September Weather in Liege, Belgium

Last updated: August 21, 2025

September in Liège, Belgium showcases a diverse climate with temperatures ranging from a comfortable 15°C (60°F) to an impressive high of 34°C (93°F). Early fall brings the potential for cooler evenings, as lows can dip to 3°C (37°F). While the month can be relatively dry, expect about 65 mm (2.5 in) of precipitation spread over 10 days, resulting in a humidity level of 81% that adds a touch of freshness to the air. Whether you prefer warm sunny days or crisp autumn evenings, September in Liège offers a captivating blend of seasonal transitions.

September Temperature in Liege

In September, Liege experiences a delightful transition as summer fades into autumn. Temperatures begin to cool, with minimums around 3°C (37°F) and average highs reaching a comfortable 15°C (60°F). While the maximum temperature can still reach an impressive 34°C (93°F), indicating that vestiges of summer linger in the air, the overall trend signals a gentle decline from the sweltering heat of July and August. This shift brings a refreshing balance, making September an ideal time to explore the rich cultural tapestry of Liege amidst pleasant weather. As the month progresses, you can expect cooler evenings, perfect for enjoying the cozy ambiance of local cafes and parks.

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

The chart illustrates September temperature patterns in Liege, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Liege, 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).
JanFebMarAprMayJunJulAugSepOctNovDec384145505665666659534441
Data source: Temperature data for Liege 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 Liege

In September, Liege, Belgium experiences a relatively mild amount of precipitation, with 65 mm (2.5 in) falling across 10 days. This marks a decrease compared to the preceding months of July and August, which both saw over 80 mm and 84 mm respectively. However, the rainfall is not entirely absent; September's totals reflect a transitional phase as summer gives way to fall. Notably, this month tends to deliver a comfortable blend of dry spells and light showers, providing an ideal backdrop for outdoor activities before the wetter, chillier days of October, which often bring an increase in both precipitation and frequency of rain days.

September Precipitation Trends in Liege

The chart displays monthly precipitation patterns in Liege, 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 Liege, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec7176803965888284658758106
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Liege

As September rolls into Liege, Belgium, the humidity experiences a slight uptick to 81%, contrasting with the drier summer months that reached their lowest at 71% in August. This increase signifies a transition as the city prepares for the cooler autumn months, with humidity levels beginning to rise again toward the winter averages, which hover around the high 80s and low 90s. The gradual climb from the summer's comfortable levels to September's more substantial humidity reflects the shifting seasons, hinting at the damp chill that autumn brings. It's a reminder of the cyclical nature of weather in Liege, where humidity plays a crucial role in the overall climate experience.

September Average Humidity in Liege

This chart illustrates the average monthly humidity levels in Liege, 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 Liege is approximately {2}%, offering insight into how humid the weather typically is during this month.
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 Liege

September in Liege, Belgium, marks a transition from the intense summer sun to the more moderate autumn rays. With a UV Index of 5, the exposure category is classified as moderate, allowing for around 30 minutes of safe sunlight before risk of skin damage increases. This month showcases a slight decline from the high levels experienced in July and August, where the UV Index reached 8, indicating very high levels of solar radiation. As the days grow shorter and cooler, it's a perfect time to enjoy the outdoors while still being mindful of UV exposure. For more details on UV levels throughout the year, check out the Liege UV Index.

Maximum UV Index Levels in Liege for September

The chart shows the monthly maximum UV Index (UVI) for Liege 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 Liege typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124578875421
Data source: Liege 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 Liege

In September, Liege, Belgium, basks in a generous 318 hours of sunshine, marking a joyful prelude to the autumn months. This follows a vibrant summer with July peaking at 407 hours, showcasing the city's sunniest period. As the summer heat retreats, September's light remains abundant, transitioning gracefully from the high summer sun of previous months to the more balanced days of fall. Compared to the early spring months where light begins to emerge, seeing an increase from 270 hours in March to nearly 400 hours in May, the steady yet gradual decline into autumn is evident. Overall, September’s sunshine acts as a gentle reminder of the beauty in seasonal change, making it a cherished time for both locals and visitors to enjoy the warm remnants of summer before embracing the cozy hues of fall.

Monthly Sunshine Duration in Liege: September Highlighted

The September sunshine duration represents the total number of hours Liege 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.
JanFebMarAprMayJunJulAugSepOctNovDec120h204h270h342h395h395h407h380h318h241h190h134h
Data source: Liege September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Liege During September

In Liege, Belgium, September brings a moderate chance of sunny weather, with around 37% likelihood of sunshine gracing the city. This is a notable increase from the previous months of summer, where the chances hovered between 30% and 33%, suggesting that as summer transitions to autumn, residents can still enjoy glimpses of sunny days. While not as promising as the peak spring months like April, at 45%, September offers a pleasant compromise, hinting at a comfortable early autumn before the chill of October sets in, where the likelihood drops to 30%. Thus, if you’re planning to embrace the outdoors in September, you may still catch some of the last sunny days before winter approaches.

Percentage of Sunny Days in September in Liege

The chart illustrates the percentage of sunny days in Liege 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 Liege experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec9%32%39%45%31%32%33%30%37%30%26%15%
Data source: Liege September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Liege in September

In Liege, Belgium, the progression of daylight duration throughout the year reveals a captivating rhythm of the seasons. After a gradual lengthening from just 8 hours in January, daylight steadily increases, peaking at a vibrant 16 hours in June. The summer months usher in a golden glow, with July and August offering 15 and 14 hours respectively, before a gentle decline begins. As September arrives, daylight tapers to 12 hours, signaling the transition towards autumn. October continues this trend, bringing 10 hours of light, while the short days of winter re-emerge, with daylight dipping back to 8 hours by November and December. This natural ebb and flow of sunlight not only marks the changing seasons but also influences the daily rhythm and lifestyle of the city’s residents.

Average Daylight Hours in Liege for September

The chart illustrates the variation in daylight duration in Liege throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 29m10h 1m11h 55m13h 51m15h 32m16h 25m15h 57m14h 26m12h 34m10h 38m8h 55m8h
Data source: Liege daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Liege

In September, Liege, Belgium, experiences a gentle breeze, with an average wind speed of just 2.8 m/s (6 mph), marking a notable dip from the summer months. This slight decrease follows a peak in the wind speeds of 4.3 m/s (10 mph) recorded in both May and October. As the summer warmth gives way to the coolness of autumn, the calmer winds in September also highlight a trend of generally lower wind speeds during this transitional period. Following the summer's moderate gales, the winds in Liege provide a serene backdrop to the city's vibrant early autumn atmosphere, as residents and visitors alike enjoy the shift toward cooler days and picturesque fall scenery.

Average September Wind Speed in Liege

The chart displays monthly wind speed patterns in Liege, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.34.43.93.14.32.73.33.32.8 m/s4.33.34.1
Data source: Liege September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Liege Compares to Other Months

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

September and January showcase contrasting weather patterns. In September, temperatures can vary significantly, with a minimum of 3°C (37°F) and a maximum of 34°C (93°F), resulting in an average of 15°C (60°F). The month typically experiences 65 mm (2.5 in) of precipitation over about 10 days, coupled with a humidity level of 81%.

In contrast, January is much colder, with temperatures ranging from a minimum of -8°C (18°F) to a maximum of 13°C (57°F), averaging around 3°C (38°F). This month sees slightly higher precipitation at 71 mm (2.8 in) over 13 days, and the humidity rises to 91%. For a more detailed look at the weather in January, check out Liege weather in January.

September and February present contrasting weather patterns. In September, temperatures can range from a chilly 3°C (37°F) at night to a warm 34°C (93°F) during the day, with an average of 15°C (60°F). The month sees about 65 mm (2.5 in) of precipitation over approximately 10 days, accompanied by a humidity level of 81%. Conversely, February is much cooler, with temperatures dipping as low as -9°C (16°F) and reaching a maximum of 20°C (69°F), averaging around 5°C (41°F). Precipitation in February increases slightly to 76 mm (3.0 in) across 12 days, while humidity is higher at 90%. For more details on February weather conditions, check out Liege weather in February.

When comparing the weather in September and March, notable differences emerge in both temperature and precipitation. September boasts a wider temperature range, with minimums around 3°C (37°F) and maximums peaking at a warm 34°C (93°F), yielding an average of 15°C (60°F). In contrast, March experiences much cooler temperatures, with lows reaching -9°C (16°F) and highs of 23°C (74°F), culminating in an average of just 7°C (45°F). Additionally, March sees slightly higher precipitation levels at 80 mm (3.1 in) over approximately 15 days, compared to September's 65 mm (2.5 in) across 10 days. The humidity also remains elevated in both months, with March at 87% and September at 81%. For more detailed insights on March weather, you can check Liege weather in March.

When comparing the weather in September and April, notable differences emerge. September tends to be warmer, with average temperatures reaching 15°C (60°F) and highs soaring to 34°C (93°F), while April's average temperature is cooler at 10°C (50°F) and a maximum of 28°C (82°F). Precipitation is more prevalent in September, with 65 mm (2.5 in) falling over 10 days, compared to April's 39 mm (1.5 in) over 8 days. Both months experience high humidity, but September's 81% is slightly lower than April's 84%. For more detailed information on April weather, you can visit Liege weather in April.

In September, temperatures range more widely than in May, with minimums around 3°C (37°F) and maximums reaching up to 34°C (93°F). In contrast, May sees a cooler minimum temperature of 0°C (33°F) and a lower maximum of 31°C (89°F), contributing to an overall average temperature of 14°C (57°F). Both months experience similar levels of precipitation at 65 mm (2.5 in), but September has slightly fewer rainy days, averaging around 10 compared to May’s 13 days of rain. Humidity is higher in September at 81%, while May has a slightly more comfortable level at 77%. For a deeper look into the weather conditions during this time, check out Liege weather in May.

September weather offers a wider temperature range compared to June, with minimum temperatures dipping to 3°C (37°F) and maximums reaching up to 34°C (93°F). The average temperature in September is 15°C (60°F), making it slightly cooler than June, which has an average of 18°C (65°F) and minimum temperatures starting at 7°C (45°F). Additionally, September sees slightly less precipitation at 65 mm (2.5 in) over about 10 days, while June experiences 88 mm (3.5 in) with rain on 12 days. Notably, September also has higher humidity levels at 81% compared to 74% in June. For a more detailed look at June weather in Liege, you can visit Liege weather in June.

When comparing the weather in September to July, noticeable differences emerge. September experiences a broader temperature range, with minimums dropping to 3°C (37°F) and maximums reaching 34°C (93°F), giving it an average temperature of 15°C (60°F). In contrast, July tends to be warmer, with minimum temperatures at 8°C (46°F) and maximums soaring up to 40°C (104°F), averaging 19°C (66°F). Additionally, September sees around 65 mm (2.5 in) of precipitation over approximately 10 days, while July has slightly more precipitation at 82 mm (3.2 in) over 11 days, reflecting the overall humidity levels of 81% in September compared to 72% in July. For more detailed insights, check out Liege weather in July.

In comparing the weather of September and August, September tends to be slightly cooler, with temperatures ranging from a minimum of 3°C (37°F) to a maximum of 34°C (93°F), averaging at 15°C (60°F). Conversely, August experiences higher temperatures, with a minimum of 7°C (44°F) and a maximum of 36°C (97°F), averaging 19°C (66°F). Precipitation is also more frequent in August, with 84 mm (3.3 in) over 15 days compared to September’s 65 mm (2.5 in) across 10 days. Interestingly, September has a higher humidity level at 81%, compared to August's 71%. For more detailed information about August weather, you can visit Liege weather in August.

In September, the weather is notably warmer, with average temperatures ranging from a minimum of 3°C (37°F) to a maximum of 34°C (93°F). This month sees an average temperature of 15°C (60°F) and experiences about 65 mm (2.5 inches) of precipitation over approximately 10 days, with humidity levels around 81%.

In contrast, October brings a noticeable drop in temperatures, with an average ranging from a minimum of 1°C (34°F) to a maximum of 25°C (78°F) and an overall average of 12°C (54°F). Precipitation increases to 87 mm (3.4 inches) over about 13 days, and humidity rises slightly to 88%. For more detailed insights about the weather during this month, check out Liege weather in October.

September and November weather exhibit significant contrasts. In September, temperatures range from a brisk 3°C (37°F) to a warm 34°C (93°F), with an average of 15°C (60°F), while November sees much cooler conditions, with minima dropping to -4°C (25°F) and an average of only 7°C (45°F). Precipitation levels are fairly similar, with September receiving 65 mm (2.5 in) over about 10 days compared to November's 58 mm (2.3 in) across 11 days. Humidity levels also rise as the seasons change, reaching 91% in November compared to 81% in September. For a detailed look at November weather in Liege, check out Liege weather in November.

In September, the weather tends to be warm, with temperatures ranging from a minimum of 3°C (37°F) to a maximum of 34°C (93°F), and an average of 15°C (60°F). The month sees a fair amount of precipitation, totaling 65 mm (2.5 in) over approximately 10 days, accompanied by a humidity level of 81%. In contrast, December brings a significant drop in temperatures, with a minimum of -5°C (23°F) and a maximum of 15°C (59°F), averaging around 5°C (41°F). This month is also characterized by increased precipitation, totaling 106 mm (4.2 in) over about 19 days, and an even higher humidity level of 92%. For more specific details, you can check Liege weather in December.

Compare Liege's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Liege

As summer fades, September brings a notable transition in Liege's weather. With temperatures varying significantly—ranging from cool mornings to pleasantly warm afternoons—this month offers a refreshing change compared to the heat of July and August. While average humidity remains high at 81%, the increased chances of rain, with about 10 days of precipitation, signal the onset of autumn. Those curious about how September compares to other seasons will find valuable insights in the detailed analysis available at Liege Climate. Embrace the crisp air and changing leaves, as September unfolds a unique charm in Liege’s atmosphere.