PlainFlights

IAD vs SEA - Airport Comparison

Select two airports to compare on-time performance, delays, cancellations, and top routes using U.S. Department of Transportation Bureau of Transportation Statistics (BTS) data (2020–2025) across all 50 states. See our methodology for how metrics are computed.

Airport A
IAD

Washington, DC

Washington, Virginia

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Airport B
SEA

Seattle, WA

Seattle, Washington

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Key Performance Metrics

BTS on-time performance data, 2020–2025 cumulative.

Metric IAD SEA
On-Time Rate (higher is better) 84.1% 83.1%
Avg Delay (lower is better) 81.3 min 63.4 min
Delay Rate (lower is better) 15.9% 16.9%
Cancellation Rate (lower is better) 1.05% 0.73%
Total Flights 618,145 1,871,155
Delayed Flights 98,139 315,819
Cancelled Flights 6,473 13,720
Top Delay Cause Carrier Carrier

✓ / ▲ indicates the more favorable value. Data: BTS On-Time Performance, 2020–2025.

Delay Cause Breakdown

IAD - Washington, DC

Carrier 37.9%
Late Aircraft 30.2%
NAS 22.4%
Weather 9.5%
Security 0.1%

SEA - Seattle, WA

Carrier 44.3%
Late Aircraft 28.6%
NAS 21.0%
Weather 5.8%
Security 0.3%

Top Routes

Top routes from IAD

Route Flights On-Time
IAD → ATL
Atlanta
20,387 84.2%
ATL → IAD
Washington
20,375 84%
DEN → IAD
Washington
17,394 79.1%
IAD → DEN
Denver
17,372 83.1%
CLT → IAD
Washington
13,324 83.6%
IAD → CLT
Charlotte
13,287 83.5%

Top routes from SEA

Route Flights On-Time
SEA → LAX
Los Angeles
41,859 84%
LAX → SEA
Seattle
41,819 86.2%
SEA → ANC
Anchorage
41,143 77.5%
ANC → SEA
Seattle
41,064 85.8%
PHX → SEA
Seattle
38,561 84.3%
SEA → PHX
Phoenix
38,549 82.3%

Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data (2020–2025) Bureau of Transportation Statistics (BTS), On-Time Performance Data (2020–2025) On-time rates exclude cancelled and diverted flights. PlainFlights is not affiliated with BTS or the DOT

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This tool queries live on-time, delay, and cancellation figures for the two selected airports from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.