The Istrian peninsula was one of the few regions that German authorities had allowed their citizens to freely travel to and from. But on Thursday, Istria County was placed on the list of regions with a high risk of infection with the coronavirus.
And with the addition of Bjelovar-Bilogora County, the whole of Croatia is on the so-called red list.
The decision comes into force on Saturday, April 3 and means that anyone entering Germany from Croatia must present a negative coronavirus test within 48 hours of entering and stay in quarantine for ten days. It will be possible to break self-isolation after five days with a new negative test.
Some 15,000 tourists are expected in Istria County alone over the holiday long weekend.
The head of the Istria tourist board, Denis Ivošević, believes the move will not impact those German citizens who have already arrived in Istria for their pre-booked holidays.
Epidemiologists believe Istria will once again be categorized as safe in one month's time.
Changes to cross-border travel came into effect as of April 1, in the lead up to the holiday long weekend. Croatia is allowing entry to those with a negative EU-approved quick antigen test. Those who have proof of vaccination or who have recovered from Covid-19 can also enter providing the documentation is no more than six months old.