Southwest Airlines Co said on Thursday it was seeing a slowdown in improving revenue trends in recent weeks, at a time when COVID-19 cases are rising in the United States.

"While the company expected the election to impact trends, it is unclear whether the softness in booking trends is also a direct result of the recent rise in COVID-19 cases," Southwest said.

"As such, the company remains cautious in this uncertain revenue environment."

Southwest said it continues to expect its November operating revenue to be between 60% and 65% compared to a year earlier, and forecast December operating revenue to drop to that range as well.

The US budget carrier said its October operating revenue fell 65%, but it was better than its expectation of a 65% to 70% drop.

Southwest said it expects its January 2021 capacity to decrease in the range of 35% to 40%, year-over-year, slowing from an expected 40% fall in the current quarter.