It's been a while since Frontier has dropped its fares this low. These sales seemed to occur almost weekly at the end of last year, but have been rare since the beginning of the year. Base fares of $1 each way add up to $39 (or lower) roundtrip after taxes and booking fees. Fares can also be bought one-way for just $20. Choose from around 25 routes at this incredibly low price. Many more routes are available for under $100 roundtrip.

If you're unfamiliar with Frontier Airlines and how this ultra-low-cost carrier differs from other airlines, read up on Everything You Need to Know Before You Fly Frontier.

Availability is limited so you must be somewhat flexible to find the lowest price. Travel days will vary by route, but generally, fares are available on scattered dates through mid-February. A few routes may have some availability through March or April.

Most of these routes are only flown a few times each week so be sure to check out the specifics in the fare details on your route.

Tickets must be booked by 11:59 pm ET, January 25, 2019, or before seats sell out.

Nonstop fares include:

Greenville to Tampa $34 roundtrip

Charlotte to Tampa $37 roundtrip

Salt Lake City to Las Vegas $39 roundtrip

Atlanta to Orlando $39 roundtrip

Philadelphia to Nashville $39 roundtrip

Kansas City to Denver $39 roundtrip

Sacramento to Las Vegas $39 roundtrip

Atlanta to Sarasota $39 roundtrip

Norfolk to Orlando $39 roundtrip

Raleigh to West Palm Beach $39 roundtrip

Raleigh to Ft. Myers $39 roundtrip

Birmingham to Orlando $39 roundtrip

Chicago to Palm Springs $49 roundtrip

These fares all work in reverse as well. You'll have to decline all extras to get the lowest price.

Keep in mind that Frontier charges extra for any bags larger than a small personal item (small backpack, purse, etc.). Pack super light to get the lowest price. Checked bag fees start at $30 each way. Larger carry-on bag fees start at $35 each way.

For a complete look at baggage fees on all airlines, check out our Bag Fee Chart.

As an example booking, I found seats departing Philadelphia PHL on Monday, February 4, returning from Nashville BNA on Friday, February 8, for $39 roundtrip.

Featured image via Shutterstock.