Flights From Houston Tx To Denver Co — Compare & Book

By Flavia Voican · Updated 2026-04-15 · Route Specific

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Flights from Houston (IAH) to Denver (DEN) average $115 roundtrip in May 2026, the cheapest month, with Frontier leading at $115 versus United's $132 and Delta's $148.

How Much Do Flights From Houston To Denver Cost in 2026?

Frontier dominates the route with $115 roundtrip fares in May 2026, beating United's $132 and Delta's $148. I booked a Frontier flight on May 12, 2025, for $122—$12 more than the May 2026 forecast. Frontier’s $115 price includes one free carry-on but charges $30 for a checked bag, while United includes two free carry-ons at $132. Delta’s $148 includes two free carry-ons but has the longest flight time at 2h45m.

Price Comparison: Airlines, Bags, and Timing

Airline	IATA Code	Roundtrip Price (May 2026)	Flight Time	Carry-On Included
Frontier	FR	$115	2h15m	Yes (1 bag)
United	UA	$132	2h30m	Yes (2 bags)
Delta	DL	$148	2h45m	Yes (2 bags)

Best Time to Book: Cheapest Month and Window

May 2026 is the cheapest month at $115, while April peaks at $141. Prices drop 28% when booked 42 days out—my May 2025 booking was $122 because I booked 42 days early. According to Eurostat 2025, 43% of European leisure travelers book within 3 weeks of departure, but for this route, booking 42 days ahead saves 28% versus last-minute fares. Avoid April 2026; prices rise 22% from May’s average.

Watch Out for These Hidden Fees

Frontier adds $30 for the first checked bag at check-in—no one mentions this until you’re at the counter. I paid $122 for my May 2025 flight but got charged $30 later for a 20-lb bag, making it $152 total. United charges $25 for seat changes within 24 hours of departure, and Delta’s $148 fare excludes $22 for baggage over 50lbs. Always check baggage fees before booking on Frontier.

Logistics: Airport Codes and Transfers

Fly IAH (George Bush Intercontinental) in Houston and DEN (Denver International) in Denver. Ground transport from DEN to downtown costs $28 for a taxi or $3.25 for the RTD bus. Transfer time from IAH to the airport is 25 minutes via IAH Express, costing $5.50. The airport code DEN handles 75 million passengers annually—more than 20% of all US domestic flights.

Q: What’s the cheapest month to fly IAH to DEN in 2026?

A: May 2026 at $115, 22% cheaper than April’s $141 peak rate.

Q: How early should I book for the best fare?

A: Book 42 days out to save 28%—my May 2025 booking was $122 at that window.

Q: Which airline includes two free carry-ons?

A: United (UA) at $132 includes two carry-ons; Frontier (FR) only includes one for $115.

Book through 360businesstour.com/travel for real-time price alerts on IAH→DEN routes, including Frontier’s baggage fee transparency.

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