The capital region utility company HOFOR warned residents on Monday to avoid contact with sewage water, as Denmark’s national weather institute forecast cloudbursts across large parts of the country.
According to reporting by DR, HOFOR issued a public advisory on August 31, 2026, after Danmarks Meteorologiske Institut warned of heavy rain. The utility said roads and squares in the Copenhagen area could be flooded during the downpours.
HOFOR urged people to be extra attentive when moving around the city while the rain falls. The company noted that cloudbursts can push sewage into bathing water, leaving kloakvand in harbors and at city beaches.
The advisory tells residents to avoid contact with sewage water and not to bathe in harbor baths or beaches close to the city. HOFOR said the guidance applies both during and after heavy rain, when sewers are still overloaded.
The utility also drew attention to manhole covers, which can be affected when pressure builds in the sewer network. HOFOR asked people to watch out for loose covers on flooded streets, as reported by DR.
The weather warning behind the advisory
DR Vejret reported that DMI issued a skybrud warning for large parts of Denmark on August 31. The forecast included 20 to 40 millimeters of rain with a risk of local cloudbursts.
DR Vejret described the day as summer’s last, with the unstable weather arriving as the meteorological season closes. The warning covered wide areas rather than a single region.
HOFOR is the utility company serving the capital region, and it operates the sewer network in the Copenhagen area. Its advisory was issued in direct response to the DMI warning, according to DR.
Cloudbursts in Denmark are defined by DMI as at least 15 millimeters of rain within 30 minutes. The wild weather warning system is used to alert the public before such events.
Heavy rain of this intensity can exceed the capacity of the combined sewer system in older parts of Copenhagen. In those situations, overflow is released to protect buildings and the network itself.
HOFOR’s advisory did not name specific harbor baths or beaches that should be avoided. The company framed the guidance as applying generally to harbor water and beaches near the city.
Save up to 2,800 DKK on Your Electricity Bill
FindElpriser helps you switch electricity providers quickly and easily.
Simple steps such as flood prevention in Denmark measures are frequently raised around cloudburst warnings. HOFOR’s advisory on Monday focused on public safety in streets and bathing water.
