Delta Air Lines is cancelling flights that had been scheduled for Wednesday in St. Thomas as it prepares for Hurricane Irma to pass through the Caribbean.

Atlanta-based Delta said it will also delay its evening flights in San Juan, Puerto Rico, and is planning to assess facilities after the storm passes.

The airline didn't have any flights scheduled to St. Maarten on Wednesday, and was assessing infrastructure there to determine when to resume flights, according to Delta spokesman Michael Thomas.

He said Delta also canceled flights to St. Thomas in the Virgin Islands for Wednesday and expected to soon cancel flights to the Bahamas. Some other airports in the Caribbean were expected to close Wednesday evening.

Delta said its team of meteorologists expects the storm to begin curving north late Saturday afternoon, passing between Cuba and the Bahamas toward the southern tip of Florida. The airline said its strategic planners are working with employees at airports along the storm's path.

"Preparations are underway," said Delta's chief financial officer Paul Jacobson during remarks at an investor conference Wednesday. "This looks like a big storm and we're hopeful the damage can be kept to a minimum."

Southwest Airlines, the second-largest carrier at Hartsfield-Jackson International Airport, is cancelling flights to Punta Cana in the Dominican Republic and San Juan on Wednesday, Thursday and Friday

Dallas-based Southwest is also cancelling flights scheduled for Friday and Saturday to Nassau and Havana.

Southwest said it will cancel all flights through Saturday to and from Fort Lauderdale, Ft. Myers and West Palm Beach.

Hartsfield-Jackson is advising travelers to monitor their airline's communications channels.

Delta and Southwest are both allowing travelers to change their travel plans without paying certain charges if they had flights booked to cities in the hurricane's path during a set period.

— Stay up to date on the latest news on Atlanta airline travel by following  Atlanta Airport News Now  on Facebook.

MORE:

Hurricane Irma: Delta adding flights for Florida evacuees

Hurricane Irma: Live updates

Hurricane Irma: What is a Category 5 hurricane and what does it do?

Hurricane Irma now a category 5 storm with maximum winds of 175 mph

Hurricane Irma could affect Georgia next week

Georgia hotels fill up as Floridians prepare to flee Hurricane Irma

Hurricane Irma: Here is a list of items for a last-minute preparation kit Delta and Southwest are cancelling flights in the Caribbean due to Hurricane Irma.