September Weather in Bratislava, Slovakia

Last updated: August 31, 2025

September in Bratislava, Slovakia showcases a delightful transition from summer to autumn, with temperatures ranging from a maximum of 32°C (89°F) to a refreshing minimum of 2°C (35°F). The average temperature lingers around 17°C (63°F), making it a pleasant month for outdoor activities. However, visitors should be prepared for occasional rain, as the city experiences approximately 85 mm (3.4 in) of precipitation over 10 days, accompanied by a notable humidity level of 75%. Whether you’re exploring historic sites or enjoying local cuisine, September offers a captivating blend of warm days and cool evenings in the heart of Slovakia.

September Temperature in Bratislava

In September, Bratislava basks in a comfortable warmth, transitioning gracefully from summer’s heat to the cooler embrace of autumn. With minimum temperatures around 2°C (35°F) and delightful averages reaching 17°C (63°F), locals and visitors alike enjoy a pleasant climate that invites outdoor exploration. The warmth peaks at a maximum of 32°C (89°F), reminiscent of summer's lingering presence, but as the month progresses, the crispness of fall begins to emerge. This month serves as a bridge, offering a perfect blend of sunny days and refreshing evenings, setting the stage for a vibrant autumn in Slovakia's capital.

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

The chart illustrates September temperature patterns in Bratislava, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Bratislava, 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).
JanFebMarAprMayJunJulAugSepOctNovDec333843526070727262534437
Data source: Temperature data for Bratislava 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 Bratislava

September marks a notable increase in precipitation for Bratislava, Slovakia, as the city experiences an average of 85 mm (3.4 in) of rain over 10 days. This spike follows the summer months, which saw relatively lower rainfall amounts, with August recording 72 mm (2.8 in). The transition into autumn signals a shift in weather patterns, with September's contributions pushing the monthly totals higher and hinting at the wetter conditions to come in the fall. This pattern not only enhances the lushness of the surrounding landscapes but also suggests that locals should prepare for more frequent rain as they embrace the changing season. Overall, September stands out as a month where the balance between warm days and increased precipitation creates a unique atmosphere in the capital.

September Precipitation Trends in Bratislava

The chart displays monthly precipitation patterns in Bratislava, 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 Bratislava, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec353234357764657285494959
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Bratislava

In September, Bratislava experiences a noticeable shift in humidity, with levels around 75%. This marks a gradual decline from the higher humidity typical of the summer months, reflecting the transition into autumn. As the warmth of July and August gives way to cooler temperatures, the city's atmosphere becomes more comfortable, inviting residents and visitors to enjoy the vibrant fall season. Despite this drop, the humidity remains higher than in the spring, where April's average stands at 78%. Thus, September offers a pleasant balance, bridging the lingering warmth of summer with the refreshing chill of the incoming months.

September Average Humidity in Bratislava

This chart illustrates the average monthly humidity levels in Bratislava, 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 Bratislava is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%87%85%78%74%77%76%76%75%85%90%91%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Bratislava

In September, Bratislava experiences a UV Index of 6, categorized as high, which suggests that sun exposure can be more intense, particularly during midday hours. As autumn begins to settle in, residents and visitors alike should remain vigilant, as the burn time is estimated at 25 minutes—a sharp contrast to the very high UV indices seen during the peak summer months. This month marks a gradual decline from August's high index of 7, reflecting the season's transition. With this changing UV intensity, it's crucial to stay protected from harmful rays by using sunscreen and wearing appropriate clothing. For more information on UV conditions in Bratislava, visit the Bratislava UV Index.

Maximum UV Index Levels in Bratislava for September

The chart shows the monthly maximum UV Index (UVI) for Bratislava 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 Bratislava typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235688876421
Data source: Bratislava 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 Bratislava

September in Bratislava welcomes an impressive 320 hours of sunshine, marking a significant shift from the sun-drenched days of summer. Following the peak warmth of July and August, which boast 430 and 389 hours respectively, September offers a delightful blend of sunny spells and cooler breezes as autumn approaches. This month shines brighter than the preceding months, showcasing a steady decline in daylight towards the winter but still managing to eclipse the gloom of November and December. As temperatures settle, the warm rays of early autumn provide the perfect backdrop for outdoor exploration and leisurely strolls, inviting both locals and visitors to soak in the captivating hues of the season.

Monthly Sunshine Duration in Bratislava: September Highlighted

The September sunshine duration represents the total number of hours Bratislava 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.
JanFebMarAprMayJunJulAugSepOctNovDec151h222h301h340h382h417h430h389h320h274h192h174h
Data source: Bratislava September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Bratislava During September

In Bratislava, Slovakia, September offers a delightful balance of sun and shade, boasting a 51% chance of sunny weather. This puts the month comfortably in the middle of the spectrum, slightly higher than August's 41% and quite similar to October's 52%. The trend leading into September indicates a gradual increase in sunlight after the summer months, particularly marked by a peak in June at 57%. As summer transitions into autumn, September emerges as an enticing time to visit, with the likelihood of pleasant sunshine, making it an ideal month for outdoor activities and exploration.

Percentage of Sunny Days in September in Bratislava

The chart illustrates the percentage of sunny days in Bratislava 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 Bratislava experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec26%38%56%39%37%57%50%41%51%52%30%23%
Data source: Bratislava September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Bratislava in September

As the summer months fade into autumn, September marks a gentle transition in daylight duration for Bratislava, Slovakia. With a total of 12 hours of daylight, this month sees a gradual decrease from the longer, sun-drenched days of July and August, which average around 15 hours. While September's daylight starts to wane, it still offers a warm embrace of light compared to the shorter winter days ahead. This shift sets the stage for a cozy atmosphere as the city prepares to welcome the crispness of fall, inviting locals and visitors alike to relish the vibrant colors and cool breezes that accompany the changing seasons.

Average Daylight Hours in Bratislava for September

The chart illustrates the variation in daylight duration in Bratislava throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 49m10h 12m11h 55m13h 41m15h 13m15h 59m15h 35m14h 13m12h 31m10h 46m9h 12m8h 23m
Data source: Bratislava daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Bratislava

As summer gracefully gives way to autumn in Bratislava, September ushers in a shift in wind patterns, with an average speed of 2.6 m/s (6 mph). This marks a subtle decline from the more breezy months of May and April, where winds peaked at around 4.0 m/s (9 mph) and 3.8 m/s (8 mph), respectively. The cooling air brings a calmness that complements the vibrant colors of the changing foliage, making it a perfect time for leisurely strolls along the Danube. As the city transitions into October, wind speeds are expected to recover slightly to 3.5 m/s (8 mph), but September remains a gentle reminder of summer's end, offering a serene backdrop for enjoying Bratislava's charm.

Average September Wind Speed in Bratislava

The chart displays monthly wind speed patterns in Bratislava, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3.13.23.23.84.02.93.22.72.6 m/s3.53.33.5
Data source: Bratislava September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Bratislava Compares to Other Months

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

September in Bratislava offers a warm transition into autumn, with temperatures ranging from a mild 2°C (35°F) at night to a toasty average of 17°C (63°F) during the day, peaking at 32°C (89°F). This month experiences about 85 mm (3.4 in) of precipitation over approximately 10 days, and humidity levels are around 75%, providing a pleasant, yet somewhat humid atmosphere.

In stark contrast, January brings the chill of winter, with temperatures dipping as low as -13°C (10°F) and averaging only 1°C (34°F), reaching a maximum of 15°C (60°F). This month sees less precipitation, totaling 35 mm (1.4 in) over about 9 days, but the humidity is higher at 90%, contributing to a persistent cold feel. For more details, you can check Bratislava weather in January.

When comparing the weather in September and February, we see a stark contrast. September typically experiences milder temperatures, with an average of 17°C (63°F) and a warm maximum reaching up to 32°C (89°F), along with a higher precipitation level of 85 mm (3.4 in) over about 10 days. In contrast, February is much colder, with an average temperature of just 3°C (38°F) and nighttime lows that can drop to -11°C (12°F). The precipitation in February is lower, totaling 32 mm (1.3 in) over 8 days, but humidity levels are slightly higher at 87%. For more details on the specifics of February weather, you can check out Bratislava weather in February.

When comparing the weather in September and March, a striking contrast emerges. September features a more moderate temperature range, with minimums around 2°C (35°F) and maximums peaking at 32°C (89°F), making it generally warmer with an average of 17°C (63°F). In contrast, March is much cooler, with minimum temperatures dropping to -12°C (10°F) and an average of just 6°C (43°F), peaking at a maximum of 22°C (72°F). Additionally, September experiences higher precipitation levels at 85 mm (3.4 in) over approximately 10 days, while March has significantly less rain, totaling 34 mm (1.3 in) over 8 days. The humidity in March is slightly higher at 85%, compared to September's 75%. For more detailed insights, you can check Bratislava weather in March.

When comparing the weather in September and April, notable differences emerge. September tends to be warmer, with average temperatures around 17°C (63°F) and maximums reaching up to 32°C (89°F), while April has a cooler average of 11°C (52°F) and a maximum of 29°C (84°F). Despite its warmer weather, September experiences more rainfall, with 85 mm (3.4 in) of precipitation over approximately 10 days, compared to April's 35 mm (1.4 in) over just 7 days. Additionally, humidity levels are similar, with September at 75% and April slightly higher at 78%. For more detailed information, you can check out Bratislava weather in April.

September and May present a striking contrast in weather, despite having similar minimum and maximum temperatures hovering around 2°C (35°F) and 32°C (90°F), respectively. In September, the average temperature is slightly warmer at 17°C (63°F), while May has a cooler average of 16°C (60°F). Precipitation levels in September are a bit higher, with 85 mm (3.4 in) over approximately 10 days, compared to May's 77 mm (3.0 in) across 13 days. Both months experience high humidity, with September sitting at 75% and May at 73%. For a detailed look at the weather conditions during May, check out Bratislava weather in May.

In comparing the weather between September and June, September tends to showcase a wider temperature range, with minimums dropping to 2°C (35°F) and maximums reaching up to 32°C (89°F), averaging 17°C (63°F). In contrast, June experiences warmer temperatures, with minimums at 8°C (47°F) and maximums peaking at 34°C (93°F), averaging a more comfortable 21°C (71°F). While both months see about 10 days of precipitation, September has a higher rainfall total of 85 mm (3.4 in) compared to June's 64 mm (2.5 in). Humidity levels are similar, slightly higher in June at 77% compared to 75% in September. For a more in-depth look at weather specifics, visit Bratislava weather in June.

In comparing the weather between September and July, September experiences a wider temperature range, with minimums dipping to 2°C (35°F) and maximums reaching up to 32°C (89°F), while July maintains warmer temperatures, with minimums around 8°C (47°F) and maximums peaking at 37°C (98°F). Although July is generally hotter, September's average temperature of 17°C (63°F) reflects a noticeable coolness as the season transitions. Additionally, while both months see significant precipitation, September has a higher total of 85 mm (3.4 in) over 10 days, compared to July's 65 mm (2.5 in) over 11 days. Humidity levels remain quite similar, hovering around 75% in September and 76% in July. For more detailed information on July weather, visit Bratislava weather in July.

In September, temperatures range much lower than in August, with nightly lows dropping to around 2°C (35°F) compared to August's milder minimum of 10°C (51°F). While the average temperature in September is a comfortable 17°C (63°F), it still falls short of August's warmer average of 22°C (72°F). Additionally, September experiences a maximum temperature of 32°C (89°F), which is significantly lower than August's peak of 37°C (99°F). Rainfall is slightly higher in September, with 85 mm (3.4 in) over 10 days, compared to 72 mm (2.8 in) during the same number of days in August. Humidity levels are similar in both months, hovering around 75% in September and 76% in August. For more detailed information on the weather, check out Bratislava weather in August.

September and October exhibit a notable transition in weather conditions. In September, temperatures range from a minimum of 2°C (35°F) to a maximum of 32°C (89°F), with an average of 17°C (63°F). This month sees a total precipitation of 85 mm over approximately 10 days, coupled with a humidity level of 75%. In contrast, October brings cooler temperatures, with a minimum of -2°C (29°F), an average of 12°C (54°F), and a maximum of 25°C (77°F). Precipitation decreases to 49 mm over 8 days, and humidity rises slightly to 85%. For more details on weather patterns, you can check Bratislava weather in October.

September typically enjoys warmer temperatures with averages around 17°C (63°F) and highs reaching up to 32°C (89°F), making it a more comfortable month for outdoor activities. However, November brings a noticeable drop in temperature, with averages settling around 7°C (44°F) and highs peaking at 19°C (66°F). While September has a higher average humidity of 75% and more precipitation (85 mm over 10 days), November experiences even higher humidity at 90%, but with less overall rain at 49 mm across 9 days. For more detailed insights into November weather, you can explore Bratislava weather in November.

In September, the weather is significantly warmer, with temperatures ranging from a minimum of 2°C (35°F) to a maximum of 32°C (89°F), averaging around 17°C (63°F). This month experiences approximately 85 mm (3.4 in) of precipitation over 10 days and maintains a humidity level of 75%. In contrast, December brings colder temperatures, with a minimum of -7°C (20°F) and a maximum of 13°C (56°F), averaging just 3°C (37°F). Although December has less precipitation at 59 mm (2.3 in) spread over 11 days, the humidity is higher at 91%. For more detailed information, visit Bratislava weather in December.

Compare Bratislava's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Bratislava

As summer transitions into autumn, September in Bratislava offers a unique blend of warm days and cooler nights, making it a delightful time to experience the city. Unlike the peak heat of the summer months, where temperatures soar, September boasts a comfortable average that invites exploration. With occasional rainfall and a noticeable drop in humidity, it provides a refreshing ambiance perfect for outdoor activities and sightseeing. The interplay of warmer afternoons and cooler evenings adds a special charm, urging visitors to enjoy longer days while savoring the crispness of early autumn. For more insights into the city's evolving weather patterns, explore Bratislava Climate.