September Weather in Zagreb, Croatia

Last updated: March 17, 2025

September in Zagreb, Croatia offers a striking blend of warmth and occasional rain, making it a dynamic month for visitors and locals alike. The maximum temperature can reach a sizzling 34°C (93°F), while the average hovers around a pleasant 18°C (64°F), providing ideal conditions for exploring the city’s vibrant culture. However, temperatures can dip down to a cool 3°C (38°F) at night, so layering is advisable. With a total precipitation amount of 98 mm (3.9 in) across about 10 rainy days, the month brings refreshing showers that nourish the lush surroundings. Relative humidity stands at 62%, adding a mild stickiness to the warm afternoons. Whether you’re planning outdoor adventures or cozy indoor activities, September's weather in Zagreb promises to be memorable.

September Temperature in Zagreb

In September, Zagreb experiences a delightful transition from the warm summer months to the crispness of autumn. Temperatures begin to cool down, with minimums averaging around 3°C (38°F) and maximums reaching up to 34°C (93°F), allowing for a pleasant range that invites both outdoor exploration and cozy indoor activities. The average temperature hovers at 18°C (64°F), providing a comfortable backdrop for the city’s vibrant cultural scene, while the increasing likelihood of cooler evenings signals the approach of fall. Those visiting can expect a beautiful blend of warm days and refreshing nights, perfect for enjoying leisurely strolls through the city's picturesque streets and parks.

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

The chart illustrates September temperature patterns in Zagreb, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec344045546271737464544538
Data source: Temperature data for Zagreb 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 Zagreb

September in Zagreb, Croatia, marks the transition into autumn, and the weather reflects this shift with a notable increase in precipitation. With 98 mm (3.9 in) of rain falling over 10 days, the month captures a balance between lingering summer warmth and the onset of cooler, wetter conditions. This uptick in rainfall follows the drier summer months, where August recorded 74 mm (2.9 in), and sets the stage for the wetter months ahead. As the city prepares for October's 84 mm (3.3 in) of rainfall, September serves as a reminder of the seasonal changes, benefiting the lush landscapes that characterize Zagreb.

September Precipitation Trends in Zagreb

The chart displays monthly precipitation patterns in Zagreb, 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.
JanFebMarAprMayJunJulAugSepOctNovDec3966526812096887498849086
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Zagreb

As summer gives way to autumn, September in Zagreb, Croatia, experiences a modest increase in humidity, reaching 62%. This marks a significant rise from the season's low in August, which saw humidity levels plummet to 51%. The transition signals a shift in the atmosphere as the city prepares for the cooler months ahead. Notably, this spike sets the stage for a gradual climb in humidity as October approaches, where levels will climb dramatically to 81%. Overall, September serves as a bridge between the dry warmth of summer and the wetter conditions characteristic of the fall, highlighting the dynamic climate of Zagreb throughout the year.

September Average Humidity in Zagreb

This chart illustrates the average monthly humidity levels in Zagreb, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec89%83%75%72%70%69%64%51%62%81%87%88%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Zagreb

As September unfolds in Zagreb, the UV Index can be expected to sit at a high level of 6, offering a reminder of the sun's strength as summer gives way to autumn. This marks a decline from the very high values of 8 and 9 seen in the peak summer months of June and July, where a mere 15 minutes of unprotected sun exposure could lead to burns. In contrast, the beginning of fall allows for 25 minutes of safe exposure before one must seek shade or protective measures. Overall, while the intensity of UV radiation decreases from the summer peak, September still calls for mindful sun protection as the days remain bright. For more detailed insights into UV levels, visit Zagreb UV Index.

Maximum UV Index Levels in Zagreb for September

The chart shows the monthly maximum UV Index (UVI) for Zagreb 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.
JanFebMarAprMayJunJulAugSepOctNovDec235689986532
Data source: Zagreb 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 Zagreb

As summer gracefully transitions into autumn, Zagreb enjoys a delightful dose of sunshine in September, basking in approximately 326 hours of radiant daylight. This month signals a subtle shift, where warmth lingers from the peak summer months of June and July, which boast over 400 hours of sun, yet a noticeable decline begins as the days shorten. Unlike the vibrant May and June, when the sun is at its zenith, September still encapsulates a warm charm that invites locals and visitors alike to savor the outdoors. With the sun's embrace still felt, this transitional month offers a vibrant blend of lingering summer vibes and the picturesque onset of autumn, making Zagreb a perfect destination for those looking to relish the final rays of summer.

Monthly Sunshine Duration in Zagreb: September Highlighted

The September sunshine duration represents the total number of hours Zagreb 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.
JanFebMarAprMayJunJulAugSepOctNovDec162h226h307h335h371h406h426h391h326h288h191h204h
Data source: Zagreb September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Zagreb During September

As summer fades, the likelihood of sunny weather in Zagreb during September stands at a promising 52%. This places the month comfortably above the averages of the spring and early summer months, marking a slight increase compared to August's steady 50% chance of sunshine. While it doesn’t quite reach the peak predicted in March at 58%, September offers a delightful balance between warmth and clear skies, inviting outdoor activities and exploration. As autumn approaches, the weather remains capricious, but those in Zagreb can still enjoy ample opportunities to bask in the sun before the chill of October sets in.

Percentage of Sunny Days in September in Zagreb

The chart illustrates the percentage of sunny days in Zagreb 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 Zagreb experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec28%48%58%41%39%57%50%50%52%39%21%28%
Data source: Zagreb September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Zagreb in September

As September arrives in Zagreb, Croatia, the city transitions gracefully from the long, sunlit days of summer into the crisp embrace of autumn. With 12 hours of daylight, September offers a perfect balance, allowing residents to enjoy the lingering outdoor warmth while daylight begins to wane. This month marks a gentle decline from the peak daylight of 15 hours seen in June and July, yet remains brighter than the 10 hours that characterize October. As the days shorten, the shift in daylight serves as a reminder of the seasonal change, inviting both locals and visitors to savor the beauty of the city's parks and vibrant streets before the shorter days of fall settle in.

Average Daylight Hours in Zagreb for September

The chart illustrates the variation in daylight duration in Zagreb throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 6m10h 21m11h 56m13h 33m14h 56m15h 38m15h 16m14h 2m12h 29m10h 52m9h 27m8h 43m
Data source: Zagreb daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Zagreb

As September rolls into Zagreb, the city experiences a gentle breeze with an average wind speed of 1.8 m/s (4 mph), slightly higher than the calmer summer months. This subtle increase in wind breathes new life into the atmosphere, making it the perfect backdrop for early autumn strolls through the city’s vibrant streets. Compared to the preceding months, September’s winds are a reminder of the transition from the warm summer days to the refreshing coolness of fall. Observing trends from earlier data, it’s clear that wind speeds tend to pick up slightly in the cooler months, with a gradual rise expected as October approaches, inviting the crisp energy of autumn into Zagreb's enchanting landscapes.

Average September Wind Speed in Zagreb

The chart displays monthly wind speed patterns in Zagreb, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.22.22.32.42.31.92.01.71.8 m/s2.11.81.8
Data source: Zagreb September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Zagreb Compares to Other Months

The weather in Zagreb changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in Zagreb and find detailed weather information for every month.

September and January present starkly contrasting weather patterns. In September, temperatures range from a mild 3°C (38°F) to a sweltering 34°C (93°F), with an average of 18°C (64°F), creating a warm environment that invites outdoor activities. Conversely, January is characterized by much colder temperatures, with a minimum of -12°C (11°F) and an average of 1°C (34°F), peaking at just 16°C (62°F). Additionally, September experiences more precipitation (98 mm or 3.9 in over 10 days) compared to January's 39 mm (1.5 in over 8 days), but January's higher humidity at 89% creates a distinctly chilly atmosphere. For more details on January weather, you can visit Zagreb weather in January.

September and February present starkly contrasting weather conditions. September boasts a wider temperature range, with minimums around 3°C (38°F) and daytime highs reaching up to 34°C (93°F), making it a generally warm month with an average of 18°C (64°F). In contrast, February experiences much colder temperatures, dipping as low as -10°C (14°F) and only reaching a maximum of 21°C (69°F), averaging at 4°C (40°F). Additionally, September sees about 98 mm (3.9 in) of precipitation over 10 days, while February’s precipitation is lower at 66 mm (2.6 in) falling over 9 days. The higher humidity in February at 83% also contributes to the chilliness compared to September's relative humidity of 62%. For more detailed insights, you can visit Zagreb weather in February.

In September, the weather is typically warm, with temperatures ranging from a cool minimum of 3°C (38°F) to a warm maximum of 34°C (93°F), and an average temperature of 18°C (64°F). This month experiences significant rainfall, with about 98 mm (3.9 in) of precipitation over an average of 10 days and a humidity level of 62%. In contrast, March brings much colder conditions, with temperatures ranging from a frigid minimum of -15°C (6°F) to a maximum of 23°C (74°F) and an average of only 7°C (46°F). March also sees less precipitation, totaling 52 mm (2.1 in) over roughly 8 days, and a higher humidity of 75%. For more detailed insights on March weather, check Zagreb weather in March.

When comparing the weather in September and April, notable differences emerge in temperature and precipitation. September boasts a warmer climate with average temperatures ranging from a chilly 3°C to a hot 34°C (18°C avg), while April starts much cooler, with temperatures dipping as low as -6°C and peaking at 29°C (12°C avg). Precipitation levels in September are higher at 98 mm over approximately 10 days, compared to April's 68 mm over 9 days. Additionally, the humidity in April is slightly higher at 72%, compared to September's 62%. For more details on April weather, you can check Zagreb weather in April.

In comparing the weather between September and May, we see some notable differences. September boasts a warmer average temperature of 18°C (64°F), with maximum temperatures reaching up to 34°C (93°F). In contrast, May has a slightly cooler average of 16°C (62°F) and a maximum of 31°C (89°F). Precipitation is also more frequent in May, with 120 mm (4.7 in) falling over 17 days, compared to September’s 98 mm (3.9 in) spread across just 10 days. Additionally, May tends to be more humid, averaging 70%, compared to September's 62%. For more details, you can check Zagreb weather in May.

In comparing the weather of September and June, September tends to be cooler overall, with average temperatures ranging from a minimum of 3°C (38°F) to a maximum of 34°C (93°F), while June offers warmer conditions with temperatures between 8°C (47°F) and 37°C (99°F). Both months experience similar precipitation levels, with September receiving 98 mm (3.9 in) over approximately 10 days, while June has slightly less at 96 mm (3.8 in) across 12 days. Humidity is also a factor, as June has a higher average at 69%, compared to September's 62%. For more detailed information on June weather, visit Zagreb weather in June.

In comparing the weather between September and July, July typically offers warmer temperatures, with an average of 23°C (74°F) compared to September's 18°C (64°F). July also sees higher maximum temperatures, peaking at 36°C (97°F), while September reaches a maximum of 34°C (93°F). However, September often experiences more precipitation, averaging 98 mm (3.9 in) over 10 rainy days, compared to July's 88 mm (3.5 in) over 11 days. Despite these differences, both months maintain similar humidity levels, around 62% in September and 64% in July. For more detailed weather information about July, you can visit Zagreb weather in July.

In comparing the weather between September and August, we see distinct differences in temperature and humidity. September experiences a wider temperature range with a minimum of 3°C (38°F) and a maximum of 34°C (93°F), resulting in a comfortable average of 18°C (64°F). In contrast, August is noticeably warmer, with temperatures ranging from a minimum of 9°C (49°F) to a peak of 39°C (103°F) and an average of 23°C (74°F). Additionally, September has more precipitation—98 mm (3.9 in) over 10 days—compared to August's 74 mm (2.9 in) on the same number of days. Furthermore, humidity levels are higher in September at 62%, while August maintains a lower level of 51%. For a detailed look at the weather during August, you can visit Zagreb weather in August.

September offers a warm transition into autumn, with temperatures ranging from a chilly 3°C (38°F) at night to a hot 34°C (93°F) during the day, accompanied by an average temperature of 18°C (64°F). It experiences more moderate precipitation of 98 mm (3.9 in) over about 10 days, with a humidity level of 62%. In contrast, October brings a notable drop in temperatures, with nighttime lows reaching 0°C (32°F) and daytime highs peaking at 27°C (80°F), resulting in a cooler average of 12°C (55°F). While October sees slightly less rainfall at 84 mm (3.3 in) across 9 days, the humidity increases to 81%, contributing to a more crisp and damp atmosphere. For more detailed information about October, check out Zagreb weather in October.

September and November present quite contrasting weather patterns. In September, temperatures range from a minimum of 3°C (38°F) to a maximum of 34°C (93°F), with an average of 18°C (64°F), making it a month with generally warm conditions. The humidity stands at 62%, and the month experiences about 98 mm (3.9 in) of precipitation across 10 days. In contrast, November sees a significant drop in temperatures, with minimums reaching -5°C (24°F), and an average of just 7°C (46°F), peaking at 22°C (71°F). This month also has a higher humidity level of 87%, along with slightly less precipitation at 89 mm (3.5 in), occurring over the same number of days. For more detailed information, you can check Zagreb weather in November.

September and December exhibit contrasting weather patterns. In September, temperatures range from a mild 3°C (38°F) at night to a warm average of 18°C (64°F) during the day, peaking at a hot 34°C (93°F). Rainfall is a common occurrence, with 98 mm (3.9 in) falling over 10 days, and humidity sits at a comfortable 62%. In stark contrast, December experiences much colder temperatures, with minimums plunging to -6°C (21°F) and an average of just 3°C (38°F), capping at a mild 19°C (66°F). Precipitation decreases slightly to 86 mm (3.4 in) over the same number of days, but humidity rises to 88%, adding to the chill. For more details, check out Zagreb weather in December.

Compare Zagreb's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Zagreb

As summer gracefully fades into autumn, September in Zagreb offers a delightful transition marked by warm days and cool evenings, setting it apart from the preceding months. The city basks in a pleasant average temperature, where the days can occasionally soar high, providing a last taste of summer warmth. While rainfall increases slightly with occasional showers, the humidity remains moderate, allowing for comfortable outdoor exploration. This month truly captures the essence of change, making it an ideal time to experience Zagreb’s vibrant culture and stunning landscapes. For a detailed overview of the climate trends throughout the year, visit Zagreb Climate.