrast, May presents cooler conditions, with temperatures ranging from a minimum of -9°C (17°F) to a maximum of 22°C (72°F) and an average temperature of 8°C (46°F). Moreover, May experiences higher precipitation at 111 mm (4.4 in), spread across 19 days, while humidity is slightly higher at 75%. For more details on the weather in May, you can visit Arinsal weather in May.

Comparing the weather in September and June reveals notable differences. In September, temperatures range from a chilly minimum of -3°C (27°F) to a comfortable maximum of 23°C (74°F), with an average of 11°C (52°F). In contrast, June sees slightly warmer conditions, with a minimum of -3°C (26°F) and a maximum reaching 28°C (82°F), averaging 13°C (55°F). Precipitation is more pronounced in June, totaling 115 mm (4.5 in) over 15 days compared to September's 70 mm (2.8 in) across 12 days. Humidity levels are quite similar, hovering around 73% for September and 74% for June. For more detailed information on June weather in Arinsal, you can check Arinsal weather in June.

In comparing the weather between September and July, September tends to be cooler with minimum temperatures dropping to -3°C (27°F) compared to July's minimum of 2°C (37°F). The average temperature in September is 11°C (52°F), while in July it is noticeably warmer at 15°C (60°F). Both months have similar precipitation levels, with September receiving 70 mm (2.8 in) over approximately 12 days and July slightly less at 65 mm (2.6 in) across 10 days. Humidity levels remain quite consistent, with September at 73% and July at 72%. For a detailed overview, you can check Arinsal weather in July.

In August, the weather typically features warmer temperatures, with averages around 15°C (60°F) and maximums reaching 27°C (81°F). In contrast, September sees a decrease in warmth, with average temperatures dropping to 11°C (52°F) and max temperatures peaking at 23°C (74°F). Despite both months experiencing around 12 days of precipitation, September has slightly reduced rainfall at 70 mm (2.8 in) compared to August's 78 mm (3.1 in). Humidity levels are also similar, with August at 70% and September slightly higher at 73%. For a closer look at how summer in Arinsal varies, check out Arinsal weather in August.

As September transitions into October, there is a noticeable drop in temperatures, with October experiencing a minimum of -13°C compared to September's minimum of -3°C. While the average temperature in September is a milder 11°C, October sees a further decrease to an average of 7°C. Both months are relatively wet, but October has slightly higher precipitation at 85 mm over 9 days, compared to September’s 70 mm over 12 days. Additionally, humidity levels rise in October to 82%, compared to 73% in September, contributing to a much cooler and damp feel as autumn progresses. For more detailed information, you can check out Arinsal weather in October.

In September, temperatures range from a chilly minimum of -3°C (27°F) to a pleasant maximum of 23°C (74°F), with an average of 11°C (52°F). The month sees about 70 mm (2.8 in) of precipitation over 12 days, and humidity levels average around 73%. In contrast, November brings colder conditions, featuring a minimum temperature of -14°C (6°F) and a much lower average of just 1°C (33°F), peaking at 16°C (61°F). Precipitation increases to 86 mm (3.4 in) over 13 days, and humidity rises to 87%. For a closer look at what to expect, check out Arinsal weather in November.

September and December present notable contrasts in weather conditions. In September, temperatures vary from a minimum of -3°C (27°F) to a maximum of 23°C (74°F), with an average of 11°C (52°F) and a relatively moderate humidity of 73%. Precipitation is also less intense, totaling 70 mm (2.8 in) over 12 days. Conversely, December boasts colder temperatures, with a minimum of -14°C (6°F) and an average of -1°C (30°F), peaking at 11°C (52°F). The month is characterized by increased precipitation of 93 mm (3.7 in) over the same number of days, coupled with higher humidity at 88%. For more details, check out Arinsal weather in December.

Compare Arinsal's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Arinsal

September in Arinsal offers a gentle transition from the warm summer months to the crispness of autumn. With average temperatures settling around 11°C (52°F), it’s noticeably cooler than the peak summer heat, yet still enjoys a few warm days where temperatures can reach up to 23°C (74°F). However, nighttime chill can dip as low as -3°C (27°F), making it a month to prepare for the changing seasons. The increased precipitation, with around 70 mm (2.8 in) over approximately 12 days, also sets September apart, hinting at the upcoming fall. With a humidity level of 73%, the air carries a hint of freshness, perfect for enjoying the stunning landscapes. For a deeper look at how Arinsal's weather evolves throughout the year, check out Arinsal Climate.