Showing Southwest only (incl. its regional partners)All airlines ×

914 nonstop flights · Aug 2025 – Jul 2026 · US DOT on-time records, all US airlines

Leave before 9 am: 94% depart on time. After 4 pm it’s 2 in 5.

Best time to leave 5–6 am 89% arrive on time from BOS

Time of day × airport

Share of this route’s flights leaving within 15 minutes, by airport and scheduled departure hour, over Aug 2025 – Jul 2026. Blank: no flights then (or fewer than 40 in the year).

BOS

% of this route’s flights leaving within 15 min (small number: flights in the Jun 6 – Jul 31, 2026 schedule): 85+75–8465–7455–64under 55

Pick an hour to see this route’s flights leaving then.

Flights, best and worst

Flights in the Jun 6 – Jul 31, 2026 schedule that ran 150+ times in the year. Times are local. Pick a flight for its history.

No Southwest flight on this route ran 150+ times in the year.

All 5 Southwest flights in the current schedule

Every flight that flew in the Jun 6 – Jul 31, 2026 schedule, with its record over Aug 2025 – Jul 2026. Times are local. Click a column to sort.


WN 4156	BOS 06:25	DEN 08:50	4h 25m	58	88%	0.0%	33 min
WN 4208	BOS 11:35	DEN 14:05	4h 30m	33	70%	0.0%	36 min
WN 887	BOS 12:50	DEN 15:20	4h 30m	16	58%	6.2%	40 min
WN 888	BOS 16:45	DEN 19:25	4h 40m	16	56%	0.0%	101 min
WN 742	BOS 17:30	DEN 20:10	4h 40m	42	29%	0.0%	72 min

Nonstops by airline and airport

Arriving within 15 minutes, Aug 2025 – Jul 2026. Pick a row to see that airline’s flights on that airport pair.


Southwest	BOS	DEN	4h 45m	67%	1.0%	914	Flying now

Flying on a particular day? Pick a date above and the same ranking uses our forecast odds for each flight that day: Tomorrow.

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