OnTimeRoutes
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Frontier Airlines ONT to SEA on-time performance

Frontier Airlines nonstop flights from Ontario to Seattle · Aug 2025 – Jul 2026

On-time arrivals
82%
arrived < 15 min late
Cancelled
0.6%
1 flights
Avg arrival delay
17 min
92 min when late
Rank on route
#4 of 4
route average 86% on time

Key facts

  • Frontier Airlines flights on ONT to SEA arrived on time 82% of the time in Aug 2025 – Jul 2026.
  • 0.6% were cancelled, and 5% arrived an hour or more late.
  • That ranks #4 of 4 airlines on this route, which averaged 86% on time overall.
  • The largest source of delay minutes was late-arriving aircraft (84%).

On-time trend by month

50%75%100%July 2025: 83.9% on time, 0.0% cancelledJul ’25August 2025: 96.8% on time, 0.0% cancelledAug ’25September 2025: 83.3% on time, 0.0% cancelledSep ’25October 2025: 71.4% on time, 0.0% cancelledOct ’25November 2025: 88.2% on time, 0.0% cancelledNov ’25December 2025: 60.0% on time, 0.0% cancelledDec ’25January 2026: 100.0% on time, 0.0% cancelledJan ’26May 2026: 77.8% on time, 0.0% cancelledMay ’26June 2026: 78.6% on time, 0.0% cancelledJun ’26July 2026: 80.0% on time, 3.2% cancelledJul ’26
On-time arrival rate by month. Hover a bar for exact figures.

Why this airline's flights were late

  • Late-arriving aircraft84%
  • Air traffic control & airport congestion9%
  • Airline (crew, maintenance, cleaning, fueling)7%
  • Extreme weather0%
  • Security0%

Other airlines on ONT to SEA

Full ONT to SEA comparison →
Frontier Airlines on-time record across all routes →

169 Frontier Airlines flights tracked on this route; 1 cancelled, 0 diverted.

Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. How we calculate this.