September Weather in Locarno, Switzerland

Last updated: August 27, 2025

September in Locarno, Switzerland is characterized by a mild climate, with maximum temperatures reaching a pleasant 23°C (74°F) and an average of 13°C (55°F). As the month unfolds, temperatures can dip to a brisk minimum of -1°C (31°F), reminding visitors that autumn is on the horizon. The area experiences substantial rainfall, totaling 136 mm (5.4 in) across 14 days, contributing to the lush landscapes. Humidity levels hover around 83%, creating a refreshing atmosphere that enhances the charm of this picturesque location during early fall.

September Temperature in Locarno

As September rolls into Locarno, Switzerland, the summer warmth begins to wane, making way for the crispness of autumn. **Temperatures during this month typically range from a cool -1°C (31°F) at night to a pleasant 23°C (74°F) during the day, with an average temperature settling around 13°C (55°F). This transition marks a notable shift from the higher summer highs, yet it still offers ample opportunities for outdoor activities amid the stunning fall foliage. The gradual dip in temperatures from August's warmth to September's mildness sets the perfect backdrop for exploring this picturesque lakeside town while enjoying its serene ambiance.

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

The chart illustrates September temperature patterns in Locarno, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Locarno, 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).
JanFebMarAprMayJunJulAugSepOctNovDec293337445160626255473731
Data source: Temperature data for Locarno 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 Locarno

In September, Locarno experiences a significant blend of rainfall, tallying 136 mm (5.4 in) over approximately 14 days. This marks a continuation of the wet trend seen throughout the summer months, especially following August's 169 mm (6.6 in). Notably, September's precipitation is slightly lower than both May and April, yet it maintains a robust level, reflecting the region's transition into the more temperate fall season. As the year progresses into October, precipitation surges dramatically with an expected 242 mm (9.5 in), underscoring a notable seasonal shift. The relatively consistent number of precipitation days hints at a steady rhythm of rain, characteristic of Locarno's lush environment.

September Precipitation Trends in Locarno

The chart displays monthly precipitation patterns in Locarno, 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 Locarno, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec7156106136176159124169136242168119
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Locarno

In September, Locarno experiences a moderate humidity level of 83%, a slight increase from the summer months. This level reflects a trend where humidity begins to stabilize after the warmer season's fluctuations, settling just above the late summer average of 80%. Following a gradual decline from January's peak of 92%, September's figures indicate that while the air remains comfortably humid, the crispness of autumn is on the horizon. As the year transitions into October, humidity will rise again to 90%, emphasizing the distinct shifts in Locarno’s climatic rhythm. Overall, September serves as a bridge between the warm embrace of summer and the coolness of autumn, inviting residents and visitors to enjoy the beauty of this serene lakeside town.

September Average Humidity in Locarno

This chart illustrates the average monthly humidity levels in Locarno, 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 Locarno is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec92%89%87%84%80%82%83%80%83%90%89%90%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Locarno

As summer fades into autumn, September in Locarno, Switzerland, sees a notable shift in the UV Index, reaching a high level of 7. While this marks a decrease from the intense 10 witnessed in July and June, sun-seekers should remain vigilant, as the burn time is still a swift 25 minutes. This transitional month illustrates a consistent pattern, where UV exposure diminishes as temperatures cool, yet the potential for sunburn remains significant. As you enjoy the beautiful autumn landscapes, it's essential to stay informed. For detailed insights, check the Locarno UV Index.

Maximum UV Index Levels in Locarno for September

The chart shows the monthly maximum UV Index (UVI) for Locarno 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 Locarno typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec24689101097532
Data source: Locarno 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 Locarno

As summer gracefully transitions into autumn, September in Locarno, Switzerland, offers a splendid farewell to the warm season with 302 hours of sunshine. This month's sun-drenched days follow a peak in July, when the region basks in an impressive 404 hours of sunlight. While September slips into shorter days compared to the sun-soaked summer months, it still holds on to a generous amount of sunshine, outshining the gloomy months that follow. With an average of over 300 hours, September perfectly captures the essence of blossoming fall, inviting visitors to savor its vibrant landscapes and pleasant weather before winter subtly creeps in.

Monthly Sunshine Duration in Locarno: September Highlighted

The September sunshine duration represents the total number of hours Locarno 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.
JanFebMarAprMayJunJulAugSepOctNovDec174h225h301h330h350h379h404h362h302h265h194h193h
Data source: Locarno September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Locarno During September

In September, Locarno experiences a 35% chance of sunny weather, representing a slight dip compared to the summer months of June and August, where the likelihood peaks at 33% and 50%, respectively. This trend suggests that while outdoor enthusiasts may still enjoy some sun-drenched days, the transition into autumn brings a gradual reduction in brightness. Furthermore, September's sunniness is notably higher than the chillier winter months, which hover around 31% to 40%. As the season shifts, those seeking sun may want to plan ahead, embracing the lingering warmth while it lasts.

Percentage of Sunny Days in September in Locarno

The chart illustrates the percentage of sunny days in Locarno 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 Locarno experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec31%40%58%46%38%33%37%50%35%44%40%46%
Data source: Locarno September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Locarno in September

As the summer days gracefully transition into autumn, September in Locarno, Switzerland, boasts a vibrant 12 hours of daylight. This marks a gentle decline from the sun-soaked 15 hours enjoyed in July and August, reflecting the gradual shift of the seasons. The daylight duration begins to taper, leading us towards the cozy embrace of October with its 10 hours of light. The trend of increasing daylight from winter’s depths, peaking mid-year, sets the stage for the subtle retreat into shorter days. As September unfolds, residents and visitors alike can revel in the rich, golden hues of the early autumn sun before the days further diminish towards winter's arrival.

Average Daylight Hours in Locarno for September

The chart illustrates the variation in daylight duration in Locarno throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 4m10h 20m11h 56m13h 34m14h 58m15h 41m15h 18m14h 4m12h 29m10h 52m9h 25m8h 40m
Data source: Locarno daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Locarno

As September rolls in, Locarno, Switzerland, experiences a gentle breeze averaging 1.2 m/s (3 mph), slightly calmer than the summer months. This subtle drop in wind speed reflects the transition from the vibrant energy of summer to the tranquil embrace of early autumn. The winds, which were consistently 1.3 m/s (3 mph) in the preceding months, taper off, creating a serene atmosphere perfect for leisurely strolls along the lake or enjoying the picturesque landscapes. As the season shifts, one can anticipate the gradual uptick in wind speeds in the following months, hinting at the invigorating crispness of October and November ahead, yet for now, September's mild winds invite reflection and relaxation in this enchanting Swiss locale.

Average September Wind Speed in Locarno

The chart displays monthly wind speed patterns in Locarno, 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.
JanFebMarAprMayJunJulAugSepOctNovDec1.71.21.41.31.41.21.31.31.2 m/s1.41.62.0
Data source: Locarno September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Locarno Compares to Other Months

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

September and January exhibit stark differences in weather conditions. September enjoys a milder temperature range, with averages around 13°C (55°F) and maximums reaching 23°C (74°F), contrasted by January’s frigid climate where temperatures can drop as low as -16°C (4°F) and average only -2°C (29°F). With October's average humidity at 83%, September feels more comfortable, while January's humidity peaks at 92%, adding to the chill. Rainfall is also higher in September, with 136 mm (5.4 in) over 14 days, compared to January's 71 mm (2.8 in) across 10 days. For a detailed look at January's conditions, explore Locarno weather in January.

When comparing the weather in September and February, a marked difference in temperatures and conditions can be observed. September typically experiences milder temperatures with a minimum of -1°C (31°F) and an average of 13°C (55°F), peaking at 23°C (74°F). In contrast, February is significantly colder, with temperatures ranging from a minimum of -17°C (2°F) to a maximum of 17°C (63°F), resulting in an average of just 1°C (34°F).

Additionally, September sees higher precipitation, totaling 136 mm (5.4 in) over 14 days, while February is drier with only 56 mm (2.2 in) over 11 days. Despite February’s lower rainfall, the humidity remains high at 89%, slightly more than September's 83%. For a closer look at February's weather in Locarno, check out Locarno weather in February.

September and March present contrasting weather patterns. In September, temperatures range from a minimum of -1°C (31°F) to a maximum of 23°C (74°F), with an average of 13°C (55°F). The month experiences significant precipitation, totaling 136 mm (5.4 in) over 14 days, and humidity levels are relatively high at 83%. In contrast, March is colder, with temperatures varying from -17°C (3°F) to a maximum of 18°C (64°F), and an average of just 3°C (37°F). Although March has slightly lower precipitation at 106 mm (4.2 in) over 12 days, humidity remains high at 87%. For a detailed look at March weather, visit Locarno weather in March.

When comparing September and April weather, we observe notable differences in temperature and conditions. September features a more temperate climate with average temperatures ranging from a cool 13°C (55°F) to a warm 23°C (74°F), while April is cooler, with average temperatures between -6°C (21°F) and 20°C (68°F). Both months experience similar levels of precipitation, around 136 mm (5.4 in) in September and 136 mm (5.3 in) in April, though September sees rainfall over 14 days compared to April's 10 days. Humidity levels are also comparable, with September at 83% and April slightly higher at 84%. For more detailed insights on April weather, you can visit Locarno weather in April.

In comparing the weather of September and May, we observe some intriguing contrasts. September tends to be warmer on average, with temperatures ranging from a minimum of -1°C (31°F) to a maximum of 23°C (74°F), while May has a slightly lower average temperature, swinging between -7°C (21°F) and 25°C (77°F). Precipitation is notably higher in May, totaling 176 mm (6.9 in) over 19 days compared to September's 136 mm (5.4 in) across 14 days. Additionally, September's humidity is slightly higher at 83%, while May maintains a mild 80%. For more detailed insights, visit Locarno weather in May.

In comparing the weather between September and June, September tends to be cooler, with average temperatures ranging from a minimum of -1°C (31°F) to a maximum of 23°C (74°F), while June enjoys warmer temperatures that range from a low of 5°C (41°F) to a high of 34°C (93°F). Both months experience significant precipitation, with September receiving 136 mm (5.4 in) over approximately 14 days and June slightly wetter at 159 mm (6.3 in) across 18 days. Interestingly, humidity levels remain similar, with September at 83% and June at 82%. For a closer look at the specifics of June weather, you can check Locarno weather in June.

In comparing the weather between July and September, it's clear that July tends to be warmer, with average temperatures reaching 17°C (63°F) and maximums up to 27°C (80°F), while September sees cooler averages at 13°C (55°F) and maximums only reaching 23°C (74°F). Both months experience high humidity levels of 83%, but precipitation is slightly more frequent in September with 14 days of rain compared to 18 days in July. Interestingly, September also records more rainfall overall, measuring 136 mm (5.4 in) versus July's 123 mm (4.9 in). For further details, check out Locarno weather in July.

In comparing the weather of September and August, we see a notable shift in temperatures and precipitation patterns. September experiences cooler conditions, with average temperatures ranging from a minimum of -1°C (31°F) to a maximum of 23°C (74°F), compared to August's milder range of 7°C (45°F) to 28°C (82°F). Additionally, September has a higher total precipitation of 136 mm (5.4 in) over 14 days, while August, despite having slightly more precipitation at 169 mm (6.6 in), spans just 13 rain days. Humidity levels in September are slightly higher at 83% compared to August's 80%. For more details, check out Locarno weather in August.

September and October exhibit notable differences in weather patterns. In September, temperatures range from a low of -1°C (31°F) to a high of 23°C (74°F), with an average temperature of 13°C (55°F). The month sees a total precipitation of 136 mm (5.4 in) over 14 days and maintains a humidity level of 83%. In contrast, October experiences slightly cooler temperatures, with a minimum of -1°C (30°F), an average of 8°C (47°F), and a maximum of 21°C (69°F). Rainfall increases significantly in October, reaching 242 mm (9.5 in) over just 12 days, and humidity rises to 90%. For more detailed information about the weather in October, you can check Locarno weather in October.

September's weather offers a milder charm with average temperatures around 13°C (55°F) and maximums reaching 23°C (74°F), making it a comfortable transition into autumn. However, as the month progresses, it sees significant rainfall, with 136 mm (5.4 in) falling over 14 days, and humidity remains high at 83%. In contrast, November brings a notable chill, with average temperatures dropping to 3°C (38°F) and nighttime lows plunging to -9°C (16°F). Although it is slightly wetter than September, with 168 mm (6.6 in) of precipitation over 13 days, the humidity climbs to 88%. For more details on the weather in November, visit Locarno weather in November.

In September, the weather is notably milder, with temperatures ranging from a minimum of -1°C (31°F) to a maximum of 23°C (74°F) and an average temperature of 13°C (55°F). The month experiences a considerable amount of precipitation, totaling 136 mm (5.4 in) over 14 days, along with humidity levels around 83%.

In contrast, December's temperatures drop significantly, with a minimum of -13°C (10°F) and a maximum of 9°C (49°F), resulting in an average temperature of -1°C (31°F). Despite slightly lower overall precipitation at 119 mm (4.7 in) over 12 days, humidity rises to 90%, creating a colder and more damp atmosphere. For more insights into December weather, you can visit Locarno weather in December.

Compare Locarno's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Locarno

In September, Locarno begins to transition from the warm summer days, showcasing a delightful mix of mild temperatures and refreshing cooling breezes. While the maximum daytime heat can reach a comfortable 23°C, the nights can chill down to 1°C, offering a striking contrast that sets this month apart from the sweltering summer months that precede it. Rainfall is frequent, with approximately half the month experiencing precipitation, which contributes to the lushness of the surrounding landscapes. With an average humidity of 83%, September maintains a certain freshness in the air that is less prevalent in the hot summer months. For a deeper understanding of seasonal changes in this picturesque region, explore the detailed insights at Locarno Climate.