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Route Reliability

Seattle → Salt Lake City

SEA–SLC · 689 miles · Seattle–Tacoma International Airport to Salt Lake City International Airport

87
Pretty Reliable
WanderNerd Reliability Score
84%
Arrive within 15 minutes
1 min
Average arrival delay
1.0%
Cancelled
4,144
Flights in the data

Data through May 2026.

Who flies it best

Ranked by on-time arrivals. Historical results, not predictions.

  1. 1.Delta Air Lines87%2,218 flights
  2. 2.Alaska Airlines79%1,819 flights
  3. 3.Frontier Airlines70%107 flights

What the data says

Morning flights do better here.

SEA–SLC flights departing between 6–9 AM arrived on time 94% of the time, versus 79% between 3–6 PM.

Wednesday comes out ahead.

A small edge: 85% on time on Wednesdays against 81% on Thursdays.

Delta Air Lines has a clear lead on this route.

Delta Air Lines arrived on time 87% of the time on this route; Frontier Airlines managed 70%.

Ticking up lately.

SEA–SLC flights arrived on time 88% of the time over the last three months in the data, compared with 81% in the three months before that.

Best historical flights

Ranked by on-time arrivals, minimum 100 flights. Past performance, not a promise.

Top flights by on-time rate

More flights on this route

The breakdown

On-time by weekday
  • Mon84%(649 flights)
  • Tue85%(542 flights)
  • Wed85%(537 flights)
  • Thu81%(606 flights)
  • Fri83%(639 flights)
  • Sat84%(516 flights)
  • Sun84%(610 flights)
On-time by departure window
  • 3–6 AM93%(364 flights)
  • 6–9 AM94%(464 flights)
  • 9 AM–12 PM81%(1128 flights)
  • 12–3 PM84%(488 flights)
  • 3–6 PM79%(828 flights)
  • 6–9 PM81%(826 flights)
  • 9 PM–12 AM—(1 flights)
On-time trend by month
86%
May

Jun 78% → May 86% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202578%373
July 202577%389
August 202578%404
September 202589%397
October 202586%360
November 202588%289
December 202577%303
January 202683%301
February 202684%291
March 202685%321
April 202693%322
May 202686%349

Keep nerding

Based on 4,144 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.