September Weather in Zaventem, Belgium

Last updated: August 21, 2025

September in Zaventem, Belgium presents a captivating weather tapestry, showcasing a maximum temperature peaking at 33°C (93°F), offering unexpected warmth for the season. The average temperature hovers around a comfortable 16°C (60°F), while colder nights can dip to a brisk 4°C (39°F). Throughout the month, the region experiences a total precipitation of 50 mm (2.0 in) over 9 rain-soaked days, contributing to the vibrant autumnal atmosphere. With an average humidity of 82%, Zaventem balances warmth and moisture, making it a unique time for both locals and visitors to enjoy the transitional beauty of early fall.

September Temperature in Zaventem

September in Zaventem, Belgium marks a delightful transition from summer's heat to autumn's crispness. With average temperatures reaching 16°C (60°F), this month offers a perfect balance, where warm days can still flirt with a maximum of 33°C (93°F) while the nights cool off to a comfortable minimum of 4°C (39°F). As the month progresses, the days gradually shorten, hinting at the nearing chill of October. September's climate invites outdoor enthusiasts to relish the last warm days before the seasonal shift, making it an ideal time for strolls, picnics, and appreciating the changing foliage. The warmth of late summer melds with the fresh air of early autumn, creating a picturesque setting that highlights the beauty of this transitional month.

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

The chart illustrates September temperature patterns in Zaventem, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Zaventem, 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).
JanFebMarAprMayJunJulAugSepOctNovDec404245505765666660554542
Data source: Temperature data for Zaventem 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 Zaventem

September in Zaventem, Belgium, typically marks a transition as summer fades and autumn approaches. This month sees an average precipitation amount of 50 mm (2.0 in), making it one of the drier periods compared to its wetter preceding months, August and October. With just 9 rainy days, September offers a respite from the frequently damp weather, allowing residents and visitors to enjoy the early signs of fall without frequent interruptions. As the rainfall starts to decrease, it complements the cooler temperatures that herald the onset of the new season, creating a perfect backdrop for autumn activities and scenic landscapes. Overall, September strikes a balance between the lingering warmth of summer and the chill of approaching autumn, with its moderate rainfall adding a touch of freshness to the air.

September Precipitation Trends in Zaventem

The chart displays monthly precipitation patterns in Zaventem, 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 Zaventem, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec626768355764717450775388
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Zaventem

As autumn approaches, September in Zaventem, Belgium sees a notable shift in humidity levels, stabilizing at around 82%. This marks a slight increase from the summer's lowest point of 76% in August, suggesting that the air is starting to retain more moisture as the season transitions. Throughout the year, Zaventem experiences its highest humidity in the winter months, peaking at 91% in January, while the late summer and early autumn months exhibit a gradual rise from the drier season. With the humidity expected to climb further into the fall, residents can anticipate a moister atmosphere as October brings its own increase to 89%, indicating a return to the characteristic dampness of the Belgian climate.

September Average Humidity in Zaventem

This chart illustrates the average monthly humidity levels in Zaventem, 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 Zaventem is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec91%89%87%85%82%82%80%76%82%89%92%92%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Zaventem

In September, Zaventem experiences a moderate UV Index of 5, signaling a transition from the intense summer months. With a burn time of 30 minutes, it's advisable to be mindful of sun exposure, particularly during midday hours. This drop in UV levels from the peak of 8 in July and 8 in June indicates a gradual easing of the summer sun's intensity, making it a great time for outdoor activities while still practicing sun safety. As the season shifts, you'll find that while the risk of sunburn decreases, it’s still essential to stay protected. For more detailed information, visit Zaventem UV Index.

Maximum UV Index Levels in Zaventem for September

The chart shows the monthly maximum UV Index (UVI) for Zaventem 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 Zaventem typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec124578875321
Data source: Zaventem 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 Zaventem

As September rolls in Zaventem, Belgium, the city basks in a generous 320 hours of sunshine, marking a gentle decline from the vibrant 411 hours of July. This month strikes a balance as summer winds down, yielding to autumn's embrace without losing its warm glow — the sun still shines brightly, offering a respite before the more muted days of October and November, which see a further drop to 241 and 191 hours respectively. Interestingly, September's hours reflect a notable shift compared to the high summer months, yet they remain significantly higher than the bleak winter months, emphasizing the transitional beauty of early fall in this charming corner of Belgium.

Monthly Sunshine Duration in Zaventem: September Highlighted

The September sunshine duration represents the total number of hours Zaventem 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.
JanFebMarAprMayJunJulAugSepOctNovDec120h203h272h348h397h400h411h383h320h241h191h143h
Data source: Zaventem September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Zaventem During September

In Zaventem, Belgium, the likelihood of sunny weather in September hovers around 34%, mirroring the trends observed in the summer months. As the year progresses towards autumn, September maintains a relatively stable chance of sunshine, paralleling the June to August average. While this percentage indicates that sunny days aren't guaranteed, it provides a pleasant opportunity for outdoor activities before the onset of cooler weather. Interestingly, as the temperature begins to dip in October, the chance of sun lessens to 31%, suggesting that those seeking warmth and brightness should take advantage of September's decent weather while they can.

Percentage of Sunny Days in September in Zaventem

The chart illustrates the percentage of sunny days in Zaventem 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 Zaventem experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec11%31%39%47%33%34%34%31%34%31%24%17%
Data source: Zaventem September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Zaventem in September

September in Zaventem, Belgium, marks the transition from the long, sun-drenched days of summer to the shorter daylight hours of autumn. With 12 hours of daylight, the sunlit days begin to wane, a gentle decline from the vibrant 14 hours in August. This shift reflects a broader trend throughout the year, where daylight gradually increases from a mere 8 hours in January to a peak of 16 hours in June before tapering off again. As September unfolds, the nights grow longer and the air crisper, inviting residents to savor the final moments of summer’s glow while preparing for the cozy embrace of fall.

Average Daylight Hours in Zaventem for September

The chart illustrates the variation in daylight duration in Zaventem throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec8h 27m10h11h 55m13h 52m15h 34m16h 27m15h 59m14h 27m12h 34m10h 38m8h 53m7h 58m
Data source: Zaventem daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Zaventem

In September, Zaventem experiences a gentle decline in average wind speed, averaging just 2.9 m/s (6 mph). This marks a noticeable shift from the breezy summer months, where wind speeds hovered around 3.2 m/s (7 mph) in both July and August. As the transition to autumn begins, the air feels softer, reflecting the seasonal change. Notably, this month has the lowest wind speed recorded for the year, hinting at a tranquil atmosphere that invites outdoor activities. Looking ahead, the wind picks up again in October, signaling the impending transition into the more dynamic winds of late fall. The calmness of September not only provides a serene backdrop but also offers a chance to savor the fleeting warmth before winter sets in.

Average September Wind Speed in Zaventem

The chart displays monthly wind speed patterns in Zaventem, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4.24.33.83.34.12.73.23.22.9 m/s4.13.23.9
Data source: Zaventem September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Zaventem Compares to Other Months

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

September and January present contrasting weather patterns. In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 33°C (93°F), with an average of 16°C (60°F). The month experiences about 50 mm (2.0 in) of precipitation over 9 days, accompanied by a relatively high humidity of 82%. In stark contrast, January is much colder, featuring temperatures that drop to a minimum of -6°C (21°F) and peak at 14°C (58°F), averaging around 4°C (40°F). This month is slightly wetter, with 62 mm (2.4 in) of precipitation across 11 days and a higher humidity of 91%. For more details, you can check the link: Zaventem weather in January.

September and February exhibit stark differences in weather conditions. September typically experiences milder temperatures, with a minimum of 4°C (39°F) and a maximum of 33°C (93°F), leading to an average of 16°C (60°F). This month sees around 50 mm (2.0 in) of precipitation over 9 days, with humidity at 82%. In contrast, February is much colder, featuring a minimum temperature of -9°C (16°F) and a maximum of 19°C (66°F), resulting in an average of 6°C (42°F). Precipitation increases slightly to 67 mm (2.6 in) across 12 days, with a higher humidity level of 89%. For a more detailed look at February weather, visit Zaventem weather in February.

September and March exhibit distinctly different weather patterns. September typically offers warmer temperatures, with a range from a chilly 4°C (39°F) to a high of 33°C (93°F), an average of 16°C (60°F), and relatively lower humidity at 82%. In contrast, March is noticeably cooler, featuring temperatures that vary from a minimum of -7°C (19°F) to a maximum of 23°C (74°F), with an average of 7°C (46°F) and higher humidity levels at 87%. Additionally, March sees more precipitation, totaling 68 mm (2.7 in) over 13 days, compared to September's 50 mm (2.0 in) over 9 days. For more detailed insights, you can visit Zaventem weather in March.

When comparing the weather in September to that of April, it's evident that September offers a warmer range of temperatures, with a minimum of 4°C and an average high of 33°C, while April experiences cooler temperatures, starting from a minimum of -4°C and peaking at 28°C. However, April has a slightly lower average temperature, with an average of 10°C compared to September's 16°C. In terms of precipitation, September receives more rainfall (50 mm over 9 days) compared to April's 35 mm over 7 days, yet April has a marginally higher humidity level at 85% versus September's 82%. For more details on April weather, you can visit Zaventem weather in April.

When comparing the weather in September and May, we see notable differences. September experiences slightly warmer temperatures, with a minimum of 4°C and an average of 16°C, while May has a lower minimum of 1°C and an average of 14°C. Both months can reach similar maximum temperatures, with September peaking at 33°C and May at 32°C. Precipitation is slightly higher in May, totaling 57 mm over 12 days compared to September's 50 mm over 9 days. Interestingly, both months maintain a humidity level of 82%, creating a consistently moist atmosphere. For more detailed information about May weather, you can visit Zaventem weather in May.

When comparing the weather in September and June, both months experience similar maximum temperatures, reaching up to 33°C (93°F) in September and 33°C (92°F) in June. However, September generally has cooler minimum temperatures, ranging from 4°C (39°F) to 16°C (60°F), while June starts at a higher minimum of 8°C (46°F) to 18°C (65°F). Additionally, June sees slightly more precipitation, with 64 mm (2.5 in) compared to September's 50 mm (2.0 in), despite both months experiencing rain on about 9 days. Moreover, humidity remains constant at 82% for both months, contributing to a moist atmosphere. For more detailed information about June weather, you can check Zaventem weather in June.

When comparing the weather in September and July, notable differences emerge in temperature and precipitation patterns. September typically experiences a wider temperature range, with minimums dropping to 4°C (39°F) and maximums reaching up to 33°C (93°F), averaging around 16°C (60°F). In contrast, July has milder minimums of 8°C (47°F) and peaks at a sweltering 39°C (103°F), averaging 19°C (67°F). Precipitation is more pronounced in July, totaling 71 mm (2.8 in) over 10 days, compared to September's 50 mm (2.0 in) over 9 days. Both months maintain a relatively high humidity level, with September at 82% and July slightly lower at 80%. For more specific insights, check out Zaventem weather in July.

In comparing the weather between August and September, September tends to be slightly cooler overall, with average temperatures ranging from a minimum of 4°C (39°F) to a maximum of 33°C (93°F), compared to August's milder range of 8°C (47°F) to 36°C (96°F). Additionally, September experiences more precipitation days, totaling 9 days with 50 mm (2.0 in) of rain, while August has 13 days of rain and a higher total of 74 mm (2.9 in). Humidity levels are also higher in September at 82%, compared to 76% in August, contributing to a more humid feel as the month progresses. For more details, take a look at Zaventem weather in August.

In September, temperatures ranged from a minimum of 4°C (39°F) to a maximum of 33°C (93°F), with an average of 16°C (60°F). The month experienced 50 mm (2.0 in) of precipitation over nine days, and humidity levels hovered around 82%. In contrast, October sees cooler temperatures, with a minimum of 2°C (35°F), an average of 13°C (55°F), and a maximum of 26°C (79°F). Precipitation also increases to 77 mm (3.0 in) over twelve days, accompanied by higher humidity at 89%. For more detailed weather information, you can visit Zaventem weather in October.

September and November offer distinct weather experiences, reflecting the transition from late summer to early winter. In September, temperatures range from a minimum of 4°C (39°F) to a maximum of 33°C (93°F), with an average of 16°C (60°F). The month witnesses about 50 mm (2.0 in) of precipitation over 9 days, coupled with a humidity level of 82%. In contrast, November sees much cooler conditions, with temperatures ranging from -3°C (28°F) to a maximum of 19°C (66°F) and an average of 7°C (46°F). The month receives slightly more rainfall at 53 mm (2.1 in) over 10 days and experiences higher humidity at 92%. For more detailed insights into November weather, you can refer to Zaventem weather in November.

In September, the weather is significantly warmer, with an average temperature of 16°C (60°F) and maximum highs reaching up to 33°C (93°F). However, it also features high humidity at 82% and some precipitation over approximately 9 days, totaling 50 mm (2.0 in). In contrast, December brings a much colder climate, as temperatures range from a minimum of -5°C (23°F) to a maximum of 15°C (60°F), with an average of 6°C (42°F). The month experiences more frequent rainfall, with precipitation on 16 days amounting to 88 mm (3.5 in) and humidity levels rising to 92%. For a detailed look at December’s weather, refer to Zaventem weather in December.

Compare Zaventem's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Zaventem

As September rolls in, Zaventem experiences a delightful transition marked by mild temperatures and a noticeable drop in humidity compared to the sweltering summer months. The average temperature settles around a comfortable 16°C, while the min-max range stretches from refreshing coolness to pleasant warmth. Although precipitation becomes a little more frequent—with about 9 days of rain—this only enhances the charm of early autumn. With a total of 50 mm of rainfall, the lush surroundings are revitalized after the summer heat. For those wanting to learn more about the unique climate features of this enchanting area, visit Zaventem Climate.