Carrier route record
NKIAH→EWR
Spirit Airlines · Houston to Newark
- Flights
- 266
- Period
- July 2025 to June 2026
- Share of route
- 7%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Spirit Airlines.
Spirit on IAH to EWR 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 266 flights, with a median arrival 9 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Spirit on IAH to EWR from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.5%
Arrivals under 15 minutes late, of 249 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
6.39%
National rate is 1.81%
Whole route
74.6%
Every carrier on IAH to EWR, 3,800 flights
These figures cover 266 flights between July 2025 and June 2026. Beyond the headline rate, 9.6% 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
Spirit against every carrier on IAH to EWR
Spirit flew 266 of the 3,800 flights on IAH to EWR, about 7% of it. Its 75.5% on time is about level with the route as a whole at 74.6%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Spirit at 75.5% to United at 74.5%.
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 |
|---|---|---|---|---|---|
| Spirit Airlines (this page)thin sample | 266 | 75.5% | 65 min | 6.39% | B− |
| United Airlines | 3,534 | 74.5% | 72 min | 1.56% | C |
Departure window
When Spirit runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 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–8am199 flights80.0%
- 8am–11am17 flights—
- 11am–2pm36 flights60.6%
- 2pm–5pm13 flights—
- 5pm–8pm1 flights—
- 8pm–5am—
Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 60.6% on time against 80.0% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5am–8am window is the busiest, with 199 flights scheduled in it.
Across the year
Spirit on IAH to EWR through the year
- Jul–Sep 202585 flights70.7%
- Oct–Dec 202580 flights86.1%
- Jan–Mar 202673 flights73.0%
- Apr–Jun 202628 flights—
Scale runs 60% to 90%. 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 75.5% on time across 266 flights.
Spirit on IAH to EWR did not run the same all year. Its best quarter was Oct–Dec 2025 at 86.1% on time and its weakest Jul–Sep 2025 at 70.7%, a swing of 15 points on roughly 89 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Friday is the strongest day at 79.1% on time and Saturday the weakest at 66.7%. 12 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Spirit runs late on this route
One category carries most of the weight here. Carrier accounts for 53% of the 3,939 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.
- 53%Carrier
- 40%National Airspace System
- 5%Late-arriving aircraft
- 1%Security
- 1%Extreme weather
The largest share of delay minutes, 53%, 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 2,105 of the 3,939 delay minutes reported here. The split is drawn from 3,939 reported delay minutes.
40% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,570 minutes out of 3,939, against a national NAS share of 21%.
Cancellations run at 6.39%, against 1.81% nationally. That is about one flight in fifteen 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.6% 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 1,400 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 67.8% on time across 264 flights, 8 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 8 points of difference.
One caution: this is a thin sample. 266 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 Spirit on IAH to EWR
Put together: the delay figures matter less here than the 6.39% 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. 249 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to EWR, every carrier
- Spirit on EWR to IAH, the return leg
- United Airlines on IAH to EWR74.5%
- Spirit Airlines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- Newark Liberty International (EWR) delay statistics
- The US routes with the most cancellations
- What a cancellation rate actually tells you (and what it hides)
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.