The Danish Meteorological Institute (DMI) forecast for Esbjerg and surrounding areas showed a constant rainfall level of 18mm on Monday evening and Tuesday.
After being contacted by concerned citizens on Twitter, DMI confirmed that the forecast was “of course a mistake”.
“We are working hard to fix it,” wrote the agency.
Byvejr med sin egen bittersøde kommentar til sommeren '17...— DMI (@dmidk) September 10, 2017
Nå, spøg til side. Det er selvfølgelig en fejl. Vi knokler for at fikse det https://t.co/gjmcvrAvLx
DMI's duty meteorologist Henning Gisselø later told newspaper BT such high rainfall “cannot realistically occur”.
"There was a technical error, but exactly what happened, I can't say," Gisselø added.
But Danes hoping for a dry start to the week are nevertheless likely to be disappointed – the real weather forecast predicts rain and showers over much of the country on both Monday and Tuesday.
Southern Jutland is expected to see the most wet weather, with around nine millimetres in total forecast.