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

The best bet has a stop: United via Dulles (6h 55m) reaches Denver on time 92% of the time, against 73% on the nonstop.

Nonstops (seasonal or thin)


United	PWM	DEN	4h 38m	73%	0.0%	214	Flying now

Best connections, any airlines

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 Portland). Layovers up to 4 hours. Pick a connection for the details.


United Details →	PWM 06:00 → ORD 08:00UA 723	2h 54m Chicago	ORD 10:54 → DEN 12:45UA 581	8h 45m	100%	97%
United Details →	PWM 05:15 → IAD 07:00UA 1926	3h 13m Dulles	IAD 10:13 → DEN 12:05UA 1865	8h 50m	100%	93%
Delta + Unitedtwo ticketsDetails →	PWM 06:00 → ATL 08:45DL 1515	2h 25m Atlanta	ATL 11:10 → DEN 12:28UA 1327	8h 28m	99%	89%
Delta + Unitedtwo ticketsDetails →	PWM 06:00 → LGA 07:30DL 5799 · flown by Republic	2h 30m New York	LGA 10:00 → DEN 12:20UA 716	8h 20m	100%	88%
Southwest Details →	PWM 05:35 → BWI 07:15WN 4674	2h 25m Baltimore	BWI 09:40 → DEN 11:25WN 275	7h 50m	98%	83%
American Details →	PWM 07:16 → CLT 09:46AA 2966	1h 44m Charlotte	CLT 11:30 → DEN 12:56AA 1758	7h 40m	97%	78%
United Details →	PWM 09:55 → IAD 11:46UA 3465 · flown by Republic	1h 02m Dulles	IAD 12:48 → DEN 14:42UA 1587	6h 47m	87%	76%
Southwest Details →	PWM 07:40 → MDW 09:15WN 3415	1h 55m Chicago	MDW 11:10 → DEN 12:40WN 2960	7h 00m	98%	76%
Tight connection: often missed
Delta Details →	PWM 18:59 → ATL 21:56DL 488	1h 03m Atlanta	ATL 22:59 → DEN 00:23 +1DL 956	7h 23m	71%	51%
American Details →	PWM 18:01 → CLT 20:36AA 2352	49m Charlotte	CLT 21:25 → DEN 23:01AA 3156	6h 58m	65%	41%
United Details →	PWM 17:00 → ORD 19:00UA 1182	1h 00m Chicago	ORD 20:00 → DEN 22:01UA 767	7h 01m	51%	36%

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 15m · leaves 05:15 3%

ATL · 1h 05m · leaves 06:00 6%

Afternoon and evening

BWI · 55m · leaves 17:20 28%

ATL · 1h 03m · leaves 18:59 29%

CLT · 49m · leaves 18:01 35%

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