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SEA vs HLN - 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
SEA

Seattle, WA

Seattle, Washington

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Airport B
HLN

Helena, MT

Helena, Montana

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Key Performance Metrics

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

Metric SEA HLN
On-Time Rate (higher is better) 83.1% 89.2%
Avg Delay (lower is better) 63.4 min 99.0 min
Delay Rate (lower is better) 16.9% 10.8%
Cancellation Rate (lower is better) 0.73% 0.66%
Total Flights 1,871,155 17,569
Delayed Flights 315,819 1,889
Cancelled Flights 13,720 116
Top Delay Cause Carrier Carrier

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

Delay Cause Breakdown

SEA - Seattle, WA

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

HLN - Helena, MT

Carrier 51.3%
Late Aircraft 18.2%
NAS 15.3%
Weather 15.2%
Security 0.0%

Top Routes

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%

Top routes from HLN

Route Flights On-Time
HLN → SLC
Salt Lake City
4,471 93.5%
SLC → HLN
Helena
4,470 94.2%
DEN → HLN
Helena
3,036 81.5%
HLN → DEN
Denver
3,034 81.2%
HLN → SEA
Seattle
677 84.8%
SEA → HLN
Helena
677 86.7%

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.