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DelayAtlas

Route reliability record

MCOSEA

Orlando to Seattle

Flights
1,822
Period
July 2025 to June 2026
Distance
2,554 mi
Carriers
2
BGRADE

This route lands a B, about a point worse than the national rate of 77.6%. About one flight in four 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 1,822 MCO to SEA flights, of which Alaska Airlines flew 1,103 at 77.4% on time.

Best time to fly MCO to SEA: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 85.5% of the time and Tuesday flights 78.5%, against 76.5% for the route overall.

The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

76.5%

Arrivals under 15 minutes late, of 1,798 completed flights

Avg delay

61 min

Across delayed arrivals only, not all flights

Cancelled

1.04%

National rate is 1.81%

Best carrier

Alaska

77.4% on time across 1,103 flights

These figures cover 1,822 flights between July 2025 and June 2026. The median arrival is 4 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 MCO to SEA

The two carriers here are closely matched: 2 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

On-time performance by carrier on MCO to SEA
AirlineFlightsOn timeAvg delayCancelledGrade
Alaska Airlines1,10377.4%57 min0.73%B+
Delta Air Lines71975.2%67 min1.53%B

No carrier stands out. Alaska tops the table at 77.4%, 2 points clear of the bottom, which is inside the range this kind of sample moves year to year.

Flight by flight

Flights on MCO to SEA

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.

Best ways to make this trip

The most reliable ways to fly Orlando to Seattle

Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.

Most reliable ways to fly from MCO to SEA
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. MCOSEAOrlando to SeattleAlaska Airlines76.8%77.4%0.73%8am–11am, ThuAS 395 07:00
2. MCOSEAOrlando to SeattleDelta Air Lines74.0%75.2%1.53%8am–11am, FriDL 347 09:00

Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.

Plan this trip by month, day and time

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 18 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am363 flights80.2%
  • 8am–11am633 flights85.5%
  • 11am–2pm
  • 2pm–5pm146 flights70.3%
  • 5pm–8pm646 flights67.2%
  • 8pm–5am34 flights71.9%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 85.5% of the time, against 67.2% for the evening window. That is 18 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 646 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 25 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

On-time rate by calendar month73J81F68M85A82M75J73J64A89S80O81N68D
Darker means more delays. Figures are on-time percentages.September best, August worst

August is the worst month at 63.6% on time, 25 points below September, the best at 89.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 166 flights.

Across the week, Tuesday is the strongest day at 78.5% on time and Saturday the weakest at 73.4%. 5 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week77.6Mon78.5Tue77.6Wed77.5Thu76.9Fri73.4Sat74.2Sun
Monday: 77.6 percent on time. Tuesday: 78.5 percent on time. Wednesday: 77.6 percent on time. Thursday: 77.5 percent on time. Friday: 76.9 percent on time. Saturday: 73.4 percent on time. Sunday: 74.2 percent on time

Delay causes

Why this route gets delayed

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 26,000 reported delay minutes.

  • Late-arriving aircraft
    36%
  • Carrier
    32%
  • National Airspace System
    23%
  • Extreme weather
    9%

36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 26,000 reported delay minutes here, that single category outweighs weather by 4 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 25,855 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 85.5% on time here.

Cancellations sit at 1.04% against a national 1.81%, which is ordinary. Diversions add another 0.27%.

Connections and stage length

What a delay here actually costs

6.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

At 2,554 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg is a different operation and performs like one: it runs 81.0% on time across 1,820 flights, 5 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 5 points of difference.

The sample behind these figures is 1,822 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 SEA after this flight

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 89.0% on time and August 63.6%, a swing of 25 points. If the dates move at all, move them out of August before you think about anything else. 1,798 completed flights over 12 months sit behind that.

Common questions

MCO to SEA questions

How often is MCO to SEA delayed?

About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.5% of the 1,822 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on MCO to SEA?

Alaska Airlines leads at 77.4% on time across 1,103 flights. Delta Air Lines is at the other end on 75.2%, a gap of 2 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

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

The 8am–11am departure window is the strongest at 85.5% on time. The 5pm–8pm window is the weakest at 67.2%, 18 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 August delays on MCO to SEA?

August is the weakest month at 63.6% on time, compared with 89.0% in September. Across the year that is 25 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. MCO to SEA and SEA to MCO are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

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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.