September Weather in Celje, Slovenia

Last updated: August 27, 2025

In September, Celje, Slovenia experiences a delightful transition into autumn, with maximum temperatures reaching 30°C (87°F) and an average of 16°C (61°F). Nights can be crisp, dipping to a minimum of 2°C (36°F). The month brings 127 mm (5.0 in) of precipitation over approximately 12 days, contributing to the lush landscapes typical of this stunning region. With an average humidity of 65%, September offers a refreshing atmosphere, making it a perfect time for outdoor activities and exploration amidst the picturesque scenery of Celje.

September Temperature in Celje

As September rolls into Celje, Slovenia, the temperature begins to show a delightful transition from the summer heat to the cooler embrace of autumn. With minimums around 2°C (36°F) and maximums peaking at a comfortable 30°C (87°F), this month strikes an appealing balance of warmth and crispness. The average temperature of 16°C (61°F) invites locals and visitors alike to relish outdoor activities, while also hinting at the seasonal change with cooler evenings. As the days shorten and the leaves start to turn, September is a perfect time to enjoy the lingering warmth before the chill of October sets in.

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

The chart illustrates September temperature patterns in Celje, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Celje, 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).
JanFebMarAprMayJunJulAugSepOctNovDec333843515868707061524335
Data source: Temperature data for Celje 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 Celje

In September, Celje, Slovenia, experiences a noteworthy burst of rainfall, with precipitation reaching 127 mm (5.0 in) over 12 days. This marks the peak of the summer's transition into autumn, showcasing a significant increase compared to the preceding months, such as August's 104 mm and July's 121 mm. The frequency of rainy days also reflects this shift, as September maintains a moderate count, balancing occasional downpours with glimpses of early fall sunshine. This combination of increased rainfall and measurable rain days hints at a gradual return to cooler temperatures, setting the stage for the wetter autumn months ahead.

September Precipitation Trends in Celje

The chart displays monthly precipitation patterns in Celje, 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 Celje, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec3764578014282121104127719886
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Celje

In Celje, Slovenia, September marks a transitional month for humidity, as the summer heat begins to wane. With an average humidity of 65%, September showcases a noticeable decline from the sweltering 60% in August, while still remaining relatively moderate compared to the wetter months ahead. This gradual decrease highlights the shift in seasons, with humidity noticeably higher in the colder months, reaching a peak of 90% in January. Overall, the trend from summer to fall reflects a comfortable environment, setting the stage for the crisp autumn air that follows.

September Average Humidity in Celje

This chart illustrates the average monthly humidity levels in Celje, 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 Celje is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%84%78%73%71%73%70%60%65%84%89%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Celje

As September unfolds in Celje, Slovenia, the UV Index stands at 6, placing it in the high exposure category and allowing for a burn time of 25 minutes. This signals a noticeable drop from the summer peaks of 9 in July and August, reflecting the transition into autumn. With the UV Index decreasing, residents and visitors can enjoy the outdoors with a reduced risk of sunburn, yet it remains essential to stay protected during peak sunlight. As October approaches, the UV levels will continue to dip, shifting towards a more moderate exposure category. For more detailed information about UV levels throughout the year, visit Celje UV Index.

Maximum UV Index Levels in Celje for September

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

As summer gracefully transitions into autumn, September in Celje, Slovenia, shines with an impressive 311 hours of sunlight. This month reveals a beautiful ebb in daylight compared to the sun-drenched heights of July, which boasts over 418 hours, yet it still surpasses the early months of the year. After the vibrant blooms of May and June, which enjoy peak sunshine, September maintains a warm glow, making it a delightful time for outdoor activities. As the days grow shorter, the balance of daylight becomes a gentle reminder of the changing seasons, yet September remains a cherished month for enjoying the fading warmth of summer.

Monthly Sunshine Duration in Celje: September Highlighted

The September sunshine duration represents the total number of hours Celje 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.
JanFebMarAprMayJunJulAugSepOctNovDec165h212h298h332h358h396h418h385h311h279h191h201h
Data source: Celje September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Celje During September

In September, Celje, Slovenia enjoys a favorable 51% chance of sunny weather, making it one of the most promising months for sunshine throughout the year. This figure reflects a slight uptick from the summer months, such as July and August, which feature chances of 48% and 43%, respectively. Interestingly, September stands out as a transitional month, bridging the warmth of summer and the crispness of autumn. As the season shifts, the likelihood of sunshine remains relatively high compared to April and October, both of which drop to 36% and 37%. Overall, September is an excellent time to bask in the sun’s rays while enjoying the beautiful landscapes of Celje.

Percentage of Sunny Days in September in Celje

The chart illustrates the percentage of sunny days in Celje 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 Celje experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec27%46%56%36%36%52%48%43%51%37%25%33%
Data source: Celje September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Celje in September

In Celje, Slovenia, September marks a gentle transition as daylight begins to wane, offering about 12 hours of sunlight. This month reflects a gradual shift from the peak summer brightness of 15 hours in June and July, through the 14 hours of August, to a noticeable decrease in the following months. As the days shorten, it emphasizes the change of seasons, with October dropping to 10 hours. This rhythmic fluctuation highlights the annual cycle, inviting residents and visitors alike to savor the lingering warmth of late summer before autumn's embrace takes hold.

Average Daylight Hours in Celje for September

The chart illustrates the variation in daylight duration in Celje 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 20m11h 56m13h 35m14h 59m15h 42m15h 19m14h 4m12h 29m10h 51m9h 24m8h 39m
Data source: Celje daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Celje

As September arrives in Celje, Slovenia, the gentle whispers of the wind continue the summer’s trend, with an average speed of 1.6 m/s (4 mph). This marks a slight dip compared to the preceding months, reflecting the transition from the warm summer breezes towards the cooler onset of autumn. The wind's calming presence carries hints of the changing seasons, as it has generally stayed low throughout the summer, peaking in the spring months. Overall, this decrease in wind speed suggests a serene environment, ideal for enjoying the vibrant autumn colors that begin to paint the landscape.

Average September Wind Speed in Celje

The chart displays monthly wind speed patterns in Celje, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.02.21.92.12.01.81.91.61.6 m/s2.01.51.7
Data source: Celje September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Celje Compares to Other Months

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

September and January offer stark contrasts in weather conditions. In September, temperatures typically range from a minimum of 2°C (36°F) to a maximum of 30°C (87°F), with an average of 16°C (61°F). This month sees a moderate amount of rainfall, averaging 127 mm (5.0 in) over about 12 days, accompanied by a humidity level of 65%. In contrast, January experiences much colder temperatures, with a minimum of -17°C (2°F) and a maximum of 12°C (55°F), resulting in a freezing average of 0°C (33°F). Precipitation is considerably lower, averaging 37 mm (1.5 in) over just 6 days, but the humidity is notably higher at 90%. For more detailed information, you can check Celje weather in January.

September and February exhibit striking differences in weather patterns. In September, temperatures range from a mild 2°C (36°F) at night to a warm 30°C (87°F) during the day, with an average of 16°C (61°F). The month experiences considerable rainfall, accumulating 127 mm (5.0 in) over 12 days, contributing to a humidity level of 65%. In contrast, February presents a stark chill, with temperatures dipping as low as -15°C (6°F) at night and reaching a maximum of 20°C (67°F), averaging just 3°C (38°F). Precipitation in February is lighter, with 64 mm (2.5 in) falling over 9 days, but the humidity rises to a notable 84%. For more detailed information, you can check Celje weather in February.

September and March showcase stark contrasts in weather. In September, temperatures range from a mild 2°C (36°F) at night to a warm 30°C (87°F) during the day, with an average of 16°C (61°F). The month experiences significant precipitation, totaling 127 mm (5.0 in) over about 12 days, and a moderate humidity of 65%. In contrast, March is much colder, with temperatures dipping as low as -16°C (4°F) and peaking at 22°C (71°F), averaging around 6°C (43°F). This month sees less precipitation, with 57 mm (2.2 in) spread across 9 days, but the humidity is higher at 78%. For a detailed look at March weather in Celje, visit Celje weather in March.

When comparing the weather in September and April, notable differences in temperature and precipitation emerge. September typically offers milder conditions, with temperatures ranging from a minimum of 2°C (36°F) to a maximum of 30°C (87°F), and an average of 16°C (61°F). In contrast, April experiences cooler temperatures, with a minimum of -8°C (18°F) and a maximum of 26°C (80°F), resulting in an average of only 10°C (51°F). While September sees more rainfall, totaling 127 mm (5.0 in) over 12 days, April features less precipitation at 80 mm (3.2 in) across 11 days. Furthermore, the humidity levels are slightly higher in April (73%) compared to September (65%), giving each month its unique climate characteristics. For more detailed information, you can check Celje weather in April.

When comparing the weather in September and May, we see a few notable differences. September generally has warmer temperatures, with an average of 16°C (61°F) compared to May's average of 15°C (58°F). However, September can experience higher maximum temperatures, reaching up to 30°C (87°F), while May peaks at 29°C (85°F). Both months are relatively wet, but September has slightly less precipitation at 127 mm (5.0 in) over 12 days compared to May, which sees 142 mm (5.6 in) over 19 days. Additionally, humidity levels in May are a bit higher at 71%, compared to 65% in September. For more detailed information on the weather in May, you can check Celje weather in May.

When comparing the weather in September and June, notable differences emerge in temperature and humidity. September experiences a broader temperature range, with minimums dipping to 2°C (36°F) and maximums reaching up to 30°C (87°F), while June generally has milder temperatures, with minimums of 6°C (43°F) and maximums hitting 34°C (94°F). Additionally, June tends to be slightly more humid at 73%, compared to September's 65%. Precipitation is also higher in September, with 127 mm (5.0 in) of rain across 12 days, compared to June's 82 mm (3.2 in) over 13 days. For more details on June weather, you can check Celje weather in June.

When comparing the weather in September to that of July, September experiences a wider temperature range with minimums dropping to 2°C (36°F) and maximums reaching up to 30°C (87°F), contrasted with July, which has a milder minimum of 10°C (50°F) and a peak of 33°C (92°F). While September's average temperature is cooler at 16°C (61°F) compared to July's warmer average of 21°C (70°F), both months see significant rainfall, with September receiving 127 mm (5.0 in) over 12 days, and July slightly less with 121 mm (4.8 in) across 15 days. Humidity levels are also higher in July at 70%, compared to September's 65%. For more details on July's weather, refer to Celje weather in July.

September weather shows a notable shift compared to August, with average temperatures dropping from 21°C (70°F) in August to 16°C (61°F) in September. The maximum temperature in September reaches 30°C (87°F), which is lower than August's peak of 36°C (96°F). Additionally, September experiences slightly higher precipitation at 127 mm (5.0 in) over 12 days, compared to August's 104 mm (4.1 in) over 13 days. Humidity also increases slightly in September, averaging 65% compared to 60% in August. For more details on August weather patterns, visit Celje weather in August.

In September, temperatures range from a minimum of 2°C (36°F) to a maximum of 30°C (87°F), with an average of 16°C (61°F). The month experiences significant rainfall, accumulating 127 mm (5.0 in) over 12 days, while humidity stands at 65%. Conversely, October brings cooler weather with temperatures dropping to a minimum of -1°C (31°F) and an average of 11°C (52°F), peaking at 24°C (75°F). Rainfall decreases to 71 mm (2.8 in) over 8 days, and humidity rises to 84%. For more detailed insights, check out Celje weather in October.

September and November present contrasting weather patterns, reflecting the transition from summer to autumn. In September, temperatures range from a mild minimum of 2°C (36°F) to a warm maximum of 30°C (87°F), with an average temperature of 16°C (61°F). The month experiences a relatively high level of precipitation totaling 127 mm (5.0 in) over 12 days and a humidity of 65%.

In contrast, November sees a drop in temperatures, with minimums reaching as low as -6°C (22°F) and averages settling at 6°C (43°F). While the maximum temperature still reaches a pleasant 20°C (69°F), the month is characterized by cooler temperatures, higher humidity at 89%, and less precipitation at 98 mm (3.9 in) over 11 days. For more specific details on November weather in Celje, check out Celje weather in November.

In September, the weather is characterized by a significant range in temperature, with minimums around 2°C (36°F) and maximums reaching up to 30°C (87°F), leading to an average of 16°C (61°F). The month sees considerable precipitation of 127 mm (5.0 in) over approximately 12 days, with a moderate humidity level of 65%. In contrast, December's climate presents a stark shift, as temperatures drop dramatically, with minimums plummeting to -15°C (5°F) and maximums capping at 15°C (60°F), giving an average temperature of just 2°C (35°F). Although December experiences less precipitation, totaling 86 mm (3.4 in) over 9 days, it brings higher humidity at 89%. For more details, you can view the Celje weather in December.

Compare Celje's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Celje

As summer transitions into autumn, September in Celje brings a delightful mix of warmth and cooling breezes. With average temperatures settling around a comfortable 16°C, the days can still sizzle with peaks reaching 30°C, making it far warmer than the chilly winter months. However, these sunny days intermingle with an increase in rainfall, boasting around 127 mm over 12 days, which adds a refreshing touch to the air. The humidity levels at 65% contribute to a pleasant, crisp feel that distinguishes September from both the sweltering heights of August and the cool embrace of October. For a deeper dive into the evolving Celje climate, explore Celje Climate.