Route reliability record
EWR→STL
Newark to St. Louis
- Flights
- 1,074
- Period
- July 2025 to June 2026
- Distance
- 872 mi
- Carriers
- 2
This route carries a cancellation problem, not just a delay problem: 5.0% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, more than four flights in five arrive on time, worth a B− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,074 EWR to STL flights, with a median arrival 14 minutes early.
Best time to fly EWR to STL: a 8am–11am departure, ideally on a Friday. Flights in that window arrived on time 89.7% of the time and Friday flights 88.1%, against 84.6% for the route overall.
Set against the rest of the country, this route's record is 7 points better than the US average of 77.6%. That gap is worth roughly 70 fewer late arrivals for every thousand flights.
Key figures
On time
84.6%
Arrivals under 15 minutes late, of 1,018 completed flights
Avg delay
69 min
Across delayed arrivals only, not all flights
Cancelled
5.03%
National rate is 1.81%
Best carrier
Republic
86.4% on time across 946 flights
These figures cover 1,074 flights between July 2025 and June 2026. The median arrival is 14 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
Which airline is most reliable on EWR to STL
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airways | 946 | 86.4% | 69 min | 5.60% | A− |
| United Airlinesthin sample | 128 | 71.7% | 71 min | 0.78% | C+ |
Flight by flight
Flights on EWR to STL
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly Newark to St. Louis
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 2 of the top 3 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. EWR → STLNewark to St. Louis | Republic Airways | 81.6% | 86.4% | 5.60% | 8am–11am, Sun | YX 3630 09:00 |
| 2. LGA → STLNew York to St. Louis | Republic Airways | 73.5% | 77.6% | 5.22% | 5am–8am, Wed | — |
| 3. LGA → STLNew York to St. Louis | Southwest Airlines | 71.5% | 73.7% | 3.02% | 5am–8am, Fri | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
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–11am361 flights89.7%
- 11am–2pm—
- 2pm–5pm331 flights88.6%
- 5pm–8pm19 flights—
- 8pm–5am363 flights75.7%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 89.7% of the time, against 75.7% 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 8pm–5am window is the busiest, with 363 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 28 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 69.0% on time, against 96.5% in April. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. September was the busiest month here, with 106 flights.
Across the week, Friday is the strongest day at 88.1% on time and Saturday the weakest at 80.0%. 8 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 11,000 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.
- 43%Late-arriving aircraft
- 27%Carrier
- 20%National Airspace System
- 9%Extreme weather
43% 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 11,000 reported delay minutes here, that single category outweighs weather by 5 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 10,902 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 89.7% on time here.
Cancellations run at 5.03%, 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 actually costs
5.9% 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 a little over an hour, which a normal layover absorbs.
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 81.3% on time across 1,075 flights, 3 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 3 points of difference.
One caution: this is a thin sample. 1,074 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.
Work out the risk of missing a connection in STL after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 5.03% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 1,018 completed flights over 12 months sit behind that.
Common questions
EWR to STL questions
How often is EWR to STL delayed?
Roughly one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 15.4% of the 1,074 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is EWR to STL compared with the rest of the country?
84.6% of flights arrive on time here against a national 77.6%, a difference of 7 points in its favour. That is worth a B− on this site's grading scale.
What time of day has the fewest delays on EWR to STL?
The 8am–11am departure window is the strongest at 89.7% on time. The 8pm–5am window is the weakest at 75.7%, 14 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on EWR to STL?
December is the weakest month at 69.0% on time, compared with 96.5% in April. Across the year that is 28 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- STL to EWR — the return legseparate record
- Newark Liberty International (EWR) delay statistics
- St. Louis Lambert International (STL) delay statistics
- Republic Airways on EWR to STL86.4%
- United Airlines on EWR to STL71.7%
- EWR to MCO, a related route77.1%
- ATL to STL, a related route82.4%
- EWR to ATL, a related route77.6%
- Republic Airways on-time record86.4%
- United Airlines on-time record71.7%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. EWR to STL and STL to EWR are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed EWR to STL’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
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.