Airports
Best Time to Fly
“Fly early” is folk wisdom. Enter a U.S. airport to see the real curve — the on-time departure rate for every scheduled hour of the day — from the U.S. DOT's on-time performance filings over the last 12 months.
Methodology
Every figure is computed directly from the U.S. Department of Transportation's Marketing Carrier On-Time Performance filing (Bureau of Transportation Statistics, table 236), reduced to one row per airport per scheduled departure hour per month. For the window you choose, the tool sums those monthly rows within each hour and scores the departures on their departure time.
- On-time % for an hour = departures under 15 minutes late ÷ departures with a filed departure time, for flights scheduled to leave in that clock hour. The 15-minute threshold is the federal definition of on-time (14 CFR § 234.2), used unchanged.
- Hours are the scheduled local departure hour as filed (0–23). Flights are grouped by that hour, so “7 AM” means every departure scheduled between 7:00 and 7:59 local time.
- Best and worst hour are simply the highest and lowest on-time rate among hours that clear the sample threshold, and the swing is their difference in percentage points.
Scope & limits. U.S. domestic operations of reporting marketing carriers; this tool serves Jun 2025 onward. Only airports served by reporting carriers appear, and an hour with fewer than 30 filed departures over the window is shown without a rate. These are historical base rates by hour, not a prediction for any specific future flight, and they say nothing about which airline you fly.
Last reviewed: July 2026
Frequently asked questions
Is it really better to fly early in the day?
At most airports, yes — and this tool shows by how much. The first departures of the day leave with a clean slate, while delays accumulate through the afternoon and evening as aircraft, crews and gates fall behind. But the size of the effect varies a lot by airport, and a few don't follow the pattern at all, which is exactly why this shows the real hourly curve rather than repeating the rule.
Why departure hour and not arrival hour?
Because the departure hour is the one you choose when you book. The folk rule is about picking a flight, so the tool scores each scheduled departure hour on whether those flights left on time — the decision you actually control.
What counts as "on time"?
The federal 15-minute rule: a departure is on time if it leaves the gate less than 15 minutes after its scheduled time. Fourteen minutes late still counts as on time; fifteen does not. Every figure here uses that definition unchanged (14 CFR § 234.2).
Why are some hours missing or greyed out?
Airports are quiet overnight, so some hours have few or no scheduled departures. An hour with fewer than 30 filed departures over the window is shown without a rate — too small a sample to be a statistic rather than noise — and an hour with none is skipped entirely.
Related tools
On-time departure rate by calendar month for a U.S. airport — which times of year run late, pooled across several years of the federal record.
Open tool →Airport Delay ProfileDeparture and arrival reliability at a U.S. airport, month by month, with the DOT delay-cause split — carrier, weather, National Aviation System, security, and late-arriving aircraft.
Open tool →Route Reliability CheckOn-time arrival rates, typical and worst-case delays, and cancellations for every airline on a U.S. route — from the DOT's on-time filings.
Open tool →