Rain showers blanketed much of central and eastern Sweden on Thursday, with skies in the west generally free from wet weather, while conditions remained mixed in the north.
Shortly before 4pm on Thursday, congestion was also starting to plague the motorways carrying travelers out of Stockholm.
“We can see backups starting on the E4 toward Södertälje near Bredäng, as well as well as on the northbound Essingeleden,” said Eva Nylander Andersson from Trafik Stockholm to the Dagens Nyheter (DN) newspaper.
She added that conditions were expected to worsen throughout the evening.
“There is definitely going to be heavy traffic. Especially on the southbound E4 and on the E18 heading north toward Norrtälje,” said Nylander Andersson.
Congestion was also reported on roads to several popular weekend destinations such as Dalarna in central Sweden, the west coast, and the island of Öland off southeastern Sweden.
According to the Swedish Road Administration (Vägverket) roads with the highest risk for traffic delays include the E22 motorway, both northbound and southbound to Kalmar and the Öland Bridge as well as northbound E6 out of Gothenburg.
Drivers should also expect delays when traveling on Route 50 between Örebro and Ludvika in central Sweden, and Route 70 toward Dalarna and Lake Siljan.
According to Swedish meteorological agency SMHI, the low pressure system moving across the southern half of the country will likely stall over Svealand in central Sweden on Midsummer's Eve, bringing scattered showers to the region.
There is an elevated risk for rain as well as scattered thunderstorms across much of central Sweden on Friday, from western Götaland in the southwest to the southern parts of Norrland in the north.
Only in Sweden's far north can weekend revelers expect to have a clear and dry start to the Midusmmer weekend, according to SMHI.
Rain is expected to persist in many parts of the country on Saturday, Midsummer Day, with temperatures ranging from 14 to 18 degrees Celsius in the south to 10 to 15 degrees in the north.
By Sunday, the rain is expected to dissipate, being replaced by scattered cloud cover, with temperatures warming somewhat to between 15 and 18 degrees across most of the country.