Airlines are ditching face mask rules for the first time in two years. Here's what travelers need to know.

It looks like the mask mandate on airplanes won't be in place an extra two weeks after all.

United, American, Southwest, Delta, Alaska and other airlines late Monday said they were dropping their face mask requirement effective immediately given a federal judge's ruling in Florida and the White House response to it.

The mask mandate, announced in January 2021, had been set to expire Monday. But the Centers for Disease Control and Prevention announced last week that it would keep it in place until May 3 to allow more time to study the BA.2 omicron subvariant of the coronavirus that is responsible for the majority of cases in the country. It was the mask mandate's fifth extension despite repeated requests from airlines and other travel industry officials to ease restrictions.

The court ruling moved up the timeline, barring any appeals, so passengers boarding flights late Monday are doing so without masks for the first time in nearly two years. Airlines began requiring masks before the government did, with JetBlue Airways the first carrier to announce the move. The airline's policy was quickly matched by other carriers.

Fast forward two years, and airlines, which have been pushing for an end to the mandate, are rushing to remove the mask requirement.

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Do you have to wear masks on airplanes?

An airline-by-airline look on new face mask policies as of Monday, April 18. Policies vary by airline and are subject to change. This list will be updated as U.S. airlines update their rules.

►American Airlines: Face masks will no longer be required for customers and employees at U.S. airports and on domestic flights.

"Please note face masks may still be required based on local ordinances, or when traveling to/from certain international locations based on country requirements,'' the airline said in a statement. "In keeping with our commitment to creating a welcoming environment for everyone who travels with us, customers and team members may choose to continue to wear masks at their own discretion.''

►Delta Air Lines: Effective immediately, masks are optional for passengers inside U.S. airports and onboard aircraft. Delta travelers and employees and customers may continue wearing masks if they so choose.

"Given the unexpected nature of this announcement, please be aware that customers, airline employees and federal agency employees - such as TSA - may be receiving this information at different times,'' Delta said in a statement. "You may experience inconsistent enforcement during the next 24 hours as this news is more broadly communicated - remember to show understanding and patience with others who may not be aware enforcement is no longer required. Communications to customers and in-airport signage and announcements will be updated to share that masking is now optional - this may take a short period of time."

►United Airlines: Effective immediately, masks are no longer required at United on domestic flights, select international flights (dependent upon the arrival country's mask requirements) or at U.S. airports.

"While this means that our employees are no longer required to wear a mask - and no longer have to enforce a mask requirement for most of the flying public - they will be able to wear masks if they choose to do so, as the CDC continues to strongly recommend wearing a mask on public transit,'' the airline said in a statement. "We will continue to closely monitor the situation in the event of changes.''

►Southwest Airlines: Effectively immediately, passengers and employees may choose whether they would like to wear a mask.

"We understand there are a number of opinions on this topic, and we ask that you respect and support the individual decisions made by others - that is how we will show hospitality and make customers and cohearts (Southwest employees) feel welcomed, cared for, and appreciated,'' Steve Goldberg, Southwest's senior vice president of operations and hospitality said in a memo to employees late Monday.

"We will continue to monitor developments and let's continue to focus on maintaining a safe operation and showing hospitality to each other and to our customers,'' the memo said.

►Alaska Airlines: Masks are optional in U.S. airports and onboard aircraft, effective immediately.

"While the Transportation Security Administration, TSA, is no longer enforcing its mask mandate, it may take time for individual airports to roll back their mask requirements,'' the airline said in a statement. "Out of an abundance of caution, we recommend guests defer to local port guidance when traveling, including wearing a mask if directed to do so. Guests must also continue to wear masks on flights both to and from Canada."

►JetBlue Airways: Effective immediately, masks are not required in airport terminals or on the plane, and employees will no longer make announcements enforcing the mask mandate.

"Customers of course remain free to wear them if they choose,'' the airline said in a memo to employees.

"This sudden end to the mask mandate may be confusing for some customers,'' the memo said. "Given the immediate nature of this change, our website and other customer-facing materials may continue to say a mask is required. We will begin removing these notices, and will also need be prepared to reinstate them if necessary.''

►Frontier Airlines: Effective immediately, passengers and employees are no longer required to wear masks on Frontier flights. For international travel, mask requirements remain dependent on the arrival/departure country's regulations.

"Following today's ruling by a federal district court judge in Florida that the Biden administration's mask mandate is unlawful, the mandate is no longer in effect while the ruling is being reviewed."

"Please note that individual airports and municipalities may still require masks so customers and team members should continue to abide by mask rules within any facility that may require it,'' the airline said in a statement.

►Spirit Airlines: Face masks are now optional on flights for passengers and crew.

"We understand some guests may want to continue wearing face coverings on flights, and that's perfectly fine under our optional policy," the airline said in a statement. "For our guests traveling internationally, please remember to check country-specific airport requirements before traveling."