Travel from July through mid-November. Some routes are seasonal ending in early August.
Most routes are only flown on specific days of the week so you'll have to click around to find available flights. Click on the fare details below for details. A 7-day advanced purchase is required.
Tickets must be booked by 11:59 pm ET, July 18, 2019.
All fares are nonstop!
These fares only include one small personal item. Checked bag fees start at $30 each way when purchased during the initial booking. Larger carry-on bag fees start at $35 each way.
Seats will be assigned at random upon check-in for these prices. You may pay a fee to choose a specific seat.
Frontier offers the Works bundle, which can be added to any flight during the initial booking. It includes a standard carry-on bag plus a personal item, one free checked bag, seat selection (including stretch seating), priority boarding, flight flexibility, and refundability. This is a value if you want all of these amenities, but chances are you can get away with just adding what you need a la carte for cheaper.
Searching Frontier's site, I found flights departing Denver DEN on Wednesday, August 28, returning from Cancun CUN on Wednesday, September 4, for $186 roundtrip.
As you can see in the screenshots, the majority of this ticket price is taxes and carrier-imposed fees. The $38 (per passenger) "Carrier Interface Charge" is Frontier's online booking fee, which can be avoided by booking at an airport ticket counter. Higher bag fees may apply to tickets booked at the airport.