OnTimeStats

Historical on-time performance

Houston to Greenville

838 miData through Dec 2025Source: US DOT · BTS

Flights on IAH–GSP arrive on time 72% of the time over the last 12 months.

On-time rate72%arrived within 15 min
p90 delay35 min1 in 10 flights is worse (tail risk)
Cancelled1.1%of scheduled flights

based on 92 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).

By airline

How each carrier compares

  • United Airlines
    On-time72%
    Medianon time
    p9035 min
    Cancel1.1%
    Flights92

Why flights run late

Delay causes

  • Airline81%
  • Weather3%
  • Air traffic (NAS)2%
  • Late aircraft14%
  • Security0%

Most delay minutes here are attributed to Airline.

Over time

On-time trend

By season

On-time rate by month

When to fly

Best time to fly IAH → GSP

All airlines · rolling 36 months (2023-01 .. 2025-12).

Best time of day

On-time rates are fairly even by time of day on this route — ranging from 67% to 73% on time.

  • Overnights73% on time · p90 70 min · 139 flights · limited
  • Evenings67% on time · p90 70 min · 660 flights

Best day of week

On-time rates are fairly even by day on this route — ranging from 66% to 73% on time.

  • Wednesdays73% on time · p90 60 min · 118 flights · limited
  • Thursdays69% on time · p90 65 min · 120 flights · limited
  • Saturdays69% on time · p90 60 min · 113 flights · limited
  • Sundays68% on time · p90 65 min · 123 flights · limited
  • Tuesdays68% on time · p90 70 min · 123 flights · limited
  • Mondays66% on time · p90 75 min · 122 flights · limited
  • Fridays66% on time · p90 85 min · 119 flights · limited
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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.