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

No clear winner: United’s BUF → IAD flights land within a few points of 85% on time whatever the hour.

Nonstops


United	BUF	IAD	1h 21m	85%	2.3%	1,151	Flying now

Best connections, one ticket

Most reliable Quickest (80%+ on time)

Ranked by chance you reach Dulles on time. Total trip = scheduled departure to arrival, layover included. Layovers up to 4 hours. Pick a connection for the details.


United Details →	BUF 07:00 → ORD 08:05UA 5820 · flown by SkyWest	3h 02m Chicago	ORD 11:07 → IAD 14:12UA 1869	7h 12m	100%	86%
Delta Details →	BUF 06:29 → DTW 07:42DL 2898	1h 08m Detroit	DTW 08:50 → IAD 10:23DL 2884	3h 56m	93%	83%
Delta Details →	BUF 06:00 → ATL 08:10DL 2664	1h 40m Atlanta	ATL 09:50 → IAD 11:39DL 1444	5h 38m	97%	80%
American Details →	BUF 06:01 → CLT 08:01AA 1204	3h 04m Charlotte	CLT 11:05 → IAD 12:38AA 5220 · flown by PSA	6h 37m	98%	80%
Delta Details →	BUF 07:00 → JFK 08:30DL 5284 · flown by Endeavor	1h 46m New York	JFK 10:16 → IAD 11:48DL 5835 · flown by Republic	4h 48m	95%	78%
Delta Details →	BUF 12:04 → DTW 13:23DL 3636 · flown by SkyWest	1h 47m Detroit	DTW 15:10 → IAD 16:42DL 1787	4h 38m	93%	76%
Delta Details →	BUF 17:12 → ATL 19:25DL 2266	3h 28m Atlanta	ATL 22:53 → IAD 00:44 +1DL 2549	7h 32m	99%	73%
United Details →	BUF 10:57 → ORD 11:57UA 705	1h 33m Chicago	ORD 13:30 → IAD 16:30UA 2794	5h 33m	95%	72%
Tight connection: often missed
United Details →	BUF 13:54 → ORD 14:55UA 4381 · flown by GoJet	58m Chicago	ORD 15:53 → IAD 19:02UA 2437	5h 08m	71%	48%
American Details →	BUF 19:35 → CLT 21:36AA 1614	1h 09m Charlotte	CLT 22:45 → IAD 00:10 +1AA 1242	4h 35m	70%	27%

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

DTW · 1h 08m · leaves 06:29 7%

Afternoon and evening

ATL · 1h 09m · leaves 19:24 14%

EWR · 1h 19m · leaves 19:00 15%

CLT · 1h 09m · leaves 19:35 30%

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.


Delta DL 2898 BUF 06:29 → DTW United UA 3500 DTW 10:13 → IAD Connection details →	2h 31m	5h 21m	96%	88%
American AA 1204 BUF 06:01 → CLT United UA 4012 CLT 10:27 → IAD Connection details →	2h 26m	5h 54m	96%	82%
American AA 5873 BUF 05:20 → PHL United UA 6235 PHL 10:39 → IAD Connection details →	3h 53m	6h 35m	98%	82%

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