OnTimeStats

Historical on-time performance

Islip to Baltimore

220 miData through May 2026Source: US DOT · BTS

Flights on ISP–BWI arrive on time 83% of the time over the last 12 months.

On-time rate83%arrived within 15 min
p90 delay25 min1 in 10 flights is worse (tail risk)
Cancelled1.4%of scheduled flights

based on 1,201 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • Southwest Airlines
    On-time83%
    Medianon time
    p9025 min
    Cancel1.4%
    Flights1,201

Why flights run late

Delay causes

  • Airline23%
  • Weather0%
  • Air traffic (NAS)33%
  • Late aircraft43%
  • Security0%

Most delay minutes here are attributed to Late aircraft.

When flights don't go

Why flights were cancelled

  • Airline12%
  • Weather59%
  • Air traffic (NAS)29%
  • Security0%

Most cancellations here are attributed to Weather. Shares are among 17 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 ISP → BWI

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

Best time of day

Mornings are the most reliable time of day to fly this route — 94% on time.

  • Mornings94% on time · p90 5 min · 1,402 flights
  • Middays86% on time · p90 20 min · 1,224 flights
  • Afternoons73% on time · p90 50 min · 637 flights
  • Evenings71% on time · p90 50 min · 561 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 82% to 86% on time.

  • Tuesdays86% on time · p90 15 min · 565 flights
  • Wednesdays86% on time · p90 20 min · 567 flights
  • Saturdays86% on time · p90 25 min · 453 flights
  • Thursdays85% on time · p90 25 min · 581 flights
  • Mondays84% on time · p90 25 min · 575 flights
  • Fridays83% on time · p90 30 min · 583 flights
  • Sundays82% on time · p90 30 min · 501 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.