September Weather in Dortmund, Germany

Last updated: February 26, 2025

In September, Dortmund experiences a delightful transition from the warmth of summer to the crispness of autumn. With maximum temperatures reaching up to 31°C (88°F), the month can still feel quite balmy, while the average temperature settles around 15°C (59°F), offering a comfortable climate for outdoor activities. However, don't forget to prepare for cooler moments as temperatures can dip to a chilly 1°C (35°F). Rain is a frequent visitor, with 68 mm (2.7 in) of precipitation spread over 11 days, contributing to the region's lush greenery. Humidity levels hover around 81%, providing a refreshing ambiance that encapsulates the essence of early fall in this vibrant German city.

September Temperature in Dortmund

In September, Dortmund experiences a pleasant transition from summer to autumn. With minimum temperatures hovering around 1°C (35°F) and average highs reaching a comfortable 31°C (88°F), the month showcases the last of summer's warmth while hinting at the cooler days to come. As the average temperature settles at 15°C (59°F), visitors can enjoy outdoor activities in a crisp atmosphere, unencumbered by the sweltering heat of the preceding months. This blend of mild warmth and cool breezes makes September an ideal time to experience the vibrant charm of the city before it fully embraces the autumn chill.

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

The chart illustrates September temperature patterns in Dortmund, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec373944495665666659534440
Data source: Temperature data for Dortmund 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 Dortmund

In September, Dortmund experiences a shift in its precipitation patterns, recording an average of 68 mm (2.7 in) of rain over 11 days. This represents a decrease from the wetter summer months, such as July with its 98 mm and August with 82 mm. While the total rainfall marks a notable step downwards, September's showers often bring a refreshing end to the summer heat, paving the way for the crispness of autumn. As the month transitions, rainfall becomes less frequent yet more significant, hinting at the approaching wetter months of October and December. Overall, September stands out as a bridge between the vibrant summer and the cooler, rainier fall, making it a unique time in Dortmund’s climatic journey.

September Precipitation Trends in Dortmund

The chart displays monthly precipitation patterns in Dortmund, 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.
JanFebMarAprMayJunJulAugSepOctNovDec7884853973709882689559104
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Dortmund

As summer fades into autumn, September humidity in Dortmund, Germany, experiences a notable shift, rising to 81%. This increase rejuvenates the air after the drier months of July and August, which recorded their lowest humidity levels at 72% and 71%, respectively. Compared to the early months of the year, such as January and February with humidity levels of 91% and 90%, September serves as a bridge between the drier summer and the more humid fall months ahead. As the year progresses, humidity continues to climb, peaking again in November and December, reminding us of Dortmund's characteristic damp climate.

September Average Humidity in Dortmund

This chart illustrates the average monthly humidity levels in Dortmund, 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.
JanFebMarAprMayJunJulAugSepOctNovDec91%90%87%84%77%74%72%71%81%88%91%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Dortmund

As summer transitions to autumn in Dortmund, Germany, the UV Index begins to decline. In September, the UV Index stands at a moderate 5, indicating a decreased risk of harm from unprotected sun exposure compared to the peak summer months. With a burn time of 30 minutes, it's still wise to enjoy the outdoors with some sun protection, particularly during midday when UV rays are strongest. This trend of a tapering UV Index continues into October, emphasizing the importance of monitoring UV levels as the seasons change. Stay informed about daily variations by checking the Dortmund UV Index.

Maximum UV Index Levels in Dortmund for September

The chart shows the monthly maximum UV Index (UVI) for Dortmund 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.
JanFebMarAprMayJunJulAugSepOctNovDec124578875421
Data source: Dortmund 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 Dortmund

As September rolls into Dortmund, Germany, the city basks in a golden embrace of 315 hours of sunshine, a notable glow following the vibrant summer months. This shift marks a gradual transition from the peak warmth of July and August, where the sun generously showered the region with over 400 hours of radiant light. Despite this decrease, the month retains a significant amount of sunny days, helping to bridge the gap before the cooler months set in. As we reflect on the journey from the 100 hours of brightness in January to the lush 385 hours of May, September stands out as a pivotal moment where warmer hues linger just a little longer, allowing for a final celebration of outdoor activities before autumn takes hold.

Monthly Sunshine Duration in Dortmund: September Highlighted

The September sunshine duration represents the total number of hours Dortmund 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.
JanFebMarAprMayJunJulAugSepOctNovDec100h195h257h346h385h385h403h379h315h229h172h115h
Data source: Dortmund September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Dortmund During September

In September, Dortmund experiences a 35% chance of sunny weather, reflecting a trend of moderate sunshine as summer transitions into autumn. This likelihood is relatively stable when compared to the preceding summer months, which hover around 28% to 32%. The month marks a subtle increase from August, suggesting that as the warmth of summer lingers, residents can still enjoy a fair number of sunny days. However, as the year progresses towards winter, this optimism begins to dwindle, with probabilities dropping significantly in the following months. Overall, September offers a pleasant window for outdoor activities, bridging the gap between the vibrant summer and the cooler fall season.

Percentage of Sunny Days in September in Dortmund

The chart illustrates the percentage of sunny days in Dortmund 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 Dortmund experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec10%27%38%35%28%28%29%32%35%26%20%15%
Data source: Dortmund September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Dortmund in September

As summer gently fades in September, Dortmund experiences a delightful transition in daylight duration, with the sun gracing the city for about 12 hours each day. This marks a gradual decrease from the peak of 16 hours enjoyed in the height of summer, reflecting the onset of autumn. Following the vibrant summer months, where daylight reaches its zenith in June and July, September offers a still generous amount of sunlight, bridging the lush abundance of summer with the cooler days that lie ahead. As the city prepares for the shorter days of October, the fading light in September invites residents to savor outdoor moments amid the changing colors of nature, making it a perfect time for reflection and appreciation of the seasons.

Average Daylight Hours in Dortmund for September

The chart illustrates the variation in daylight duration in Dortmund throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 23m9h 58m11h 54m13h 54m15h 38m16h 33m16h 4m14h 30m12h 35m10h 36m8h 50m7h 53m
Data source: Dortmund daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Dortmund

As September sweeps in, Dortmund experiences a gentle shift in wind patterns, with an average speed of 2.7 m/s (6 mph), marking one of the calmer months of the year. This lull follows the summer, where wind speeds hover slightly higher, peaking in May at 4.0 m/s (9 mph). Interestingly, September's winds are noticeably lighter than those of its predecessor, August, which recorded a speed of 3.2 m/s (7 mph). This trend of diminishing wind speeds increasingly sets the tone for autumn, as October sees a resurgence with winds picking up again to 4.4 m/s (10 mph). Overall, September serves as a serene interlude, allowing for a moment of tranquility before the winds of change return.

Average September Wind Speed in Dortmund

The chart displays monthly wind speed patterns in Dortmund, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.14.13.73.14.02.62.83.22.7 m/s4.43.43.9
Data source: Dortmund September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Dortmund Compares to Other Months

The weather in Dortmund 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 Dortmund and find detailed weather information for every month.

September and January exhibit stark contrasts in weather patterns. In September, temperatures range from a mild 1°C (35°F) at night to a warm 31°C (88°F) during the day, with an average of 15°C (59°F). This month also sees moderate rainfall, totaling 68 mm (2.7 in) over about 11 days, and a humidity level of 81%. In contrast, January is much cooler, with minimum temperatures dropping to -9°C (16°F), averaging around 3°C (38°F), and reaching a maximum of 14°C (57°F). The precipitation slightly increases to 78 mm (3.1 in) over approximately 14 days, accompanied by higher humidity at 91%. For a detailed look at January weather, you can check this link: Dortmund weather in January.

September and February present striking contrasts in weather. September sees warmer temperatures, with a minimum of 1°C (35°F) and a comfortable average of 15°C (59°F), peaking at 31°C (88°F). In contrast, February is significantly colder, with minimum temperatures plunging to -16°C (3°F) and an average of just 4°C (40°F), although it does reach a maximum of 20°C (67°F) on warmer days. Precipitation levels are also notable, with September experiencing 68 mm (2.7 in) across 11 rainy days, while February records slightly more at 84 mm (3.3 in) over 13 days. Additionally, humidity in February tends to be higher, averaging at 90%, compared to September's 81%. For more detailed information about February weather, check out Dortmund weather in February.

The weather in September typically features a more comfortable temperature range, with minimums around 1°C (35°F), averaging 15°C (59°F), and reaching a maximum of 31°C (88°F). This month sees a total precipitation of 68 mm (2.7 in) over about 11 days, accompanied by a humidity level of 81%. In contrast, March experiences cooler temperatures, starting with a minimum of -9°C (16°F), averaging 6°C (44°F), and peaking at 22°C (72°F). This month has slightly higher precipitation at 85 mm (3.4 in) over 15 days and a humidity level of 87%. For more detailed insights into the climate during this time, check out Dortmund weather in March.

September and April present quite different weather experiences. In September, temperatures range from a chilly 1°C (35°F) at night to a warm 31°C (88°F) during the day, with an average of 15°C (59°F). The month sees an average of 68 mm (2.7 in) of precipitation over 11 days, with humidity levels around 81%. In contrast, April typically starts off cooler, with minimum temperatures dropping to -4°C (25°F) and daytime highs reaching 28°C (82°F), culminating in an average of 10°C (50°F). It experiences less rainfall, totaling 39 mm (1.6 in) over 9 days and slightly higher humidity at 84%. For more specifics on the weather in April, you can check Dortmund weather in April.

In comparing the weather between September and May, both months display a range of temperatures, but September generally experiences slightly warmer conditions. September temperatures range from a minimum of 1°C (35°F) to a maximum of 31°C (88°F), with an average of 15°C (59°F). In contrast, May has temperatures that span from a minimum of 0°C (33°F) to a maximum of 33°C (91°F), averaging 13°C (56°F). When it comes to precipitation, September receives about 68 mm (2.7 in) over 11 days, while May sees a bit more at 73 mm (2.9 in) across 13 days. Humidity is also a factor, with September being slightly more humid at 81% compared to May's 77%. For more detailed information, you can visit Dortmund weather in May.

In September, the weather presents a broader temperature range, with minimums dropping to 1°C (35°F) and maximums reaching 31°C (88°F), which creates more variability compared to June. The average temperature in September is milder at 15°C (59°F) than June's 18°C (66°F). Both months experience similar precipitation levels, with September receiving 68 mm (2.7 in) over 11 days, while June has slightly higher rainfall at 70 mm (2.7 in) over 10 days. Humidity is higher in September at 81% compared to June's 74%, contributing to a more humid feel as summer transitions into fall. For a detailed look at June weather patterns, visit Dortmund weather in June.

When comparing the weather in September to that in July, it's evident that September experiences a broader temperature range. September can see minimum temperatures drop to around 1°C (35°F), while July maintains a higher baseline with a minimum of 8°C (47°F). The average temperatures also reflect this contrast, with September averaging 15°C (59°F) compared to July's 19°C (66°F). However, July is typically hotter overall, with maximum temperatures reaching up to 38°C (100°F), whereas September's maximum peaks at a lower 31°C (88°F). Precipitation is more frequent in July, with 98 mm (3.9 in) of rain over 14 days, compared to September's 68 mm (2.7 in) over 11 days. Additionally, September has a higher humidity level at 81%, compared to July's 72%. For more detailed insights, you can check Dortmund weather in July.

September's weather presents a notable shift compared to August, with average temperatures dipping from 19°C (66°F) in August to 15°C (59°F). While September experiences a more expansive temperature range, with minimums of 1°C (35°F) and maximums reaching 31°C (88°F), it contrasts with August’s warmer evenings and highs of 36°C (97°F). Precipitation levels slightly decrease in September to 68 mm (2.7 in) over 11 days, compared to August’s 82 mm (3.2 in) over 15 days. Additionally, September's humidity rises to 81%, surpassing August’s 71%, making it feel a bit more humid despite the cooler temperatures. For more detailed insights, check out the Dortmund weather in August.

When comparing the weather between September and October, we see a notable shift in temperatures and precipitation patterns. September typically features a wider range of temperatures, with minimums reaching 1°C (35°F) and maximums peaking at 31°C (88°F), resulting in an average of 15°C (59°F). In contrast, October brings cooler temperatures, with a minimum of 0°C (33°F) and a maximum of 26°C (80°F), lowering the average to 12°C (53°F). Precipitation also increases in October, totaling 95 mm (3.7 in) over about 15 days, compared to September's 68 mm (2.7 in) over 11 days. Humidity levels rise slightly, reaching 88% in October from 81% in September. For more detailed insights into October weather, check out Dortmund weather in October.

September and November present contrasting weather conditions, reflecting the transition from summer to winter. In September, temperatures range from a minimum of 1°C (35°F) to a maximum of 31°C (88°F), with an average of 15°C (59°F) and relatively high humidity at 81%. During this month, there are typically 11 days of precipitation, totaling 68 mm (2.7 in). In contrast, November sees colder temperatures with a minimum of -5°C (23°F) and a maximum of 19°C (67°F), resulting in an average of 7°C (44°F). This month experiences slightly less precipitation at 59 mm (2.3 in) over 13 days, but humidity increases to 91%, creating a chillier and more damp atmosphere. For more detailed information on what to expect, you can explore Dortmund weather in November.

September and December present contrasting weather conditions. In September, temperatures range from a mild 1°C (35°F) to a warm 31°C (88°F), with an average of 15°C (59°F), making it a more comfortable month overall. In contrast, December sees colder temperatures, featuring a minimum of -7°C (20°F) and a maximum of 15°C (59°F), with an average of just 5°C (40°F). Additionally, December experiences more precipitation, totaling 104 mm (4.1 in) over 19 days, compared to September's 68 mm (2.7 in) across 11 days. The humidity also rises in December to 92%, compared to 81% in September. For more details, check out this link: Dortmund weather in December.

Compare Dortmund's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Dortmund

As summer gradually gives way to autumn, September in Dortmund presents a unique transition in weather characteristics. With maximum temperatures peaking pleasantly at 31°C and a notable dip to cooler averages, the month showcases an inviting warmth yet also harbors the potential for crisp mornings and chilly evenings. The elevated humidity of 81% coupled with about 11 days of precipitation adds an element of unpredictability, distinguishing September from the sun-drenched summer months. For those yearning to explore what the weather holds, this month can be a delightful blend of both lingering heat and refreshing fall breezes. Discover more insights and specifics about the Dortmund Climate to enhance your understanding of this intriguing seasonal shift.