September Weather in Gdansk, Poland

Last updated: August 27, 2025

In September, Gdansk, Poland experiences a dynamic shift in weather, characterized by a maximum temperature reaching 31°C (88°F), making it one of the warmer months. The average temperature settles at a pleasant 15°C (59°F), while nighttime can bring a chill with minimums dipping to 4°C (39°F). Visitors and locals alike should prepare for some rain, as 68 mm (2.7 in) of precipitation falls over approximately 10 days, contributing to a humidity level that averages around 81%. This mixture of warm days and cool nights, combined with frequent showers, creates a unique backdrop for enjoying the vibrant autumnal landscapes of the city.

September Temperature in Gdansk

As September rolls into Gdansk, temperatures begin to shift from the summer's warmth, yet remain pleasantly mild. With average lows around 4°C (39°F) and highs reaching as much as 31°C (88°F), this month offers a delightful transition into autumn. The average temperature of 15°C (59°F) suggests a perfect balance for outdoor activities, making it an ideal time for exploring the city's rich history and vibrant culture. Interestingly, while the heat tapers off from the scorching highs of July and August, September still boasts comfortably warm days, inviting locals and tourists alike to bask in the fading summer sun before cooler weather sets in.

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

The chart illustrates September temperature patterns in Gdansk, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Gdansk, 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).
JanFebMarAprMayJunJulAugSepOctNovDec333338465464666659514335
Data source: Temperature data for Gdansk 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 Gdansk

In September, Gdańsk experiences a notable shift in weather patterns, as the precipitation amount reaches 68 mm (2.7 in) over approximately 10 days of rain. This figure reflects a slight decrease from the previous summer months, where July and August saw higher totals of 98 mm and 71 mm, respectively. As early autumn settles in, the falling precipitation signals a transition period, hinting at the cooler and wetter months ahead. The consistent rain during September continues the trend noticed since May, where a rise in rainy days throughout the summer months has set the stage for a moist early fall. This increase suggests a steady rhythm of rainfall that characterizes Gdańsk’s vibrant weather patterns, emphasizing its location by the Baltic Sea.

September Precipitation Trends in Gdansk

The chart displays monthly precipitation patterns in Gdansk, 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 Gdansk, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec423641376967987168623948
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Gdansk

In Gdansk, Poland, September experiences a notable shift in humidity, with levels averaging 81%. This marks a slight increase from the drier summer months of June, July, and August, which maintain a consistent 76% humidity. The transition into autumn begins to emerge as the humidities rise once more, inching closer to winter's damp embrace that brings much higher percentages, peaking at 89% in November and December. The trend illustrates a gradual return to the more humid conditions characteristic of the colder months, offering a glimpse into the shifting seasons as Gdansk prepares for the crisp terminal months of the year.

September Average Humidity in Gdansk

This chart illustrates the average monthly humidity levels in Gdansk, 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 Gdansk is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec90%89%88%84%77%76%76%76%81%86%89%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Gdansk

In September, Gdansk experiences a moderate UV Index of 5—a slight decline from the summer peak but still requiring caution outdoors. With a burn time of 30 minutes, this month marks a transition as the sun’s intensity begins to wane. As daylight shortens and autumn draws near, September presents a fantastic opportunity for outdoor activities, but remember to protect your skin, especially during midday hours. For more detailed information on UV levels throughout the year, check out the Gdansk UV Index.

Maximum UV Index Levels in Gdansk for September

The chart shows the monthly maximum UV Index (UVI) for Gdansk 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 Gdansk typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124567765311
Data source: Gdansk 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 Gdansk

September in Gdańsk offers a beautiful transition from the sun-drenched summer months to the cooler autumn days, with an impressive 308 hours of sunshine. This marks a noticeable decline from the peak of June's 447 hours, yet still radiates warmth compared to the more subdued winter months ahead. As summer fades, September provides a gentle reminder of the vibrant light experienced in May and June, while remaining significantly sunnier than the darker months of October and November. Visitors can revel in the lingering sunshine, savoring the playful blend of summer warmth and autumn crispness, before the days shorten into the colder season.

Monthly Sunshine Duration in Gdansk: September Highlighted

The September sunshine duration represents the total number of hours Gdansk 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.
JanFebMarAprMayJunJulAugSepOctNovDec99h191h261h354h419h447h433h392h308h240h153h125h
Data source: Gdansk September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Gdansk During September

As summer transitions into autumn, September in Gdansk brings a moderate 35% chance of sunny weather. While this isn't the sunniest month of the year, it follows the more radiant June, which boasts a robust 58% likelihood of clear skies. Interestingly, September sees a slight dip from August's 29%, indicating a gradual retreat from summer's warmth. However, the sun's presence is still a valued companion before the cooler months set in, making it an inviting time for outdoor activities amidst the city's rich cultural offerings. Overall, while September may not promise the peak sunshine of earlier months, it provides just enough sunny moments to savor before autumn envelops Gdansk.

Percentage of Sunny Days in September in Gdansk

The chart illustrates the percentage of sunny days in Gdansk 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 Gdansk experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec10%34%38%39%39%58%39%29%35%40%18%25%
Data source: Gdansk September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Gdansk in September

As September rolls into Gdańsk, a distinct transition in daylight becomes apparent. With 12 hours of daylight, this month signals a shift from the longer summer days—where June peaks at an impressive 17 hours—to the shorter, cozier days of fall. Following the vibrant summer, where August still offers 14 hours, September's gradual decrease brings a hint of autumn's approach, leading into October's 10 hours. This natural ebb and flow of daylight not only marks the changing seasons but also invites residents and visitors to relish in the enchanting hues of early autumn, where every sunset becomes a cherished moment.

Average Daylight Hours in Gdansk for September

The chart illustrates the variation in daylight duration in Gdansk throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec7h 59m9h 45m11h 53m14h 5m16h 2m17h 4m16h 31m14h 46m12h 38m10h 27m8h 29m7h 24m
Data source: Gdansk daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Gdansk

As summer transitions into autumn, September in Gdansk experiences a shift in wind patterns, with an average speed of 4.0 m/s (9 mph). This steady breeze mirrors the gentle gusts felt throughout the summer months, which saw similar conditions with an average of 3.4 m/s in July and 4.0 m/s in August. However, as the city anticipates the crispness of October, when winds pick up to 4.9 m/s (11 mph), September offers a delightful balance. The wind, though mild, carries hints of the seasonal change ahead, reminding residents and visitors alike that the vibrant hues of autumn are just around the corner.

Average September Wind Speed in Gdansk

The chart displays monthly wind speed patterns in Gdansk, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.34.54.44.34.33.33.44.04.0 m/s4.94.74.9
Data source: Gdansk September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Gdansk Compares to Other Months

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

When comparing the weather in September and January, distinct contrasts emerge. September experiences a temperature range from a cool minimum of 4°C (39°F) to a warm maximum of 31°C (88°F), with an average of 15°C (59°F) and relatively high humidity at 81%. This month also sees about 68 mm (2.7 in) of precipitation over approximately 10 days. In stark contrast, January offers a much colder climate, with temperatures dipping to a minimum of -16°C (3°F) and reaching a maximum of 11°C (51°F), culminating in an average of 1°C (34°F). Precipitation is lower at 42 mm (1.6 in), spread over 11 days, and humidity is slightly higher at 89%. For more insights on the winter weather, you can refer to Gdansk weather in January.

In September, the weather is considerably warmer, with temperatures ranging from a low of 4°C (39°F) to a high of 31°C (88°F), averaging at 15°C (59°F). This month also experiences more precipitation, totaling 68 mm (2.7 in) over about 10 days, while humidity levels are around 81%. In contrast, February brings much colder conditions, with temperatures varying from -16°C (3°F) to 13°C (56°F), averaging just 1°C (33°F). Precipitation is lower in February, at 36 mm (1.4 in) over 9 days, but with higher humidity levels of 89%. For more details on the weather during this chilly month, check Gdansk weather in February.

In comparing the weather between September and March, we see a striking contrast in temperatures and conditions. September enjoys a mild climate with average temperatures around 15°C (59°F), peaking at a warm 31°C (88°F), while March is significantly colder, averaging just 3°C (38°F) and reaching a maximum of 18°C (64°F). Precipitation levels are also different; September has 68 mm (2.7 in) spread over about 10 days, whereas March sees less at 41 mm (1.6 in) but over 12 days. Furthermore, humidity is higher in March at 88% compared to September's 81%. For a more detailed look at March weather, check out Gdansk weather in March.

September and April present contrasting weather patterns as the seasons shift. In September, temperatures range from a cool 4°C (39°F) at night to a warm 31°C (88°F) during the day, with an average of 15°C (59°F). Meanwhile, April starts off much chillier, with nighttime lows dipping to -5°C (24°F) and a daytime maximum of 26°C (78°F), averaging 8°C (46°F). Precipitation is more abundant in September, totaling 68 mm (2.7 inches) over about 10 days, compared to April's 37 mm (1.5 inches) across 8 days. Both months have high humidity levels, with September at 81% and April slightly higher at 84%. For more information, check out Gdansk weather in April.

In comparing the weather of September and May, we see notable differences in temperature and precipitation patterns. September generally has a wider temperature range, with minimums of 4°C (39°F) and maximums reaching up to 31°C (88°F), leading to a warmer average of 15°C (59°F). In contrast, May starts cooler, with minimum temperatures around -1°C (31°F) and an average of 12°C (54°F), though it still enjoys pleasant highs of 29°C (84°F). Precipitation levels are quite similar, with September receiving 68 mm over roughly 10 days and May seeing slightly more at 69 mm across 13 days, but humidity is slightly higher in September at 81% compared to May’s 76%. For those planning a visit, detailed information can be found in the guide: Gdansk weather in May.

September and June both offer diverse weather conditions, though September tends to have slightly cooler temperatures overall. In September, the temperatures range from a minimum of 4°C (39°F) to a maximum of 31°C (88°F), with an average of 15°C (59°F), while June sees temperatures from 5°C (40°F) to 33°C (91°F), with an average of 18°C (65°F). Both months experience similar levels of precipitation, around 67-68 mm, and approximately 10 rainy days. However, September has a higher humidity level at 81% compared to June's 76%. For more information, you can check Gdansk weather in June.

September weather in Gdańsk exhibits a wider range of temperatures compared to July, with minimums dipping down to 4°C (39°F) and maximums reaching up to 31°C (88°F). The average temperature for September is around 15°C (59°F), which is cooler than July's average of 19°C (66°F). Rainfall also varies, with September experiencing 68 mm (2.7 in) of precipitation over about 10 days, whereas July sees 98 mm (3.9 in) over 13 days. Notably, September has a higher humidity level of 81% compared to July's 76%. For more detailed information on July's weather, you can visit Gdansk weather in July.

September weather shows a notable shift from August, with cooler minimum temperatures dipping to 4°C (39°F) compared to August's minimum of 7°C (45°F). While the average maximum in September reaches 31°C (88°F), it is only slightly lower than August’s maximum of 32°C (90°F). Precipitation remains relatively consistent between the two months, with September receiving 68 mm (2.7 in) over 10 days, while August sees just a bit more at 71 mm (2.8 in) over 12 days. Interestingly, September has higher humidity at 81%, compared to August's 76%. Overall, September introduces cooler temperatures and slightly increased humidity, making it feel quite different from the summer warmth of August. For a more detailed look at what to expect, check out Gdansk weather in August.

September and October weather show a notable transition as autumn sets in. In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 31°C (88°F), with an average of 15°C (59°F). The month experiences about 68 mm (2.7 in) of precipitation across ten days, and humidity is at a comfortable 81%. In contrast, October sees a drop in temperatures, with lows reaching 0°C (32°F) and a maximum of 23°C (73°F), averaging 10°C (51°F). Precipitation slightly decreases to 61 mm (2.4 in) over twelve days, while humidity rises to 86%. This shift indicates a cooler, wetter atmosphere as September gives way to October. For more detailed information, check out Gdansk weather in October.

In September, the weather is much warmer, with temperatures ranging from a chilly 4°C (39°F) at night to a warm 31°C (88°F) during the day, and an average temperature of 15°C (59°F). The month sees higher precipitation at 68 mm (2.7 in) over 10 days, accompanied by humidity levels around 81%. In contrast, November brings a significant drop in temperatures, experiencing a minimum of -4°C (25°F) and a maximum of 16°C (61°F), with an average temperature of just 6°C (43°F). The precipitation decreases to 39 mm (1.5 in) also spread over 10 days, while humidity rises slightly to 89%. For more details on November weather, you can visit this link: Gdansk weather in November.

September and December present stark contrasts in weather conditions. In September, temperatures are mild, with a minimum of 4°C (39°F) and an average of 15°C (59°F), peaking at a warm 31°C (88°F). This month experiences about 68 mm (2.7 in) of precipitation over approximately 10 days, along with a humidity level of 81%. In contrast, December sees much colder conditions, with temperatures dropping to a minimum of -11°C (12°F) and an average of just 2°C (36°F), reaching a maximum of 10°C (51°F). While precipitation in December is slightly lower at 48 mm (1.9 in), it occurs over more days, totaling about 12, and humidity rises to 89%. For more detailed information, you can refer to Gdansk weather in December.

Compare Gdansk's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Gdansk

As summer begins to fade, September in Gdansk offers a refreshing transition marked by cooler temperatures and increased humidity. Unlike the sweltering highs often experienced in July and August, September sees averages that are notably milder, making it a more comfortable time for outdoor activities. While the month can still surprise with warm days reaching up to 31°C (88°F), it also brings the chance of early autumn rain, contributing to a total precipitation of 68 mm (2.7 in) over about 10 days. Whether you’re exploring the city’s rich history or enjoying its natural beauty, September's unpredictable weather invites layers and adaptability, creating a unique travel experience. For a deeper insight into Gdansk’s shifting seasons, visit Gdansk Climate.