Carrier route record

UAIAD→CHS

United Airlines · Washington to Charleston

Flights: 463
Period: July 2025 to June 2026
Share of route: 61%
Carriers: 2

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

United on IAD to CHS earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 463 flights, with a median arrival 7 minutes early.

Set against the rest of the country, United's IAD to CHS record is 12 points better than the US average of 77.6%. That gap is worth roughly 119 fewer late arrivals for every thousand flights.

On time

89.5%

Arrivals under 15 minutes late, of 459 completed flights

Avg delay

88 min

Across delayed arrivals only, not all flights

Cancelled

0.86%

National rate is 1.81%

Whole route

86.8%

Every carrier on IAD to CHS, 761 flights

These figures cover 463 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

United against every carrier on IAD to CHS

United flew 463 of the 761 flights on IAD to CHS, most of the route. Its 89.5% on time is 3 points better than the route as a whole, which runs 86.8%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 89.5% to Republic at 82.6%. 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 IAD to CHS
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines (this page)	463	89.5%	88 min	0.86%	A+
Republic Airwaysthin sample	298	82.6%	58 min	1.68%	B

Departure window

When United runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 14 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–8am—
8am–11am246 flights93.5%
11am–2pm183 flights86.0%
2pm–5pm—
5pm–8pm4 flights—
8pm–5am30 flights80.0%

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 93.5% of the time, against 80.0% for the overnight window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 246 flights scheduled in it.

Across the year

United on IAD to CHS through the year

Jul–Sep 202573 flights95.9%
Oct–Dec 2025100 flights87.9%
Jan–Mar 2026125 flights90.2%
Apr–Jun 2026165 flights87.3%

Scale runs 80% to 100%. 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 89.5% on time across 463 flights.

Quarter by quarter United on IAD to CHS held fairly steady: 95.9% in Jul–Sep 2025, 87.9% in Oct–Dec 2025, 90.2% in Jan–Mar 2026 and 87.3% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Thursday is the strongest day at 91.3% on time and Saturday the weakest at 82.6%. 9 points is a smaller lever than departure hour, but it is free.

Delay causes

Why United runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 66% of the 4,232 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Late-arriving aircraft
66%
Carrier
19%
National Airspace System
14%
Extreme weather
1%

66% 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 4,232 reported delay minutes here, that single category outweighs weather by 66 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 4,232 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.5% on time here.

Cancellations are rare at 0.86%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.4% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 442 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.

The return leg runs 86.6% on time across 459 flights, within 3 points 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. 463 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 United on IAD to CHS

Put together: treat all of this as provisional. 463 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 89.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 459 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