In the agreement with the Swedish Transport Administration, it is stated that Vytåg has the right to suspend train traffic north of Boden for 24 hours if the temperature is colder than -30 degrees.
But nothing regulates how the company can stop the traffic to the south.
Despite that, trains are put on the assembly line.
In total, there are eight departures during the weekend, affecting approximately 1,000 passengers.
Will evaluate Vytåg
The Swedish Transport Administration will evaluate whether Vytåg is right to cancel the service due to the cold, as the general forecast is -20-25 degrees this weekend.
"Ultimately, there could be a fine for the Norwegian Railways if we do not consider them to be complying with the agreement," says Peter Jonsson, communicator at the Swedish Transport Administration.
- We are not canceling the service because of an agreement, but for safety reasons, says Roger Norman, traffic manager at Vytåg.
Divided opinions about the weather forecast
The general forecast for the next 24 hours is -20-25 degrees in northern Sweden.
But Vytåg writes on its website that, according to SMHI, "very difficult weather is expected in Norrland".
But the meteorologists that SVT spoke to say otherwise - see SMHI's version in the video.
In addition to the night trains, several departures with Norrtåg, which is run by Vy, have been canceled during Friday in the northern parts of the country.