The company now expects June revenue to be down 70% to 75% from a year earlier, improved from its previous projections for a decline of 80% to 85%.
Southwest has enough cash to operate for the next two years, up from its previous forecast of 20 months. The airline said that it had cash and short-term investments of $13.9 billion.
"The company has continued to experience a modest improvement in passenger demand and bookings in June 2020 - primarily leisure-driven demand," Southwest said.
Late Tuesday, Southwest said it planned to keep middle seats empty through at least Sept. 30 as part of its social-distancing efforts.
The Dallas airline also said it would require customers to sign off on a customer-health declaration, a form saying that they do not have covid-19 and are aware that they must wear face coverings.
Southwest will board in groups of 10 in order to allow social distancing and will place floor markers and signage encouraging distance throughout the gating area.
Several U.S. airlines are saying that they will ban passengers who refuse to wear face masks. These include Alaska Airlines (ALK) - Get Report, American Airlines (AAL) - Get Report, Delta (DAL) - Get Report, Hawaiian Airlines (HA) - Get Report, JetBlue (JBLU) - Get Report, United (UAL) - Get Report and Southwest, the Airlines for America trade group said Monday.
The Association of Flight Attendants-CWA, which represents about 50,000 flight attendants at 19 airlines, also released a statement about face coverings, calling the practice important.
Southwest shares at last check were down 0.6% to $36.35.