Judge Andrea Darvas said she'll issue a ruling with reasoning after Christmas Day but before January 1. Parties in the case had been expecting a ruling Friday.
The measure is scheduled to go into effect on January 1.
Last month voters in SeaTac narrowly approved the measure, which would require a $15 minimum wage, a handful of paid sick days and other standards to around 6,000 workers at the airport and related industries, like hotels and rental car companies.
However, the legal fight over the measure is not expected to end with Darvas' ruling. An eventual appeal to the state Supreme Court could come from either side, depending on her ruling.
The challenge to the newly approved measure is being led by Alaska Airlines Group and other businesses. They say that a city initiative doesn't have power of the airport, which his operated by the Port of Seattle. That point of view is also shared by the Port of Seattle, a public entity.
Alaska Airlines Group also says that requirements the measure sets violate the law that says initiatives can't package multiple laws.
In all, $1.8 million were spent in total during the campaign season. Alaska Airlines Group donated heavily to defeat the measure, while labor groups supported the proposal.
Supporters dismissed the business group's court arguments, saying that ports don't enact social welfare laws, but rather cities do. They say increasing the minimum wage is needed to make a living in the area where wages haven't kept up with inflation and rising housing costs. A group of labor-backed demonstrators rallied outside the courthouse on Friday as well.
Washington has the nation's highest state minimum wage at $9.19 an hour. The federal minimum wage is $7.25 an hour.