Pourquoi Bruxelles a-t-elle fermé ses parcs et ses forêts pendant plusieurs heures ?

Brussels authorities closed parks, nature reserves and woodland across the capital on Thursday 27 August as a band of thunderstorms approached Belgium, temporarily putting green spaces off limits for several hours. Bruxelles Environnement said access to the sites it manages, including the Brussels section of the Sonian Forest, would stop at 18:00; the City of Brussels also closed its parks and cemeteries, while the Bois de la Cambre shut from 19:00. Reopening was planned progressively on Friday morning after safety inspections.

For residents, commuters and visitors—including staff working around Belgium’s federal institutions and the EU quarter—the immediate instruction was simple: do not enter closed parks and avoid walking beneath trees elsewhere in the Brussels-Capital Region. The measure concerned Brussels as a city and region, not the European institutions headquartered there, although it affected the public spaces used daily by the capital’s international population.

The Royal Meteorological Institute forecast that a storm zone would enter Belgium from the south late in the afternoon and evening. In an alert relayed by Wallonia’s authorities, the IRM warned of locally violent thunderstorms, intense rainfall over a short period, hail and strong gusts. The yellow warning ran from 17:00 on 27 August until 04:00 on 28 August, with expected rainfall totals of 20 to 40 litres per square metre over one to six hours in several places and potentially more in isolated locations.

The closures reflected the division of responsibility within Brussels. Bruxelles Environnement, the regional environment agency, manages regional parks, reserves and the Brussels portion of the Sonian Forest. The City of Brussels separately controls municipal parks, cemeteries and the Bois de la Cambre. Ixelles and Uccle were among the communes that issued their own notices: Ixelles said guarded parks would close from 18:00, while Uccle specified that municipal and regional green spaces would remain inaccessible until at least 08:00 on Friday.

Brussels residents can therefore encounter slightly different closure times depending on who manages a site. That distinction matters in a region composed of 19 communes alongside regional bodies. A notice from Bruxelles Environnement does not automatically describe every municipal park, while the City of Brussels is only one municipality within the wider Brussels-Capital Region.

The safety case is based on the unpredictability of falling branches and trees. Bruxelles Environnement says it may restrict access when gusts exceed 80 kilometres per hour or when conditions otherwise require it. Between 15 April and 15 November, when trees carry leaves and are more vulnerable to wind loading, around ten parks with particularly fragile tree heritage may be closed when gusts above 70 kilometres per hour are forecast. The IRM likewise lowers its warning thresholds during the leafy season.

Two legitimate perspectives meet in such decisions. Brussels Environment and municipal safety services favour early closure because the precise location of a damaging gust cannot be predicted and staff need daylight to inspect paths and trees. Park users and operators, including seasonal guinguettes and community organisers, experience even short closures as lost recreation or cancelled activity, particularly in neighbourhoods where public green space functions as a shared garden. No Brussels authority identified an alternative that would provide the same protection while keeping wooded sites open during the warning.

The broader lesson is less about one evening’s weather than about how a dense, administratively fragmented city manages increasingly exposed urban woodland. Bruxelles Environnement links tree vulnerability partly to repeated drought, heat and extreme weather associated with climate change, although no authority attributed this particular storm directly to climate change. Safe.brussels recorded seven storm or high-wind access-restriction notices for regional parks in 2024, showing that temporary closures are an established precaution rather than an exceptional emergency power.

Officials planned inspections, cleaning and any necessary securing work before reopening. The unresolved questions were whether individual sites sustained damage and whether every park reopened at the same time; the notices reviewed did not provide a consolidated post-event assessment. Future warnings should again be checked site by site through Bruxelles Environnement and the relevant commune, with 1722 used for non-life-threatening storm damage and 112 reserved for emergencies involving immediate danger.