Historical on-time performance
Washington to Johnstown
120 miData through May 2026Source: US DOT · BTS
Flights on IAD–JST arrive on time 69% of the time over the last 12 months.
On-time rate69%arrived within 15 min
p90 delay100 min1 in 10 flights is worse (tail risk)
Cancelled4.0%of scheduled flights
based on 275 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- SkyWest AirlinesOn-time69%Medianon timep90100 minCancel4.0%Flights275
Why flights run late
Delay causes
- Airline28%
- Weather31%
- Air traffic (NAS)3%
- Late aircraft38%
- Security0%
Most delay minutes here are attributed to Late aircraft.
When flights don't go
Why flights were cancelled
- Airline9%
- Weather91%
- Air traffic (NAS)0%
- Security0%
Most cancellations here are attributed to Weather. Shares are among 11 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 IAD → JST
All airlines · rolling 36 months (2023-06 .. 2026-05).
Best day of week
On-time rates are fairly even by day on this route — ranging from 72% to 78% on time.
- Fridays78% on time · p90 60 min · 157 flights · limited
- Saturdays78% on time · p90 40 min · 148 flights · limited
- Tuesdays78% on time · p90 85 min · 148 flights · limited
- Mondays77% on time · p90 70 min · 156 flights · limited
- Thursdays76% on time · p90 85 min · 156 flights · limited
- Sundays75% on time · p90 55 min · 157 flights · limited
- Wednesdays72% on time · p90 75 min · 156 flights · limited
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