Last updated: August 21, 2025
September in Mondorf-les-Bains, Luxembourg boasts a varied climate, with maximum temperatures reaching a warm 32°C (89°F), contrasting the cooler averages of 15°C (59°F) and dips to a low of 4°C (39°F). This month typically experiences 61 mm (2.4 in) of precipitation spread across 9 rainy days, leading to a humid environment with levels around 83%. As summer transitions into autumn, visitors can expect fluctuating weather that perfectly embodies the beauty of seasonal change in this charming spa town.
In September, Mondorf-les-Bains, Luxembourg, begins to transition into the cool embrace of autumn. With minimum temperatures around 4°C (39°F) and average highs peaking at a comfortable 32°C (89°F), the weather is pleasantly mild, making it an ideal time for outdoor activities. This month's average of 15°C (59°F) offers a gentle reminder of summer's warmth while ushering in the crispness of fall. As the month progresses, you'll notice the days shortening and the cooler nights becoming more frequent, marking a significant shift from the sweltering heat of July and August. Whether you're exploring the lush landscapes or enjoying the charming spas, September's fluctuating temperatures create a delightful backdrop for enjoying all that Mondorf-les-Bains has to offer.
September in Mondorf-les-Bains brings a moderate 61 mm (2.4 in) of precipitation, typically distributed over 9 days. This amount reflects a gentle transition into the wetter autumn months, following the drier summer, with August recording only 59 mm (2.3 in). Interestingly, as the year progresses, there's a notable increase in precipitation, peaking in December with 118 mm (4.6 in). The data suggests a balanced rainfall pattern from spring through early autumn, with the late summer months generally less wet, followed by a significant rise as winter approaches. Overall, September's precipitation adds a refreshing touch to the landscape, setting the stage for the colorful autumn that follows.
As September rolls into Mondorf-les-Bains, Luxembourg, the humidity levels begin to shift, settling at 83%. This slight uptick from August's 80% hints at the transitional nature of the month, as the summer warmth gradually gives way to the cooler autumn air. Throughout the year, a notable trend emerges: humidity remains consistently high in the winter months, peaking at 93% in December, while experiencing a gentle decline during the late spring to early summer, reaching a low of 81% in May. This cyclical pattern underscores the region's temperate climate, where the air remains richly saturated, creating a lush environment that is especially inviting during the bloom of late summer and early autumn.
As September unfolds in Mondorf-les-Bains, Luxembourg, residents and visitors can expect a UV Index of 6, placing this month in the high exposure category and allowing for a burn time of about 25 minutes. This slight decline from the intense summer indices indicates the changing seasons, though caution remains essential. Following the peak of September's very high indices in June and July, the UV levels now mirror those of early spring, suggesting that while the days remain warm, protective measures against UV radiation should still be a priority. For detailed insights, check out the complete information at Mondorf-les-Bains UV Index.
UV Risk Categories
In September, Mondorf-les-Bains enjoys a delightful transition as the summer days begin to wane, offering residents and visitors alike a remarkable 313 hours of sunshine. This marks a notable shift from the peak sun-soaked days of July, which boasts 410 hours, and June, with 406 hours of bright skies. Interestingly, September maintains a commendable brightness that stands out compared to the earlier months of the year, with sunlight steadily increasing from January's meager 104 hours all the way to the late summer months. As autumn approaches, the sun continues to play an essential role in the region's ambiance, even as the daylight hours start to shrink into the cooler months ahead. Enjoying the lingering warmth of September is a cherished experience, bridging the warmth of summer with the crispness of fall.
As September rolls in, Mondorf-les-Bains offers a refreshing transition into autumn with a moderate chance of sunny weather, sitting at 40%. This marks a subtle increase from the wetter summer months, where the likelihood hovered around the mid-30s. Interestingly, September's chances are more promising than those of the previous two months, indicating that while summer is winding down, there's still room for pleasant, sunlit days. This trend is complemented by an upward trajectory from April's 51%, showing that sunshine can still make a noteworthy appearance as the year progresses, paving the way for a delightful end to summer.
As summer fades into autumn, September in Mondorf-les-Bains, Luxembourg, brings a gentle transition in daylight hours, offering approximately 12 hours of sunlight. This month marks a noticeable shift as the vibrant days of June and July, with their 16 and 15 hours respectively, start to recede. Although September enjoys more sunlight than the approaching October days, which drop to 10 hours, it clearly reflects the beginning of fall's embrace. The gradual decline in daylight signals the end of the sun-drenched summer, inviting a cozy atmosphere and the rich colors of autumn to take center stage.
In September, Mondorf-les-Bains experiences a gentle transition as the summer months fade into autumn. With an average wind speed of just 2.4 m/s (5 mph), the breezes become notably calmer compared to the bustling gusts of May and April, which peak at 4.1 m/s (9 mph) and 3.3 m/s (7 mph), respectively. This downward trend in wind speeds, which began in July and continued through August, suggests tranquil days as the landscape begins to don its autumn hues. As temperatures begin to cool, the soothing whispers of September winds create a serene atmosphere, perfect for leisurely strolls along the picturesque surroundings.
Weather in Mondorf-les-Bains varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Mondorf-les-Bains, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present stark contrasts in weather conditions. In September, temperatures range from a cool 4°C (39°F) at night to a warm 32°C (89°F) during the day, with an average of 15°C (59°F). The month experiences around 61 mm (2.4 in) of precipitation over approximately 9 days and a relative humidity of 83%. Conversely, January features much colder temperatures, with lows dropping to -9°C (15°F) and an average of 2°C (36°F), peaking at 13°C (55°F). Precipitation increases slightly to 70 mm (2.8 in) over about 11 days, with humidity reaching 91%. For more details, check out Mondorf-les-Bains weather in January.
September and February present contrasting weather patterns. In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 32°C (89°F), with an average of 15°C (59°F). The month sees about 61 mm (2.4 in) of precipitation over 9 days, accompanied by a humidity level of 83%. In comparison, February experiences much colder conditions, with temperatures dipping to a minimum of -10°C (15°F) and peaking at 19°C (66°F), averaging just 4°C (40°F). This month is wetter, recording around 73 mm (2.9 in) of precipitation across 12 days, and a higher humidity of 90%. For more detailed information, you can check out Mondorf-les-Bains weather in February.
When comparing the weather in September and March, we can see notable differences in temperature and precipitation. September typically enjoys milder temperatures, with an average of 15°C (59°F) and a maximum reaching 32°C (89°F). In contrast, March experiences much cooler conditions, averaging around 6°C (44°F) and occasionally dipping to a minimum of -11°C (13°F).
Precipitation levels are also different; September sees about 61 mm (2.4 in) of rain over 9 days, while March averages 75 mm (3.0 in) across 14 days, indicating wetter conditions in the earlier spring month. Additionally, humidity levels are slightly higher in March at 88% compared to September's 83%. For a more detailed look at the weather in March, you can refer to Mondorf-les-Bains weather in March.
When comparing the weather in September and April, notable differences emerge. September tends to be warmer, with temperatures ranging from a chilly 4°C (39°F) at night to a higher average of 15°C (59°F) during the day, peaking at a sweltering 32°C (89°F). In contrast, April experiences cooler conditions, with temperatures dropping to a minimum of -3°C (26°F) and averaging around 10°C (50°F), culminating in a milder maximum of 27°C (80°F). Precipitation is relatively modest in both months, with September receiving 61 mm (2.4 in) across 9 days, while April sees slightly less rain at 40 mm (1.6 in) over the same number of days. Humidity levels are quite consistent, with September at 83% and April slightly higher at 84%. For those interested in exploring more details about the weather in April, you can visit Mondorf-les-Bains weather in April.
In September, the weather presents a warm tapestry with minimum temperatures around 4°C (39°F) and an average of 15°C (59°F), peaking at a maximum of 32°C (89°F). On the other hand, May experiences slightly cooler conditions, with minimum temperatures dropping to 0°C (33°F) and an average of 13°C (56°F), though it can also reach a high of 31°C (88°F). Precipitation in May is slightly higher, totaling 70 mm (2.8 in) over 12 days, compared to September's 61 mm (2.4 in) over 9 days. Humidity levels remain similar in both months, hovering around 81% in May and 83% in September. For a more detailed look at May weather, you can refer to Mondorf-les-Bains weather in May.
In comparing the weather of September to that of June, it's evident that both months experience warm temperatures and moderate humidity levels. September sees a broader temperature range, with minimums dipping to 4°C (39°F) and maximums reaching up to 32°C (89°F), resulting in an average temperature of 15°C (59°F). In contrast, June tends to be slightly warmer overall, with minimum temperatures of 7°C (44°F), averages around 18°C (65°F), and highs up to 34°C (94°F). While September receives about 61 mm (2.4 in) of precipitation over 9 days, June has a bit more with 70 mm (2.7 in) across 10 days, making it a wetter month. Interestingly, humidity remains similar between the two months, with September at 83% and June just a touch lower at 82%. For a closer look at June conditions, you can explore Mondorf-les-Bains weather in June.
In comparing the weather between September and July, we can see some notable differences. September tends to be cooler on average, with temperatures ranging from a minimum of 4°C (39°F) to a maximum of 32°C (89°F), resulting in a more moderate average temperature of 15°C (59°F). In contrast, July experiences warmer weather, with temperatures that range from a minimum of 8°C (47°F) to a maximum of 38°C (101°F) and an average of 19°C (67°F). Precipitation levels are somewhat comparable, with September receiving 61 mm (2.4 in) over 9 days and July experiencing slightly higher precipitation at 70 mm (2.8 in) over 8 days. Humidity remains similar, with September at 83% and July at 82%. For a deeper understanding of July weather in this region, you can refer to Mondorf-les-Bains weather in July.
September weather in Mondorf-les-Bains experiences a notable shift compared to August. While August boasts warmer temperatures with a minimum of 7°C and an average of 19°C, September sees cooler conditions, with temperatures dropping to a minimum of 4°C and an average of 15°C. The maximum temperature in September also decreases to 32°C, compared to August's 35°C. Despite September receiving slightly more precipitation at 61 mm over 9 days compared to August's 59 mm over 12 days, the humidity is marginally higher in September at 83%, compared to 80% in August. For a more detailed look at the weather in August, visit Mondorf-les-Bains weather in August.
September generally experiences warmer temperatures, with a minimum of 4°C (39°F) and an average high of 32°C (89°F), making it a pleasant month for outdoor activities. In contrast, October sees a significant drop, with temperatures ranging from a minimum of 1°C (34°F) to a maximum of 25°C (77°F), bringing cooler days. Additionally, October tends to be wetter, with precipitation increasing to 76 mm (3.0 in) over 12 days compared to September's 61 mm (2.4 in) over 9 days. Humidity also rises slightly in October to 89%, compared to 83% in September. For more detailed insights, check out Mondorf-les-Bains weather in October.
September and November present a striking contrast in weather patterns. In September, temperatures range from a mild 4°C (39°F) at night to a warm 32°C (89°F) during the day, with an average of 15°C (59°F). The month experiences about 61 mm (2.4 in) of precipitation over approximately 9 days, coupled with a humidity level of 83%. In contrast, November sees a significant drop in temperatures, with minimums plunging to -3°C (26°F) and averages around 6°C (43°F), peaking at a maximum of 20°C (68°F). This month also has a slightly higher precipitation total of 70 mm (2.7 in), spread over 12 days, and humidity rises to 91%. For more details on specific weather conditions, you can visit Mondorf-les-Bains weather in November.
In September, the weather is notably warmer, with temperatures ranging from a minimum of 4°C (39°F) to a maximum of 32°C (89°F) and an average of 15°C (59°F). The month sees a moderate amount of precipitation at 61 mm (2.4 in) over 9 days, accompanied by a relative humidity of 83%. In contrast, December brings a significant decrease in temperature, with lows plunging to -6°C (22°F) and a maximum of only 14°C (58°F), averaging just 4°C (40°F). This wintry month also experiences higher precipitation at 118 mm (4.6 in) over 19 days and an increase in humidity to 93%. For more detailed weather insights, you can check Mondorf-les-Bains weather in December.
As summer gracefully transitions into autumn, September in Mondorf-les-Bains presents a unique blend of warm and cool experiences. While temperatures can still reach pleasant highs, the average dips to a refreshing 15°C, providing a comfortable climate for visitors. Unlike the sweltering heat of July and August, September embraces a more moderate ambiance, coupled with an increase in humidity and occasional rainfall, with around 9 days featuring precipitation. This month offers a beautiful opportunity to witness the changing seasons in a tranquil setting. For a deeper dive into the weather patterns, be sure to check out Mondorf-les-Bains Climate.