On Tuesday, Southwest Airlines launched a major flash sale featuring big discounts on domestic and international flights this fall. Travelers can take advantage of one-way fares as low as $49 (for select cities and dates) — as long as they book by June 9 at 11:59 pm.

Deals on domestic travel apply to nonstop flights on Tuesdays, Wednesdays, and Saturdays from August 23 through December 14. Cheap one-way fares out of Austin include Denver (starting at $79), New Orleans (starting at $79), Atlanta (starting at $99), Seattle (starting at $129), Las Vegas (starting at $129), Phoenix (starting at $129), San Diego (starting at $129), and more.

Austin travelers can fly to Dallas, El Paso, Harlingen, Houston, and Lubbock for as low as $49.

The sale does not apply to international flights out of Austin; those must originate at Houston's William P. Hobby Airport. Nonstop flights from Houston to Mexico include Mexico City (starting at $89), Cancun (starting at $119), Puerto Vallarta (starting at $129), and Cabo San Lucas (starting at $139). There are also discounted flights to Belize City (starting at $107); San Jose, Costa Rica (starting at $124); and Montego Bay, Jamaica (starting at $159). International flights must be on Mondays through Thursdays between August 23 and December 13.

Better get to booking. Southwest's sale ends Thursday, June 9, at 11:59 pm in the time zone of the originating city.