Due to the holiday week, Southwest has posted their sale a day earlier this week. This promotion dubbed the "July 4-day Sale is valid for travel in late summer and fall months, even though the website says September travel. These deals fall in line with Southwest's usually weekly offerings, but with over 1,100 routes marked down, it's one of the more encompassing sales this year.

Seats are available on Monday through Thursday and Saturdays from August 21 through December 19, 2018. Flights are blacked out on August 31, September 3, November 20-21 & November 24-26, 2018. As always, pack all you want because Southwest still flys two checked bags for free.

All tickets must be booked by Thursday, July 5, 2018, at 11:59 pm.

Please note, these fares are only available on Southwest.com. Other carriers regularly match these sale fares, so be sure to compare to find the best deal.

Sample nonstop sale fares include:

Las Vegas to Long Beach $90 roundtrip

Los Angeles to San Francisco $118 roundtrip

Oakland to San Diego $118 roundtrip

Washington DC-Reagan to Providence $118 roundtrip

Tulsa to Dallas-Love $118 roundtrip

Portland to San Jose, CA $134 roundtrip

Boston to Baltimore $136 roundtrip

Salt Lake City to Los Angeles $152 roundtrip

Ft. Lauderdale to Atlanta $156 roundtrip

Houston-Hobby to Oklahoma City $158 roundtrip

Detroit to Chicago-Midway $162 roundtrip

St. Louis to Des Moines $164 roundtrip

Washington DC-Dulles to Ft. Lauderdale $174 roundtrip

Chicago-Midway to Newark $176 roundtrip

Kansas City to Atlanta $182 roundtrip

Memphis to Tampa $186 roundtrip

Baltimore to Charlotte $188 roundtrip

Minneapolis to Nashville $194 roundtrip

Washington DC-Reagan to Orlando $198 roundtrip

New York-LaGuardia to Tampa $198 roundtrip