Last updated: February 26, 2025
September in Heidelberg, Germany offers a captivating blend of warm and cool weather. With maximum temperatures soaring to 31°C (89°F) alongside an average of 16°C (61°F), visitors can enjoy pleasant days, though evenings may bring a chill with lows dipping to 4°C (39°F). Rainfall is moderate, with 58 mm (2.3 in) experienced over 8 days, contributing to the region's lush scenery. The month also sees an 85% humidity level, enriching the vibrant atmosphere, making it a delightful time to explore the city's historic charm and natural beauty.
In September, Heidelberg experiences a delightful transition as summer begins to wane. With temperatures ranging from a morning minimum of 4°C (39°F) to a pleasantly warm maximum of 31°C (89°F), the month boasts an average of 16°C (61°F) that invites both locals and tourists to bask in its glorious autumn charm. This month notably bridges the warm highs of August and the cooler beginnings of fall in October, indicative of an overall trend from soaring summer temperatures down to the refreshing coolness of autumn. As the days shorten and the leaves start to turn, September serves as a bridge, offering a perfect blend of warmth and the crispness of the season to come.
September in Heidelberg sees a noticeable transition as summer wanes, with precipitation averaging 58 mm (2.3 in) over approximately 8 days of rain. This marks a slight decrease from August, which recorded 60 mm (2.4 in) over a greater number of rainy days, indicating a trend toward less frequent but consistent showers as autumn approaches. The month sets the tone for October's typical uptick in rainfall, where the average rises to 74 mm (2.9 in) with 13 rainy days. Overall, September's precipitation subtly primes the landscape for the changes ahead, reinforcing Heidelberg's rich tapestry of seasonal weather patterns.
In September, Heidelberg experiences a notable increase in humidity, with levels reaching 85%—a slight rise from the previous month. This uptick marks a transition from the relatively drier summer months of July and August, which hover between 83% and 84%. As autumn approaches, the humidity remains consistently elevated, reflecting a gradual climb from the drier conditions of spring and early summer. Notably, this trend culminates in the even higher humidity figures of October and November, illustrating how Heidelberg’s weather shifts towards a more moisture-laden atmosphere as the year draws to a close.
As summer transitions to autumn in Heidelberg, the UV Index begins to decline, reflecting a shift in sun intensity and solar exposure. In September, the UV Index holds steady at 6, categorizing it as high, which means that while the sun's rays are still strong, they are less intense than in the peak months of June through August, when the index reached a maximum of 8. This shift allows for a burn time of 25 minutes, reminding residents and visitors alike to remain cautious. As the month progresses, the UV Index continues to decrease, leading into the cooler months of October and November. For more detailed insights, visit Heidelberg UV Index.
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As summer gently gives way to autumn, September in Heidelberg continues to bask in a generous 321 hours of sunshine. While the days grow shorter compared to the vibrant months of July and June, which boast over 390 hours, September still shines brighter than October’s 258 hours. This transitional month offers a lovely balance, allowing residents and visitors to enjoy the fading warmth amid the stunning fall foliage. The trend indicates a gradual retreat of sunshine as the year progresses, yet September stands out as a delightful bridge between the glorious summer and the quieter autumn days, inviting all to relish the last golden rays of the season.
As we transition into September in Heidelberg, Germany, the likelihood of sunny weather showcases a notable resurgence, with a 43% chance of sunshine. This marks a subtle rise from the summer months, where the sunniest days lingered at around 30% to 38%. September stands out as a beacon of brighter skies, offering a more favorable climate compared to the early fall, where the sun's presence dwindles in October and November, dropping to 33% and 20%, respectively. Thus, September graces residents and visitors alike with a pleasant balance of warmth and brightness, making it an ideal time to enjoy the vibrant fall landscape before winter's chill sets in.
As summer transitions to autumn, September in Heidelberg showcases a gentle decline in daylight, with the sun gracing the sky for approximately 12 hours. This marks a notable shift from the prolonged 16 hours of daylight experienced in June, illustrating the natural ebb of sunlight as the year progresses. The month starts robustly, retaining some of the summer's warmth and brightness, yet the daylight hours steadily taper off, hinting at the coming chill of October. With a balanced blend of light and shadow, September invites residents to savor the lingering warmth of late summer while anticipating the cozy embrace of autumn.
As September settles in Heidelberg, the winds begin to soften, with an average speed of just 2.0 m/s (4 mph)—the gentlest of the year. This marks a notable drop from the breezier months of late spring and early summer, where May and June experience higher gusts around 3.5 m/s (8 mph) and 2.1 m/s (5 mph), respectively. As the vibrant colors of autumn slowly replace summer's green, the tranquil winds provide a serene backdrop for the changing season, echoing the overall decline in wind intensity that starts in April and continues through the fall. The shift is palpable, offering a calm reprieve as Heidelberg prepares for the crisp air of October, which sees a slight uptick back to 2.6 m/s (6 mph). This gentle transition not only enriches the scenic beauty of the city but also embodies the harmonious rhythm of nature's cycles.
The weather in Heidelberg 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 Heidelberg and find detailed weather information for every month.
In September, the weather is generally milder, with temperatures ranging from a minimum of 4°C (39°F) to a maximum of 31°C (89°F) and an average of 16°C (61°F). The month sees 58 mm (2.3 in) of precipitation spread over about 8 days, with humidity levels at 85%. In contrast, January brings much colder temperatures, with a minimum of -13°C (9°F) and a maximum of 13°C (55°F), averaging just 2°C (36°F). This month experiences higher precipitation at 78 mm (3.1 in), falling over 13 days, and higher humidity at 91%. For more specific insights into January’s conditions, you can check out Heidelberg weather in January.
In September, temperatures range significantly from a cool 4°C (39°F) to a warm 31°C (89°F), making it a month of transition with an average of 16°C (61°F). In contrast, February is characterized by much colder conditions, with temperatures dipping as low as -10°C (14°F) and averaging just 4°C (39°F). Additionally, September experiences 58 mm (2.3 in) of precipitation over about 8 days, while February sees slightly more rain at 72 mm (2.8 in) across 11 days, contributing to the higher humidity levels typical of this winter month at 89%. For more details, check out Heidelberg weather in February.
When comparing the weather in September and March, it's clear that the two months present distinct climates. September enjoys a milder temperature range with minimums of 4°C (39°F) and maximums reaching up to 31°C (89°F), averaging around 16°C (61°F). In contrast, March sees much cooler temperatures, with lows of -10°C (15°F) and highs capped at 23°C (73°F), averaging only 6°C (44°F).
In terms of precipitation, March experiences more rain, accumulating 92 mm (3.6 in) over 14 days, while September has 58 mm (2.3 in) over 8 days. Both months exhibit similar humidity levels, with September at 85% and March slightly higher at 87%. For more detailed information, you can check out the link: Heidelberg weather in March.
September and April exhibit distinct weather patterns that highlight the transition between seasons. In September, temperatures can range from a minimum of 4°C (39°F) to a maximum of 31°C (89°F), with an average of 16°C (61°F). The month experiences higher humidity at 85% and slightly more precipitation at 58 mm (2.3 in), spread over 8 days. In contrast, April's temperatures are cooler, dipping to a minimum of -4°C (25°F) and reaching a maximum of 27°C (80°F), averaging around 10°C (51°F). The month is characterized by less precipitation at 35 mm (1.4 in) while maintaining a similar number of rainy days. For more detailed insights, you can explore Heidelberg weather in April.
September and May present distinct weather patterns, shaping the climate experience in those months. In September, temperatures range from a cool minimum of 4°C (39°F) to a warmer average of 16°C (61°F), with maximums reaching up to 31°C (89°F). The month sees about 58 mm (2.3 in) of precipitation over approximately 8 days, accompanied by high humidity at 85%. In contrast, May has lower minimum temperatures, starting at 0°C (32°F) and averaging 14°C (57°F), yet it also hits similar maximums of 31°C (88°F). Rainfall in May is higher, totaling 89 mm (3.5 in) over around 13 days, and the humidity is slightly lower at 79%. For a more detailed look at May weather, visit Heidelberg weather in May.
In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 31°C (89°F), with an average of 16°C (61°F). The month experiences around 58 mm (2.3 in) of precipitation over approximately 8 days, while humidity levels are relatively high at 85%. In contrast, June typically has warmer temperatures, with a minimum of 7°C (45°F) and a maximum of 35°C (96°F), averaging 19°C (67°F). Despite being the warmer month, June receives more precipitation, totaling 85 mm (3.4 in) over about 11 days, and maintains a slightly lower humidity of 82%. For more details, you can check Heidelberg weather in June.
When comparing the weather in September and July, we notice several distinct differences. September experiences a broader temperature range, with a minimum of 4°C (39°F) and a maximum of 31°C (89°F), while July enjoys warmer conditions, featuring a minimum of 8°C (47°F) and reaching highs of 37°C (100°F). Additionally, September has an average temperature of 16°C (61°F), which is cooler than July’s average of 20°C (68°F). Rainfall is slightly less in September, totaling 58 mm (2.3 in) over 8 days, compared to July’s 66 mm (2.6 in) across 11 days. Humidity levels remain relatively high in both months, with September at 85% and July slightly lower at 83%. For a more detailed look, check out Heidelberg weather in July.
In comparing the weather between September and August, September tends to be cooler with a minimum temperature of 4°C (39°F) and an average of 16°C (61°F), while August features higher temperatures with a minimum of 7°C (44°F) and an average of 20°C (69°F). The maximum temperature in September reaches 31°C (89°F), lower than August's peak of 36°C (96°F). While both months experience similar levels of precipitation, with September receiving 58 mm (2.3 in) over 8 days and August slightly higher at 60 mm (2.4 in) across 12 days, September's humidity is marginally higher at 85%, compared to August's 84%. For more detailed insights, you can refer to Heidelberg weather in August.
In comparing the weather between September and October, we see a noticeable transition as the days grow cooler. September boasts a wider temperature range, with minimums around 4°C (39°F) and maximums reaching up to 31°C (89°F), resulting in an average temperature of 16°C (61°F). In contrast, October's temperatures drop, with minimums dipping to 2°C (35°F) and maximums peaking at 26°C (78°F), leading to a lower average of 11°C (52°F). Precipitation also sees a rise, with October experiencing more rainfall (74 mm or 2.9 in) over more days (13) compared to September's 58 mm (2.3 in) across 8 days. Humidity levels increase slightly, reaching 88% in October versus 85% in September. For a detailed view of October's weather, you can check Heidelberg weather in October.
September and November present notably different weather patterns. In September, temperatures range from a mild 4°C (39°F) at night to a warm 31°C (89°F) during the day, averaging around 16°C (61°F). The month experiences some rain, with about 58 mm (2.3 in) of precipitation spread over 8 days and a humidity level of 85%. In contrast, November sees a significant drop in temperatures, with minimums plunging to -4°C (26°F) and an average of just 6°C (43°F). Daytime highs reach a comfortable 21°C (70°F), and precipitation levels remain similar at 57 mm (2.3 in), albeit over more days—10 in total—resulting in slightly higher humidity at 89%. For more specific details, you can check Heidelberg weather in November.
September and December showcase a stark contrast in weather conditions. In September, temperatures range from a pleasant minimum of 4°C (39°F) to a warm maximum of 31°C (89°F), averaging around 16°C (61°F). The month receives 58 mm (2.3 in) of precipitation over about 8 days, with humidity levels at 85%. In contrast, December cools down significantly, featuring a temperature range from -6°C (21°F) to a maximum of 14°C (58°F), with an average of just 4°C (39°F). This month is much wetter, accumulating 134 mm (5.3 in) of precipitation over 19 days and higher humidity at 91%. For a deeper insight into December's weather patterns, check out Heidelberg weather in December.
As summer transitions to autumn, September in Heidelberg showcases a delightful contrast to the hotter months. While the temperatures can peak at a warm 31°C, the average drops to a comfortable 16°C, marking a significant shift that invites outdoor exploration without the sweltering heat. Humidity levels remain relatively high at 85%, contributing to the refreshing feel of the crisp air, especially in the mornings. However, potential rain showers, with about 58 mm over approximately 8 days, remind us that fall is on the way. For those seeking to understand the full scope of weather patterns in Heidelberg, explore more at Heidelberg Climate.