Itineraries flown on 20+ days in the Jun 6 – Jul 31, 2026 schedule · each leg’s record Aug 2025 – Jul 2026

Connect in the morning. The same 75-minute layover misses 6% of the time at 12 pm and 1 time in 5 at 5 pm.

Nonstops (seasonal or thin)


United	DEN	BUF	3h 17m	73%	0.0%	294	Flying now
Southwest	DEN	BUF	3h 05m	62%	0.4%	258	Flying now
Frontier	DEN	BUF	3h 14m	83%few flights	0.0%	35	Not flying now

Best connections, any airlines

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Buffalo on time. Total trip = scheduled departure to arrival, layover included (Buffalo is 2 h ahead of Denver). Layovers up to 4 hours. Pick a connection for the details.


United + Americantwo ticketsDetails →	DEN 23:59 → PHL 05:31UA 1214	3h 13m Philadelphia	PHL 08:44 → BUF 10:18 +1AA 5925 · flown by Piedmont	8h 18m	98%	91%
United + Americantwo ticketsDetails →	DEN 23:59 → BOS 05:58UA 2656	3h 05m Boston	BOS 09:03 → BUF 10:52 +1AA 4666 · flown by Republic	8h 53m	100%	90%
United Details →	DEN 23:59 → IAD 05:27UA 1924	2h 58m Dulles	IAD 08:25 → BUF 09:51 +1UA 3514 · flown by Republic	7h 52m	100%	90%
Delta Details →	DEN 00:59 → DTW 05:48DL 1096	1h 19m Detroit	DTW 07:07 → BUF 08:23DL 3639 · flown by SkyWest	5h 24m	94%	87%
Delta Details →	DEN 00:40 → ATL 05:42DL 302	3h 22m Atlanta	ATL 09:04 → BUF 11:09DL 1384	8h 29m	100%	86%
Delta Details →	DEN 23:59 → JFK 05:48DL 758	2h 12m New York	JFK 08:00 → BUF 09:41 +1DL 5223 · flown by Endeavor	7h 42m	100%	85%
Frontier + Southwesttwo ticketsDetails →	DEN 23:59 → TPA 05:32F9 2746	3h 23m Tampa	TPA 08:55 → BUF 11:35 +1WN 484	9h 36m	97%	84%
Southwest Details →	DEN 23:50 → BWI 05:15WN 1501	1h 40m Baltimore	BWI 06:55 → BUF 08:10 +1WN 4566	6h 20m	98%	84%
Tight connection: often missed
American Details →	DEN 15:13 → PHL 20:59AA 1759	1h 21m Philadelphia	PHL 22:20 → BUF 23:53AA 5911 · flown by Piedmont	6h 40m	67%	53%
JetBlue Details →	DEN 10:24 → BOS 16:25B6 494	1h 15m Boston	BOS 17:40 → BUF 19:19B6 1115	6h 55m	75%	50%

Same layover, different day-part

How often the first flight arrives too late to connect (45 min minimum), for one-ticket layovers of 45–80 minutes.

Morning

IAD · 1h 18m · leaves 06:13 6%

DTW · 1h 19m · leaves 00:59 6%

Afternoon and evening

IAD · 1h 15m · leaves 15:40 19%

ORD · 1h 12m · leaves 13:25 21%

BOS · 1h 15m · leaves 10:24 25%

Delays build through the day, so an afternoon first leg eats the layover. A short connection is fine early in the morning and a gamble later on.

Mixing airlines

One ticketMiss it and the airline rebooks you; bags go through. 45 min is enough.

Separate ticketsMiss it and you buy a new ticket. Re-check bags, clear security again: we require 90 min.

The table above includes two-ticket connections (marked “two tickets”), held to the 90-minute minimum. One ticket only →

Regional partners count as the airline that sells them: SkyWest flying Delta Connection is one Delta ticket.

How these are worked out. Makes the connection: share of the last year’s flights where the first flight arrived with at least 45 minutes to spare (90 on separate tickets). Arrives on time: first flight not cancelled × connection made × second flight not cancelled and arriving within 15 minutes. Not yet counted: the second flight also leaving late (which helps), gate-to-gate distance at the hub, and rebooking after a missed connection.

About this data: US DOT on-time records, Aug 2025 – Jul 2026, all US airlines; regional flights count under the airline that sells them. Schedules (which flights and connections exist, and their times) are as of Jun 6 – Jul 31, 2026; seasonal flights outside that window aren’t ranked. Rebuilt monthly. JSON