Last updated: August 21, 2025
September in Grimbergen, Belgium showcases a delightful transition from summer’s warmth to the crispness of autumn. With temperatures peaking at a balmy 33°C (91°F), the month offers an average temperature of 16°C (60°F), while dipping to a cool 4°C (40°F) at night. Rainfall is a common theme, with 50 mm (2.0 in) of precipitation spread over 9 days, contributing to an overall humidity level of 82%. Whether you’re exploring the scenic streets or enjoying local festivities, expect a blend of warm days and refreshing showers that define this charming month.
As summer wanes, September in Grimbergen, Belgium brings a gentle transition towards autumn, characterized by mild temperatures that invite outdoor exploration. With nighttime lows dipping to 4°C (40°F), the days can still reach a warm 33°C (91°F), blending the remnants of summer warmth with the crispness of fall. The average temperature settles at a comfortable 16°C (60°F), making this month ideal for enjoying the stunning scenery as the leaves begin to change. While still warm compared to the cooler months that follow, September signals a shift, hinting at the chilly weather ahead, yet still provides plenty of opportunities for sun-filled days and vibrant local culture.
In September, Grimbergen experiences a moderate dip in precipitation, receiving 50 mm (2.0 in) of rain over 9 days. This marks a contrast to the wetter months of August and October, which witness more significant rainfall, at 73 mm (2.9 in) and 79 mm (3.1 in) respectively. This reduction in precipitation is reflective of the transitioning seasons, as the late-summer warmth begins to wane. The nine days of rain during September suggest a gentle embrace of autumn, setting a serene tone for the month while still allowing for ample dry days. As the year progresses, it becomes evident that September serves as a bridge between the distinctly wetter summer months and the more rainfall-prone autumn ahead.
In September, Grimbergen experiences a slight uptick in humidity, reaching 82%. This marks a transition from the drier summer months of July and August, where humidity levels dipped to 80% and 76%, respectively. As autumn approaches, the shift in humidity reflects the region's characteristic seasonal rhythm, where levels begin to climb once again, echoing the higher values of spring and early fall. With humidity in September remaining consistent with May and June, residents can expect a mild yet slightly moist atmosphere, paving the way for the increased humidity that will return in October and November. The overall trend demonstrates how Grimbergen's climate is shaped by its changing seasons, each bringing its unique humidity signature.
As summer fades, September in Grimbergen marks a shift in UV exposure, bringing a moderate UV Index of 5 that calls for some cautious sun enjoyment. While this level indicates a manageable risk of harm from unprotected sun exposure, it is essential to be mindful, especially during peak hours, as the recommended burn time remains at 30 minutes. Compared to the heightened intensity of July and August, with their very high indexes of 8, September offers a gentler sun experience, though vigilance is still advised. As the days grow shorter and cooler, the gradual decline from summer’s high UV levels signifies the transition into autumn. For more details on sun safety and UV trends, visit Grimbergen UV Index.
UV Risk Categories
September in Grimbergen, Belgium, offers a delightful transition from the vibrant summer months to the cooler embrace of autumn. With 320 hours of sunshine, this month signals a gradual decline in sunlight, following a peak in July with 411 hours. The warm days of September still linger, allowing residents and visitors to savor the beauty of early fall. As the days shorten and the sun’s rays become less abundant, the dazzling display of autumn leaves begins to take center stage, reminding us of the cycle of change in this charming town. The light, while lessening compared to the bustling summer, still paints Grimbergen in a golden hue, making it a perfect time for leisurely strolls and outdoor gatherings.
In Grimbergen, Belgium, the likelihood of sunny weather in September holds steady at a 34% chance, mirroring the patterns seen in the months of June, July, and August. This consistency suggests that while summer's peak may have passed, the charming early autumn days still offer a fair amount of sunshine. Interestingly, this figure falls in line with the overall trend of increasing sunlight from the dreary depths of winter in January, which starts at only 11%, gradually climbing through spring and peaking in early summer. As September rolls in, residents can still look forward to a pleasant mix of sunny days, perfect for enjoying the transition into autumn.
As summer fades into autumn, September in Grimbergen, Belgium offers a gentle transition with approximately 12 hours of daylight. Following the sun-drenched days of June and July, which boast up to 16 hours of light, September sees a noticeable decline, yet retains a comfortable brightness for outdoor activities. This month serves as a bridge, softly receding from the vibrant, sun-filled hours of summer towards the shorter days of fall, mirroring nature's gradual shift. With daylight tapering off, it beckons locals to enjoy the waning warmth while preparing for the cozy embrace of October, where daylight dips to 10 hours.
As September rolls into Grimbergen, Belgium, the wind begins to whisper its way through the streets at an average speed of 3.0 m/s (7 mph), marking a notable dip from the breezier summer months. This gentle breeze, while relatively calm compared to the earlier season, sets the stage for the crisp autumn air that follows. Observing the trend throughout the year, we see that winds are typically strongest in the winter months, peaking in January with 4.3 m/s (10 mph) and gradually softening as summer approaches. After the slight reprieve in June, September’s languid gusts signal a transition—bridging the vibrant light of summer with the cooler embrace of October, which promises a resurgence in wind speed as temperatures drop once again. The rhythmic ebb and flow of the winds uniquely reflect the changing seasons, infusing September with a serene yet anticipatory atmosphere in Grimbergen.
Weather in Grimbergen varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Grimbergen, 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 (40°F) to a maximum of 33°C (91°F), with an average of 16°C (60°F). This month experiences around 50 mm (2.0 in) of precipitation over 9 days, accompanied by a relative humidity of 82%. In stark contrast, January witnesses much cooler temperatures, with a minimum of -6°C (21°F) and a maximum of 14°C (58°F), averaging only 4°C (40°F). Precipitation increases to 62 mm (2.4 in) spread over 12 days, and humidity rises to 91%. For more specifics on January conditions, you can visit Grimbergen weather in January.
When comparing the weather in September and February, a stark contrast emerges. September typically offers a milder climate with temperatures ranging from a minimum of 4°C (40°F) to a maximum of 33°C (91°F), averaging 16°C (60°F). This month sees about 50 mm (2.0 in) of precipitation over approximately 9 days and has a humidity level of 82%. In contrast, February is much colder, with temperatures dropping to a minimum of -12°C (11°F) and peaking at 19°C (66°F), averaging just 6°C (42°F). Precipitation levels increase slightly to 67 mm (2.6 in) over 12 days, accompanied by a higher humidity of 89%. For more detailed insights, you can explore Grimbergen weather in February.
When comparing the weather in September and March, notable differences emerge in temperature, precipitation, and humidity levels. September typically experiences milder temperatures, with an average of 16°C (60°F) and highs reaching up to 33°C (91°F). In contrast, March tends to be much cooler, averaging only 7°C (46°F) and peaking at 23°C (73°F). Precipitation is more frequent in March, with rain falling on about 14 days and totaling 69 mm (2.7 in), compared to September's 50 mm (2.0 in) over 9 days. Both months exhibit high humidity, but March has a slightly higher average at 87%, compared to September's 82%. For further detailed insights, you can explore Grimbergen weather in March.
In comparing the weather of September and April, we see notable differences in temperature and overall conditions. September boasts a wider temperature range, with minimums of 4°C (40°F) and maximums reaching up to 33°C (91°F), resulting in an average of 16°C (60°F). In contrast, April's temperatures are generally cooler, ranging from a low of -3°C (26°F) to a high of 27°C (81°F), with an average of only 10°C (51°F).
Precipitation levels are fairly similar, with September receiving about 50 mm (2.0 in) over 9 days, and April receiving a slightly lesser amount of 38 mm (1.5 in) over 8 days. Humidity is relatively high in both months, with September at 82% and April slightly higher at 85%. For more detailed information on April weather, you can check out Grimbergen weather in April.
In comparing September and May weather, both months experience relatively mild temperatures, but September tends to have higher maximum temperatures, reaching up to 33°C (91°F) compared to May's maximum of 31°C (88°F). The average temperature in September is also slightly warmer at 16°C (60°F) versus May's 14°C (57°F). However, May has cooler minimum temperatures, with a low of 1°C (35°F), compared to September's low of 4°C (40°F). Precipitation is a common feature in both months, with May receiving slightly more at 58 mm (2.3 in) over 12 days, compared to September's 50 mm (2.0 in) over 9 days. Both months maintain a consistent humidity level of 82%, making them feel quite similar in terms of muggy conditions. For more detailed information about May weather, visit Grimbergen weather in May.
September and June exhibit relatively similar weather patterns, with both months experiencing high humidity levels of 82%. However, September typically showcases a broader temperature range, with minimums dipping down to 4°C (40°F) and maximums reaching up to 33°C (91°F), while June's temperatures are slightly warmer, ranging from a minimum of 8°C (46°F) to a maximum of 32°C (91°F). Precipitation is another notable difference; September sees about 50 mm (2.0 in) of rainfall, compared to June's 63 mm (2.5 in), both spread across approximately nine days. This makes both months relatively wet, yet June tends to be a bit wetter overall. For more details about the weather in June, you can check Grimbergen weather in June.
When comparing the weather in September and July, some notable differences emerge. September experiences slightly cooler temperatures, with a minimum of 4°C (40°F) and an average of 16°C (60°F), whereas July starts off at a minimum of 8°C (47°F) and an average of 19°C (67°F). July also sees higher maximum temperatures, reaching up to 39°C (102°F), compared to September's peak of 33°C (91°F). Precipitation is more pronounced in July, with 67 mm (2.6 in) over 11 days, in contrast to September's 50 mm (2.0 in) across 9 days. Humidity levels remain relatively similar, with July at 80% and September at 82%. For more specific details about July weather, visit Grimbergen weather in July.
In comparing the weather between August and September, we see notable differences in temperatures and precipitation patterns. September boasts a broader temperature range, with minimums dropping to 4°C (40°F) and maximums reaching up to 33°C (91°F), while the average temperature cools to about 16°C (60°F). In contrast, August tends to be warmer, with minimums at 8°C (47°F) and maximums peaking at 35°C (96°F), leading to a higher average of 19°C (66°F).
Precipitation is also more pronounced in August, with a total of 73 mm (2.9 in) over 14 days, compared to September's 50 mm (2.0 in) falling on 9 days. The humidity is slightly higher in September at 82%, while August enjoys a lower humidity level at 76%. For a more detailed look at August's weather, you can check Grimbergen weather in August.
September and October present a noticeable shift in weather patterns. In September, temperatures typically range from a minimum of 4°C (40°F) to a maximum of 33°C (91°F), with an average of 16°C (60°F). The month sees about 50 mm (2.0 in) of precipitation over 9 days, accompanied by a humidity level of 82%. In contrast, October experiences cooler temperatures, with lows of 2°C (35°F) and highs reaching 25°C (78°F), averaging around 13°C (55°F). This month receives more rainfall—approximately 79 mm (3.1 in) spread over 13 days—and an increase in humidity to 89%. For a closer look at the specific conditions, visit Grimbergen weather in October.
September and November present quite contrasting weather patterns. In September, temperatures range from a mild 4°C (40°F) at night to a warm 33°C (91°F) during the day, with an average of 16°C (60°F). This month sees 50 mm (2.0 in) of precipitation over about 9 days, accompanied by high humidity of 82%. In contrast, November ushers in cooler temperatures, with nighttime lows dipping to -2°C (28°F) and daytime highs reaching only 19°C (66°F), averaging around 8°C (46°F). Precipitation increases slightly to 53 mm (2.1 in) over 11 days, and humidity rises to 92%. For more detailed insights, you can check the Grimbergen weather in November.
In September, the weather exhibits a warm and fluctuating climate, with temperatures ranging from a minimum of 4°C (40°F) to a maximum of 33°C (91°F) and an average of 16°C (60°F). Despite the pleasant warmth, September also sees about 50 mm (2.0 in) of precipitation over 9 days, and a humidity level of 82%. In contrast, December brings significantly cooler temperatures, with a minimum of -4°C (24°F) and a maximum of 15°C (59°F), averaging just 6°C (43°F). Precipitation increases in December, totaling 89 mm (3.5 in) spread across 16 days, while humidity rises slightly to 92%. For more details on the December weather, you can check out Grimbergen weather in December.
As September rolls in, Grimbergen's weather begins to transition, showcasing a unique blend of warmth and coolness that sets it apart from the summer months. With temperatures reaching up to 33°C, it's a warm farewell to summer, yet the average dips to a more refreshing 16°C, inviting residents and visitors alike to enjoy the crisp air. While there are fewer sunny days, with 9 days of precipitation totaling about 50 mm, the humidity remains high at 82%, giving the air a distinct freshness. This harmonious mix of warmth and moisture creates a beautiful autumn backdrop, making September a delightful time to explore all that Grimbergen has to offer. For a deeper understanding of the area's weather variations throughout the year, check out Grimbergen Climate.