Carrier route record

UAEWR→STL

United Airlines · Newark to St. Louis

Flights: 128
Period: July 2025 to June 2026
Share of route: 12%
Carriers: 2

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

United on EWR to STL sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 128 flights, with a median arrival 2 minutes early.

The national on-time rate over the same period is 77.6%, so United on EWR to STL runs 6 points behind the country as a whole. Across a thousand flights that is about 59 extra late arrivals.

On time

71.7%

Arrivals under 15 minutes late, of 127 completed flights

Avg delay

71 min

Across delayed arrivals only, not all flights

Cancelled

0.78%

National rate is 1.81%

Whole route

84.6%

Every carrier on EWR to STL, 1,074 flights

These figures cover 128 flights between July 2025 and June 2026. Beyond the headline rate, 14.2% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

United against every carrier on EWR to STL

United flew 128 of the 1,074 flights on EWR to STL, about 12% of it. Its 71.7% on time is 13 points worse than the route as a whole, which runs 84.6%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Republic at 86.4% to United at 71.7%.

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 EWR to STL
Airline	Flights	On time	Avg delay	Cancelled	Grade
Republic Airways	946	86.4%	69 min	5.60%	A−
United Airlines (this page)thin sample	128	71.7%	71 min	0.78%	C+

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 17 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–11am45 flights77.8%
11am–2pm—
2pm–5pm26 flights—
5pm–8pm—
8pm–5am57 flights60.7%

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 60.7% on time, against 77.8% for the 8am–11am 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 8pm–5am window is the busiest, with 57 flights scheduled in it.

Across the year

United on EWR to STL through the year

Jul–Sep 20255 flights—
Oct–Dec 202578 flights76.6%
Jan–Mar 20264 flights—
Apr–Jun 202641 flights61.0%

Scale runs 55% to 80%. 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 71.7% on time across 128 flights.

Split by quarter, United on EWR to STL logged 5 flights in Jul–Sep 2025, 78 flights in Oct–Dec 2025, 4 flights in Jan–Mar 2026 and 41 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 71.7% annual figure is the one to use.

Delay causes

Why United 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 2,570 reported delay minutes.

Late-arriving aircraft
38%
Carrier
34%
National Airspace System
21%
Extreme weather
7%

38% 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 2,570 reported delay minutes here, that single category outweighs weather by 6 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 2,570 reported delay minutes.

The largest share of delay minutes, 34%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 878 of the 2,570 delay minutes reported here.

Cancellations are rare at 0.78%, 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 14.2% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

The 872 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 is a different operation and performs like one: it runs 65.4% on time across 127 flights, 6 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 6 points of difference.

One caution: this is a thin sample. 128 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 EWR to STL

Put together: treat all of this as provisional. 128 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 71.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 127 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