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DelayAtlas

Route reliability record

SEAPSC

Seattle to Pasco

Flights
1,818
Period
July 2025 to June 2026
Distance
172 mi
Carriers
2
B+GRADE

This route lands a B+, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 1,818 SEA to PSC flights, with a median arrival 7 minutes early.

Best time to fly SEA to PSC: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 89.3% of the time and Tuesday flights 88.4%, against 83.9% for the route overall.

Set against the rest of the country, this route's record is 6 points better than the US average of 77.6%. That gap is worth roughly 63 fewer late arrivals for every thousand flights.

Key figures

On time

83.9%

Arrivals under 15 minutes late, of 1,797 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

0.99%

National rate is 1.81%

Best carrier

SkyWest

84.9% on time across 1,542 flights

These figures cover 1,818 flights between July 2025 and June 2026. The median arrival is 7 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Which airline is most reliable on SEA to PSC

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on SEA to PSC
AirlineFlightsOn timeAvg delayCancelledGrade
SkyWest Airlines1,54284.9%66 min0.71%B+
Alaska Airlinesthin sample27677.7%39 min2.54%B

Flight by flight

Flights on SEA to PSC

The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am
  • 8am–11am431 flights89.3%
  • 11am–2pm255 flights76.0%
  • 2pm–5pm406 flights86.9%
  • 5pm–8pm72 flights80.3%
  • 8pm–5am654 flights81.7%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 76.0% on time against 89.3% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8pm–5am window is the busiest, with 654 flights scheduled in it.

Across the year

When delays peak on this route

Twelve months, one bar each, drawn from the same 1,818 flights. The strip shows how much of this route's record is set by the calendar rather than by the operation.

On-time rate by calendar month80J84F78M84A82M88J82J87A86S84O87N83D
Darker means more delays. Figures are on-time percentages.June best, March worst

Delays peak in March, when the on-time rate falls to 78.0%. June is the strongest month at 87.6%. Moving a flexible trip across that boundary buys 10 points. October was the busiest month here, with 213 flights.

Across the week, Tuesday is the strongest day at 88.4% on time and Thursday the weakest at 80.2%. 8 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week84.8Mon88.4Tue85.4Wed80.2Thu81.1Fri85.8Sat81.7Sun
Monday: 84.8 percent on time. Tuesday: 88.4 percent on time. Wednesday: 85.4 percent on time. Thursday: 80.2 percent on time. Friday: 81.1 percent on time. Saturday: 85.8 percent on time. Sunday: 81.7 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Carrier accounts for 51% of the 17,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Carrier
    51%
  • Extreme weather
    21%
  • Late-arriving aircraft
    19%
  • National Airspace System
    9%
  • Security
    1%

Extreme weather accounts for 21% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.4 times the usual weather exposure. The split is drawn from 17,495 reported delay minutes.

The largest share of delay minutes, 51%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 8,914 of the 17,000 delay minutes reported here.

Cancellations sit at 0.99% against a national 1.81%, which is ordinary. Diversions add another 0.17%.

Connections and stage length

What a delay here actually costs

Badly late arrivals are rare here: only 4.3% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 172 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 88.3% on time across 1,819 flights, 4 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.

The sample behind these figures is 1,818 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

Work out the risk of missing a connection in PSC after this flight

What to do with this

Booking this route

Put together: take the 8am–11am departure, avoid March if the dates are flexible, and if two carriers are within a few dollars of each other, SkyWest is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 13 points, which is the most any booking decision can do. 1,797 completed flights over 12 months sit behind that.

Common questions

SEA to PSC questions

How often is SEA to PSC delayed?

About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 16.1% of the 1,818 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is SEA to PSC compared with the rest of the country?

83.9% of flights arrive on time here against a national 77.6%, a difference of 6 points in its favour. That is worth a B+ on this site's grading scale.

What time of day has the fewest delays on SEA to PSC?

The 8am–11am departure window is the strongest at 89.3% on time. The 11am–2pm window is the weakest at 76.0%, 13 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are March delays on SEA to PSC?

March is the weakest month at 78.0% on time, compared with 87.6% in June. Across the year that is 10 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Related

Where to go next

Direction matters. SEA to PSC and PSC to SEA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed SEA to PSC’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.