Credit: Pixabay

On Monday 17 August 2026, Luxembourg's Interministerial Assessment Unit reported that smoke from the High Fens wildfire in Belgium had pushed PM10 fine particle concentrations above the alert threshold in Luxembourg, prompting authorities to maintain their precautionary recommendations.

The unit met on Monday morning to assess the latest developments. Authorities had already recorded PM10 concentrations above the daily information threshold abroad on Saturday 15 August 2026, while levels in Luxembourg remained below the threshold at the time. However, concentrations increased during Sunday 16 August 2026 evening and have now exceeded the daily threshold in Luxembourg.

Smoke and a smell of burning may still be noticeable locally in several parts of the country, while the wildfire is also temporarily affecting air quality.

According to the authorities, concentrations are expected to gradually decrease from Tuesday 18 August 2026, although levels could still locally exceed the daily threshold of 50 µg/m³.

Following elevated levels over the weekend and at the beginning of this week, authorities expect the situation to gradually improve over the coming days, although high concentrations may still occur locally.

Weather forecasts also point towards a gradual improvement in the transport of smoke and fine particles towards Luxembourg. Winds are forecast to shift significantly towards the north-west and west from Tuesday morning, before turning west to south-west, with these conditions expected to remain in place until at least Thursday 20 August 2026.

The authorities said this change should help disperse the smoke and gradually reduce its impact on Luxembourg. However, residents may still notice a smell of burning or traces of smoke locally over the coming days.

Luxembourg authorities continue to monitor the situation in coordination with their Belgian counterparts and the relevant services. As a precaution, the recommendations issued on Sunday remain in place for people who notice smoke or are affected by the smell. Residents are advised to:

  • close doors and windows;

  • limit exposure to smoke as much as possible;

  • avoid prolonged physical activity outdoors when smoke or odours are significant;

  • where applicable, limit professional activities requiring significant physical effort when smoke or odours are significant;

  • temporarily switch off ventilation systems that bring in outside air where appropriate;

  • pay particular attention to vulnerable people, including babies and young children, elderly people, pregnant women and people with respiratory or cardiovascular conditions;

  • follow information and recommendations issued by the Luxembourg authorities through official channels.

The authorities also advised residents that people should drink regularly and avoid allowing their homes to overheat, while rooms should be ventilated when outdoor conditions improve.

Authorities recommended increased caution for vulnerable people, who may be more sensitive to the effects of smoke and fine particles. Anyone experiencing symptoms or respiratory problems should contact their doctor.

To help improve air quality, the authorities also encouraged residents to:

  • use public transport where possible;

  • carpool;

  • avoid using open fireplaces.

The public can follow the latest hourly PM10 and PM2.5 concentrations measured in Luxembourg online. The Meng Loft app provides values covering a 24-hour period.