Rubber boots tend to be the most important piece of clothing at the Roskilde Festival, and judging by the latest weather forecast, this year will be no exception.

There's a chance of rain on every single day of the festival from Sunday June 29 to Sunday July 6, except for Thursday July 3 when the music starts to play.

While it may still be too early to predict with certainty that far ahead (for example, a deluge is specifically predicted for the first six hours of Friday July 4), the opening weekend will definitely be wet.

"There's some uncertainty in the longer run, but don't expect sunshine and high pressure," Klaus Larsen of national weather institute DMI told Politiken.

Queuing up for a downpour
When the festival this weekend opens for the thousands of festival-goers waiting in line at the entrance a day in advance, it is going to rain. A lot.

"As it looks now, it seems to be a weekend with showers and rain. Quite a bit of rain, in fact," Larsen said.

The rain may already begin on Friday with up to 10 mm of rain, which may quickly turn the grassy fields into a muddy wasteland.

However, Larsen stressed that it may not be as bad if the low pressure zone heading for Denmark changes course.

Even the most optimistic festival-goers should not forget their boots.