OnTimeStats

Historical on-time performance

Salt Lake City to Philadelphia

1,926 miData through May 2026Source: US DOT · BTS

Flights on SLC–PHL arrive on time 81% of the time over the last 12 months.

On-time rate81%arrived within 15 min
p90 delay25 min1 in 10 flights is worse (tail risk)
Cancelled2.1%of scheduled flights

based on 777 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

Not enough comparable data to name a most-on-time carrier — low-data carriers aren't ranked.

  • American Airlines
    On-time84%
    Medianon time
    p9020 min
    Cancel5.2%
    Flights153
  • Delta Air Lines
    On-time80%
    Medianon time
    p9025 min
    Cancel1.3%
    Flights624

Why flights run late

Delay causes

  • Airline60%
  • Weather0%
  • Air traffic (NAS)22%
  • Late aircraft17%
  • Security0%

Most delay minutes here are attributed to Airline.

When flights don't go

Why flights were cancelled

  • Airline19%
  • Weather75%
  • Air traffic (NAS)6%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 16 cancellations with a reported cause (BTS reports causes from June 2003).

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly SLC → PHL

All airlines · rolling 36 months (2023-06 .. 2026-05).

Best time of day

On-time rates are fairly even by time of day on this route — ranging from 74% to 90% on time.

  • Mornings90% on time · p90 5 min · 168 flights · limited
  • Evenings88% on time · p90 15 min · 136 flights · limited
  • Middays80% on time · p90 30 min · 1,071 flights
  • Overnights74% on time · p90 30 min · 740 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 74% to 85% on time.

  • Tuesdays85% on time · p90 20 min · 254 flights
  • Wednesdays82% on time · p90 20 min · 268 flights
  • Fridays81% on time · p90 25 min · 345 flights
  • Mondays80% on time · p90 25 min · 337 flights
  • Saturdays79% on time · p90 25 min · 261 flights
  • Thursdays76% on time · p90 35 min · 343 flights
  • Sundays74% on time · p90 30 min · 338 flights

Keep exploring

Related pages

Methodology

A flight is on time when it arrives within 15 minutes of schedule — the US DOT / BTS standard. Median and p90(the “1-in-10 bad day”) are read from the full arrival-delay distribution, never averaged across periods.

Figures cover a carrier’s own BTS-coded flights. Cells below ~200 flights are flagged as limited data. All numbers are pre-computed from public BTS On-Time Performance data.