September Weather in , Slovenia

Last updated: August 27, 2025

September in Slovenia offers a dynamic weather experience, with temperatures ranging from a maximum of 29°C (85°F) to a refreshing 1°C (33°F) at night. The average temperature settles at a comfortable 15°C (60°F), making it an inviting month for outdoor activities. However, prepare for occasional rain, as the region experiences 139 mm (5.5 in) of precipitation over 13 days, contributing to a humidity level of 74%. This blend of warmth and moisture creates a lush and vibrant landscape, perfect for exploring Slovenia's natural beauty.

September Temperature in

As September rolls into Slovenia, the landscape begins to transition from the warmth of summer to the cooler embrace of autumn. With temperatures ranging from a brisk 1°C (33°F) at night to a comfortable 29°C (85°F) during the day, the month offers a delightful balance of warmth and coolness. The average temperature settles at 15°C (60°F), allowing for pleasant outdoor activities amidst the stunning fall foliage. This gradual drop in temperature marks a shift from the high summer peaks seen in August, where maximums reached 35°C (96°F). As the days shorten and the air crispens, September serves as a picturesque prelude to the enchanting colors and cooler winds of the coming months.

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

The chart illustrates September temperature patterns in , showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In , 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).
JanFebMarAprMayJunJulAugSepOctNovDec323742505767696960514234
Data source: Temperature data for 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

September marks a notable increase in precipitation in Slovenia, with an impressive 139 mm (5.5 in) of rain recorded over 13 days. This uptick follows a summer of relatively high rainfall, particularly in July and August, which saw 121 mm (4.8 in) and 114 mm (4.5 in) respectively. The transition into autumn brings not only more rainfall but also a shift in the overall weather pattern, as September's precipitation levels surpass those of the preceding months, such as April and May. This trend indicates a clear seasonal shift, with September often serving as a bridge to the wetter, cooler months ahead, setting the stage for a lush landscape as nature prepares for winter.

September Precipitation Trends in

The chart displays monthly precipitation patterns in , 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 , September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec417263931529012111413980118100
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in

September in Slovenia experiences a noticeable shift in humidity, settling at a comfortable 74%. This marks a slight increase from the summer months, where August dipped to 68%, reflecting the gradual transition into the cooler fall season. As temperatures begin to drop, the humidity levels slightly rise again, preparing for the higher moisture content typical of autumn. Compared to earlier months, the trend shows a decline from the 91% humidity of January to September's more moderate levels, indicating a gradual easing of the summer swelter. The overall pattern signals a shift towards a more refreshing atmosphere, perfect for enjoying Slovenia's picturesque landscapes as the leaves start to change.

September Average Humidity in

This chart illustrates the average monthly humidity levels in , 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 is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec91%87%82%79%74%75%74%69%74%88%90%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in

As September arrives in Slovenia, the UV Index drops to 6—still classified as high, which means care is needed when enjoying outdoor activities. Following the intense very high levels of UV radiation experienced in the summer months, where the UV Index peaked at 9, September offers a slight reprieve with an extended burn time of 25 minutes. This trend reflects a gradual shift towards milder conditions as the year progresses, with the UV Index expected to fall further in October. Regardless, it's important to stay informed and protect your skin this month. For more details on UV levels throughout the year, visit UV Index.

Maximum UV Index Levels in for September

The chart shows the monthly maximum UV Index (UVI) for 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 typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235689986432
Data source: 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

As summer edges into autumn, September in Slovenia still enjoys a delightful 306 hours of sunshine, albeit a noticeable decline from the sun-drenched heights of July and August. This month marks the transition from the peak of summer with its 414 hours in July, gradually tapering off as the days grow shorter. With the bright rays of May and June leading the charge, September retains a remarkable amount of sun, making it an ideal time for outdoor activities amid the picturesque autumn scenery. While daylight diminishes into the cozy embrace of October's 272 hours, September still shines as a bridge between the vibrant summer days and the crisp fall ambiance, inviting visitors to bask in its warm glow before winter approaches.

Monthly Sunshine Duration in : September Highlighted

The September sunshine duration represents the total number of hours 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.
JanFebMarAprMayJunJulAugSepOctNovDec170h210h299h329h352h393h414h380h306h272h187h199h
Data source: September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in During September

As summer transitions into autumn, September in Slovenia offers a 49% chance of sunny weather, making it one of the more promising months for sunshine. While it may not reach the peak levels found in the spring and early summer, where chances hover around 55% in March and dip to 33% in May, September provides a satisfying balance. Visitors can still expect relatively clear skies and pleasant days, especially in contrast to the gloomier months ahead, such as November at just 23%. This month is perfect for those who relish outdoor activities bathed in mellow sunshine before the chill of autumn truly sets in.

Percentage of Sunny Days in September in

The chart illustrates the percentage of sunny days in 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 experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec26%42%55%35%33%51%46%42%49%34%23%32%
Data source: September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in in September

As summer gives way to autumn in Slovenia, September brings a gentle transition in daylight duration, offering around 12 hours of natural light each day. This marks a noticeable decrease from the sun-drenched days of July and August, which boast up to 15 hours of daylight. The gradual shift from the long days of summer highlights the progression toward shorter daylight hours, a trend that continues into October with only 10 hours remaining. Although September's daylight is less than the enchanting summer months, it still captures the beauty of early fall, where the vibrant landscapes start to transform in preparation for the quieter months ahead.

Average Daylight Hours in for September

The chart illustrates the variation in daylight duration in throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 3m10h 19m11h 56m13h 35m14h 59m15h 42m15h 20m14h 4m12h 29m10h 51m9h 24m8h 39m
Data source: daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in

In September, Slovenia experiences a gentle caress of wind with an average speed of 1.5 m/s (3 mph), continuing the trend of calm conditions typical for the late summer month. The subtle shift from the warmer August breezes, which average slightly lower at 1.4 m/s, signals the impending transition into autumn. This mild wind, often intertwined with the crispness of the approaching season, creates a refreshing atmosphere perfect for outdoor activities. As the year progresses into October, the winds pick up slightly to 1.7 m/s, hinting at the cooler days ahead while maintaining the overall tranquil climate that characterizes Slovenia throughout much of the year.

Average September Wind Speed in

The chart displays monthly wind speed patterns in , 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.
JanFebMarAprMayJunJulAugSepOctNovDec1.61.91.71.91.81.61.71.41.5 m/s1.71.51.5
Data source: September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Compares to Other Months

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

September and January present a stark contrast in weather conditions. In September, temperatures can soar to a pleasant maximum of 29°C (85°F), with an average of 15°C (60°F) and a minimum of 1°C (33°F). This month also experiences significant rainfall, totaling 139 mm (5.5 in) over approximately 13 days, along with a moderate humidity level of 74%. In comparison, January is much colder, with temperatures typically ranging from a minimum of -16°C (3°F) to a maximum of only 12°C (54°F), averaging around 0°C (32°F). This winter month sees much less precipitation, totaling just 41 mm (1.6 in) over about 6 days, but it has a notably higher humidity level of 91%. For more details about the weather in January, visit weather in January.

September and February showcase stark contrasts in weather patterns. In September, temperatures range from a chilly 1°C (33°F) at night to a warm 29°C (85°F) during the day, with an average of 15°C (60°F). This month experiences significant rainfall, with 139 mm (5.5 in) over approximately 13 days, along with a humidity level of 74%. In contrast, February presents a much colder climate, where temperatures can plummet to a minimum of -14°C (7°F) and reach a maximum of 19°C (66°F), averaging around 3°C (37°F). Precipitation is less frequent, totaling 72 mm (2.8 in) across about 8 days, but the humidity is notably higher at 87%. For more detailed insights, check the weather in February.

September and March exhibit contrasting weather patterns that reflect the transition between summer and winter. In September, temperatures range from a mild 1°C (33°F) to a warm 29°C (85°F), with an average of 15°C (60°F), along with relatively high humidity at 74%. This month also experiences more precipitation, totaling 139 mm (5.5 in) over roughly 13 days. In stark contrast, March sees much cooler temperatures, with a minimum of -15°C (5°F) and a maximum of 21°C (71°F), averaging just 5°C (42°F). Additionally, March has lower precipitation at 63 mm (2.5 in) over 10 days, accompanied by higher humidity at 82%. For more detailed information, you can check the weather in March.

September and April showcase distinct weather patterns that highlight the transition between seasons. In September, temperatures range from a chilly 1°C (33°F) at night to a warm 29°C (85°F) during the day, with an average of 15°C (60°F). The month is relatively humid at 74%, with about 139 mm (5.5 in) of precipitation spread over 13 days. In contrast, April experiences cooler temperatures with a minimum of -9°C (16°F) and a maximum of 25°C (78°F), averaging 10°C (50°F). While April has slightly lower precipitation at 93 mm (3.7 in) over 12 days, it is slightly more humid with 79%. For a detailed look at the weather in April, visit weather in April.

When comparing the weather in September and May, both months showcase a range of temperatures and similar humidity levels. September typically experiences a minimum temperature of 1°C (33°F) and averages around 15°C (60°F), peaking at a maximum of 29°C (85°F). In contrast, May starts slightly cooler, with a minimum of 0°C (32°F) and an average of 14°C (57°F), while reaching a maximum of 28°C (82°F).

Precipitation is slightly higher in May at 152 mm (6.0 in) over 19 days, compared to September’s 139 mm (5.5 in) over 13 days. However, both months maintain a humidity level of 74%, contributing to a similar atmosphere. For more detailed information, be sure to check out the weather in May.

In June, the weather typically ranges from a minimum temperature of 5°C (41°F) to a maximum of 34°C (93°F), with an average of 19°C (67°F). The month experiences about 90 mm (3.5 in) of precipitation over approximately 15 days, and humidity levels hover around 75%. In contrast, September sees a wider temperature range, with minimums dipping to 1°C (33°F) and maximums reaching up to 29°C (85°F), averaging at 15°C (60°F). Precipitation is higher in September at 139 mm (5.5 in) over 13 rainy days, while humidity remains fairly consistent at 74%. For more details on the weather specific to June, you can refer to weather in June.

In comparing the weather between September and July, we notice distinct differences in temperature and precipitation patterns. September experiences cooler temperatures, with a minimum of 1°C (33°F) and an average of 15°C (60°F), while July is warmer with a minimum of 10°C (50°F) and an average of 20°C (69°F). The maximum temperature in September reaches 29°C (85°F), compared to July's higher maximum of 32°C (91°F). Additionally, September sees slightly more precipitation totaling 139 mm (5.5 in) over 13 days, while July has 121 mm (4.8 in) over 15 days. Despite these differences, both months share the same humidity level of 74%. For more detailed insights, check out the weather in July.

In comparing the weather patterns of September and August, notable differences emerge. September experiences a broader temperature range with minimums dropping to 1°C (33°F) and maximums reaching 29°C (85°F), compared to August's milder minimum of 8°C (46°F) and maximum of 35°C (96°F). While August boasts a warmer average temperature of 21°C (69°F), September's average settles at 15°C (60°F). Precipitation is slightly higher in September, measuring 139 mm (5.5 in) over 13 days, whereas August sees 114 mm (4.5 in) across 14 days. Additionally, September's humidity level is at 74%, surpassing the 68% humidity in August. For a detailed overview of August's conditions, you can visit weather in August.

September and October exhibit a notable shift in weather patterns. In September, temperatures range from a minimum of 1°C (33°F) to a maximum of 29°C (85°F), with an average of 15°C (60°F). The month sees considerable precipitation, totaling 139 mm (5.5 in) over 13 days, with humidity at a moderate 74%. In contrast, October brings cooler temperatures, with a minimum of -1°C (31°F) and a maximum of 23°C (74°F), averaging around 11°C (51°F). Precipitation decreases to 80 mm (3.2 in), occurring over 9 days, while humidity rises to 88%. For more detailed information about the weather in October, please follow the link.

September and November offer contrasting weather experiences. In September, temperatures can range from a cool 1°C (33°F) at night to a warm 29°C (85°F) during the day, with an average temperature of 15°C (60°F). The month is characterized by relatively high humidity at 74% and sees around 139 mm (5.5 in) of precipitation over 13 days. In contrast, November brings a much colder atmosphere, with temperatures dropping to a minimum of -8°C (17°F) and an average of just 6°C (43°F). While it has slightly less precipitation at 118 mm (4.6 in) over 10 days, humidity increases to 90%. For more details, you can check the weather in November.

September and December present a stark contrast in weather patterns. In September, temperatures range from a minimum of 1°C (33°F) to a maximum of 29°C (85°F), with an average of 15°C (60°F), making it a relatively warm month. The rainfall is significant, totaling 139 mm (5.5 in) over 13 days, with humidity levels at 74%. In contrast, December experiences much colder temperatures, with a minimum of -17°C (1°F) and a maximum of 14°C (57°F), averaging just 1°C (34°F). Although December sees less precipitation at 100 mm (3.9 in) across 10 days, it has a higher humidity level of 89%, contributing to a chilly and damp atmosphere. For more detailed information, check out the weather in December.

Compare 's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in

As September arrives, the weather begins to transition, offering a unique blend of warmth and coolness that distinguishes it from the hotter summer months. With a maximum temperature that still flirts with the warmth of 29°C (85°F), the days can feel pleasantly warm; however, average lows of 1°C (33°F) signal the onset of crisp autumn nights. This month sees a notable increase in precipitation, with 13 days of rain and a total of 139 mm (5.5 in), creating a vibrant atmosphere as nature prepares for the cooler months ahead. The humidity at 74% adds a touch of heaviness to the air, but it also enriches the landscape, as the colors of foliage begin to shift. For a comprehensive understanding of how September fits into the broader climate patterns, explore more at Climate.