Carrier route record
NKIAH→BWI
Spirit Airlines · Houston to Baltimore
- Flights
- 295
- Period
- September 2025 to August 2026
- Share of route
- 23%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Spirit Airlines.
Spirit on IAH to BWI lands a B, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 295 flights, with a median arrival 7 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Spirit on IAH to BWI from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.9%
Arrivals under 15 minutes late, of 289 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
2.03%
National rate is 1.89%
Whole route
77.3%
Every carrier on IAH to BWI, 1,308 flights
These figures cover 295 flights between September 2025 and August 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.
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Carrier by carrier
Spirit against every carrier on IAH to BWI
Spirit flew 295 of the 1,308 flights on IAH to BWI, about 23% of it. Its 79.9% on time is 3 points better than the route as a whole, which runs 77.3%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from SkyWest at 100.0% to Frontier at 52.1%. Two 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 2 | 100.0% | — | 0.00% | A+ |
| United Airlines | 831 | 81.3% | 60 min | 0.60% | B+ |
| Spirit Airlines (this page)thin sample | 295 | 79.9% | 59 min | 2.03% | B |
| Frontier Airlinesthin sample | 180 | 52.1% | 73 min | 7.78% | F− |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 16 points, against half a point between the best and worst carrier.
- 5am–8am208 flights80.7%
- 8am–11am—
- 11am–2pm18 flights—
- 2pm–5pm16 flights—
- 5pm–8pm46 flights65.2%
- 8pm–5am7 flights—
Scale runs 55% to 85%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 80.7% of the time, against 65.2% for the evening window. That is 16 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 208 flights scheduled in it.
Across the year
Spirit on IAH to BWI through the year
- Jul–Sep 202546 flights76.1%
- Oct–Dec 2025136 flights82.2%
- Jan–Mar 202688 flights77.4%
- Apr–Jun 202625 flights—
Scale runs 70% 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 79.9% on time across 295 flights.
Quarter by quarter Spirit on IAH to BWI held fairly steady: 76.1% in Jul–Sep 2025, 82.2% in Oct–Dec 2025 and 77.4% in Jan–Mar 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
Across the week, Wednesday is the strongest day at 89.2% on time and Monday the weakest at 68.9%, a spread of 20 points.
Arrival by arrival
How late Spirit on IAH to BWI runs when it is late
Spirit on IAH to BWI often beats the schedule: 91 of 289 completed flights, 31%, arrived 15 minutes or more early. The 58 late arrivals split 19 under half an hour, 18 between 30 and 60 minutes, and 21 an hour or more.
- 15+ min early91 flights31.5%
- Within 15 min140 flights48.4%
- 15–29 min late19 flights6.6%
- 30–59 min late18 flights6.2%
- 1–2 hours late14 flights4.8%
- 2+ hours late7 flights2.4%
Scale runs 0% to 100%.
Share of 289 completed flights by arrival against schedule.
13 of 66 late departures made up the time and arrived on time, 20% of them. Only 5 left on time and still arrived late.
The worst days
Worst days for Spirit on IAH to BWI
The latest arrival of the period was on 8 September 2025, 3 hours 28 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On four of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 8 September 2025 | 3 hours 28 minutes | Late-arriving aircraft |
| 30 December 2025 | 3 hours 5 minutes | Carrier |
| 27 January 2026 | 2 hours 44 minutes | Carrier |
| 28 January 2026 | 2 hours 30 minutes | Carrier |
| 2 March 2026 | 2 hours 23 minutes | Carrier |
Delay causes
Why Spirit runs late on this route
Carrier accounts for 69% of the 3,428 delay minutes carriers reported here, and the remaining four split what is left.
- 69%Carrier
- 13%Late-arriving aircraft
- 11%National Airspace System
- 4%Extreme weather
- 2%Security
The largest share of delay minutes, 69%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,366 of the 3,428 delay minutes reported here. The split is drawn from 3,428 reported delay minutes.
Cancellations sit at 2.03% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
7.3% of arrivals land an hour or more late, close to the national 8.3%, so 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 1,235 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.
The return leg is a different operation and performs like one: it runs 73.3% on time across 293 flights, 7 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 7 points of difference.
One caution: this is a thin sample. 295 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 BWI
Put together: treat all of this as provisional. 295 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 79.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 289 completed flights over 12 months sit behind that.
Related
Where to go next
- IAH to BWI, every carrier
- Spirit on BWI to IAH, the return leg
- United Airlines on IAH to BWI81.3%
- Frontier Airlines on IAH to BWI52.1%
- Spirit Airlines network-wide record
- George Bush Intercontinental (IAH) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- The best time of day to fly, according to 7.05 million flight records
- How to read this site: grades, sample sizes, and honest caveats
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.