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 one-hour layover misses 5% of the time at 8 am and almost half the time at 7 pm.

Nonstops


Delta	BOS	DEN	4h 34m	85%	1.6%	372	Flying now
United	BOS	DEN	4h 35m	83%	1.1%	1,897	Flying now
JetBlue	BOS	DEN	4h 42m	71%	2.5%	685	Flying now
Southwest	BOS	DEN	4h 45m	67%	1.0%	914	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

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


United Details →	BOS 06:00 → ORD 07:58UA 1414	2h 56m Chicago	ORD 10:54 → DEN 12:45UA 581	8h 45m	100%	95%
United Details →	BOS 05:45 → IAD 07:23UA 1734	2h 50m Dulles	IAD 10:13 → DEN 12:05UA 1865	8h 20m	100%	91%
United Details →	BOS 06:21 → LAX 09:35UA 360	3h 11m Los Angeles	LAX 12:46 → DEN 16:16UA 360	11h 55m	100%	90%
Southwest Details →	BOS 05:50 → STL 07:45WN 752	57m St Louis	STL 08:42 → DEN 10:02WN 3910	6h 12m	99%	89%
United Details →	BOS 09:25 → IAD 11:07UA 2098	1h 41m Dulles	IAD 12:48 → DEN 14:42UA 1587	7h 17m	97%	87%
United Details →	BOS 08:15 → ORD 10:12UA 1834	2h 44m Chicago	ORD 12:56 → DEN 14:46UA 1150	8h 31m	100%	87%
United Details →	BOS 05:47 → IAH 08:50UA 1409	3h 43m Houston	IAH 12:33 → DEN 14:17UA 2168	10h 30m	100%	86%
Delta Details →	BOS 06:50 → ATL 09:33DL 695	3h 17m Atlanta	ATL 12:50 → DEN 14:04DL 957	9h 14m	98%	86%
Tight connection: often missed
Delta Details →	BOS 10:55 → LAX 14:07DL 2004	46m Los Angeles	LAX 14:53 → DEN 18:18DL 2176	9h 26m	67%	43%
Delta Details →	BOS 17:05 → JFK 18:43DL 5814 · flown by Republic	1h 07m New York	JFK 19:50 → DEN 22:45DL 424	7h 40m	68%	43%
United Details →	BOS 17:00 → ORD 19:00UA 2040	1h 00m Chicago	ORD 20:00 → DEN 22:01UA 767	7h 01m	55%	37%

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

STL · 57m · leaves 05:50 1%

LAX · 1h 20m · leaves 06:21 3%

DFW · 1h 19m · leaves 06:00 4%

Afternoon and evening

BWI · 50m · leaves 17:20 56%

BNA · 52m · leaves 14:20 71%

DAL · 50m · leaves 17:45 73%

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.


American AA 3324 BOS 05:10 → ORD United UA 581 ORD 10:54 → DEN Connection details →	3h 50m	9h 35m	99%	94%
Delta DL 2303 BOS 05:55 → MSP United UA 2232 MSP 11:34 → DEN Connection details →	3h 30m	8h 50m	99%	91%
Delta DL 1410 BOS 06:30 → AUS United UA 1541 AUS 12:55 → DEN Connection details →	3h 07m	9h 44m	96%	90%

Rank all connections, any airlines →

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