ON TIMEBOARD

BOI → PDX on time

Boise /Gowen (Boise, ID) to Portland (Portland, OR). Every scheduled flight, September 2025 to August 2026.

On time
90%
arrived < 15 min late
Cancelled
0.8%
1,744 flights
Typical arrival
−9 min
median vs schedule
When late
+71 min
average delay
Flights / day
5
1 airline

90% of flights from Boise to Portland arrived on time over the past 12 months. That is better than the typical U.S. route. The 5 a.m. departures ran on time 95% of the time; the 8 p.m. ones 84%. 4% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for BOI → PDX: when a flight was late, it was under 45 minutes late 54% of the time. About 1 in 31 flights landed an hour or more late, and 1 in 145 three hours or more; 0.7% were cancelled outright.

Share of all 1,744 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
Alaska Airlines1,74490%0.8%−9 min3.3%+71 minAlaska Airlines 41%, Horizon Air 39%, SkyWest 20%

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at BOI). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%5 a.m. departures: 95% on time (269 flights)955a6 a.m. departures: too few flights (96 flights)6a7 a.m. departures: too few flights7a8 a.m. departures: too few flights (21 flights)8a9 a.m. departures: 93% on time (341 flights)939a10 a.m. departures: too few flights (1 flights)10a11 a.m. departures: too few flights11anoon departures: too few flights (31 flights)12p1 p.m. departures: 89% on time (329 flights)891p2 p.m. departures: too few flights2p3 p.m. departures: too few flights3p4 p.m. departures: 88% on time (330 flights)884p5 p.m. departures: too few flights5p6 p.m. departures: too few flights6p7 p.m. departures: too few flights (20 flights)7p8 p.m. departures: 84% on time (306 flights)848p
BOI → PDX, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

Last flight of the day

On BOI → PDX, each airline's last flight of the day was cancelled 1.4% of the time, against 0.6% for its earlier flights (2.4× as often). It arrived 3+ hours late 0.8% of the time (earlier flights: 0.7%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
Alaska Airlines8:28 p.m.1.4%0.8%0.6%first flight 5:57 a.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

If you need to be in PDX tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: April (94%). Worst: January (83%).

40%70%100%Jan: 83% on time (430 flights)83JanFeb: 86% on time (386 flights)86FebMar: 87% on time (438 flights)87MarApr: 94% on time (433 flights)94AprMay: 91% on time (464 flights)91MayJun: 91% on time (450 flights)91JunJul: 90% on time (448 flights)90JulAug: 90% on time (463 flights)90AugSep: 91% on time (467 flights)91SepOct: 90% on time (459 flights)90OctNov: 91% on time (446 flights)91NovDec: 87% on time (462 flights)87Dec

By day of week

DayFlightsOn timeCancelled
Monday26595%0.0%
Tuesday24793%0.8%
Wednesday24791%0.4%
Thursday25888%1.2%
Friday25986%0.8%
Saturday20989%1.4%
Sunday25989%0.8%

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Late inbound plane 63%Airline (crew, maintenance, ops) 30%Air traffic & airport (NAS) 5%Severe weather 2%

Cancellations: air traffic/airport 8 · airline 5

Month by month

60%80%100%Sep 2023Jan 2024Jan 2025Jan 2026Sep 2023: 92% on time, 0.0% cancelledOct 2023: 87% on time, 0.0% cancelledNov 2023: 97% on time, 0.0% cancelledDec 2023: 94% on time, 0.0% cancelledJan 2024: 73% on time, 3.8% cancelledFeb 2024: 91% on time, 0.0% cancelledMar 2024: 86% on time, 0.7% cancelledApr 2024: 91% on time, 0.0% cancelledMay 2024: 91% on time, 0.0% cancelledJun 2024: 96% on time, 0.6% cancelledJul 2024: 93% on time, 0.0% cancelledAug 2024: 91% on time, 0.0% cancelledSep 2024: 89% on time, 0.0% cancelledOct 2024: 91% on time, 0.0% cancelledNov 2024: 91% on time, 0.6% cancelledDec 2024: 85% on time, 0.6% cancelledJan 2025: 83% on time, 0.0% cancelledFeb 2025: 74% on time, 2.9% cancelledMar 2025: 84% on time, 0.7% cancelledApr 2025: 93% on time, 0.0% cancelledMay 2025: 95% on time, 0.0% cancelledJun 2025: 86% on time, 0.0% cancelledJul 2025: 93% on time, 0.0% cancelledAug 2025: 88% on time, 0.0% cancelledSep 2025: 93% on time, 0.7% cancelledOct 2025: 93% on time, 0.7% cancelledNov 2025: 86% on time, 5.6% cancelledDec 2025: 83% on time, 0.0% cancelledJan 2026: 92% on time, 0.0% cancelledFeb 2026: 94% on time, 0.0% cancelledMar 2026: 92% on time, 0.0% cancelledApr 2026: 96% on time, 0.0% cancelledMay 2026: 87% on time, 0.7% cancelledJun 2026: 91% on time, 1.4% cancelledJul 2026: 85% on time, 0.0% cancelledAug 2026: 91% on time, 0.0% cancelled
Share of flights on time, by month (hover a point for cancellations)
BOI → PDX, monthly on-time and cancellation rate.

Flight numbers on this route

Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.

FlightDepartsFlightsOn timeCancelledTypical arrivalOperated by
AS 22091:29 p.m.14294%0.0%−8 minHorizon Air
AS 2294:23 p.m.20387%0.0%−10 minAlaska Airlines

Worst days in the past year

DateFlightsOn timeCancelled
Mar 14, 2026425%0
Nov 21, 2025425%0
Dec 19, 2025540%0
Jul 23, 2026540%0
Jun 18, 2026540%0

Questions

How often are flights from BOI to PDX on time?

90% of 1,744 scheduled flights from Boise, ID to Portland, OR arrived within 15 minutes of schedule between September 2025 and August 2026. 0.8% were cancelled.

What is the best time of day to fly BOI to PDX?

Flights scheduled to leave at 5 a.m. were the most reliable (95% on time). The 8 p.m. departures were the least (84%).

What month has the most delays from BOI to PDX?

January (83% on time). The best month is April (94%), over 2023–2026.

Is the last flight of the day from BOI to PDX more likely to be cancelled?

Yes. Each airline's last BOI–PDX flight of the day was cancelled 1.4% of the time over the past year, against 0.6% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.