Carrier route record

YXIAH→DCA

Republic Airways · Houston to Washington

Flights: 513
Period: July 2025 to June 2026
Share of route: 16%
Carriers: 3

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Republic Airways.

Republic on IAH to DCA sits in the middle of the pack with a B−. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 513 flights, with a median arrival 7 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Republic on IAH to DCA from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

75.9%

Arrivals under 15 minutes late, of 486 completed flights

Avg delay

64 min

Across delayed arrivals only, not all flights

Cancelled

4.87%

National rate is 1.81%

Whole route

74.8%

Every carrier on IAH to DCA, 3,202 flights

These figures cover 513 flights between July 2025 and June 2026. The median arrival is 7 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Republic against every carrier on IAH to DCA

Republic flew 513 of the 3,202 flights on IAH to DCA, about 16% of it. Its 75.9% on time is about level with the route as a whole at 74.8%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Republic at 75.9% to PSA at 69.0%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on IAH to DCA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Republic Airways (this page)	513	75.9%	64 min	4.87%	B−
United Airlines	2,413	75.2%	70 min	0.79%	B+
PSA Airlinesthin sample	276	69.0%	109 min	5.07%	C−

Departure window

When Republic runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 28 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am201 flights87.6%
8am–11am117 flights78.9%
11am–2pm17 flights—
2pm–5pm1 flights—
5pm–8pm177 flights59.9%
8pm–5am—

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 59.9% on time, against 87.6% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 201 flights scheduled in it.

Across the year

Republic on IAH to DCA through the year

Jul–Sep 202570 flights80.0%
Oct–Dec 2025235 flights74.7%
Jan–Mar 2026196 flights76.5%
Apr–Jun 202612 flights—

Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 75.9% on time across 513 flights.

Quarter by quarter Republic on IAH to DCA held fairly steady: 80.0% in Jul–Sep 2025, 74.7% in Oct–Dec 2025 and 76.5% in Jan–Mar 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Saturday is the strongest day at 90.3% on time and Sunday the weakest at 62.9%. 27 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Republic runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,490 reported delay minutes.

Late-arriving aircraft
40%
Carrier
31%
National Airspace System
28%
Extreme weather
1%

40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 7,490 reported delay minutes here, that single category outweighs weather by 40 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 7,490 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.6% on time here.

Cancellations run at 4.87%, against 1.81% nationally. That is about one flight in twenty cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

7.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

The 1,208 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg runs 75.7% on time across 511 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 513 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Republic on IAH to DCA

Put together: the delay figures matter less here than the 4.87% cancellation rate. A late arrival costs you about an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 486 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures