Route profile
IAH→BWI
Flight reliability, delays and best times to fly from Houston to Baltimore, 1,235 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 37% of comparable major US routes (4,598 compared)
Calculated from 3,630 flights. How this is calculated · What counts as on time
IAH → BWI arrives on time 77.3% of the time; the return trip, BWI → IAH, arrives on time 79.6% of the time, a 2.3-point gap between the two directions of the same city pair.
IAH → BWI spends 26.0 minutes on the ground on a 1,235-mile trip: 19.8 minutes from pushback to wheels-up at IAH and 6.2 minutes from touchdown to gate at BWI.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Reliability here swings unusually widely by season, a wider month-to-month spread than 99% of 3,357 comparable routes.
88.1% on time in a typical February, against 58.3% in July.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 3,357 in the comparison.
What sets this route apart
Where IAH to BWI differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
IAH to BWI struggles most at 5 AM: 79.8% of its flights scheduled then arrive on time, 11.5 points behind the 91.3% on routes of similar length at the same hour. Against all other routes the gap is 12.4 points.
IAH to BWI is at its best against routes of similar length for flights scheduled at 12 PM: 82.4% arrive on time, 4.5 points ahead of the 77.9% those routes manage at that hour.
In July, IAH to BWI runs 10.4 points below routes of similar length, 58.3% on time to 68.7%. Against all other routes the gap is 11.4 points.
February is kinder to IAH to BWI than to routes of similar length: 88.1% on time against 80.4%, 7.7 points better. Against all other routes the gap is 6.7 points.
Spirit Airlines does better on IAH to BWI than on its routes of similar length: 78.8% on time here, 74.0% there, 4.8 points apart. Against all other routes the gap is 3.5 points.
IAH to BWI against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 5 AM departures | 79.8% | routes of similar length | 91.3% | −11.5 pts | 163 here, 63,309 there |
| Hour: 12 PM departures | 82.4% | routes of similar length | 77.9% | +4.5 pts | 698 here, 125,719 there |
| Month: July | 58.3% | routes of similar length | 68.7% | −10.4 pts | 374 here, 206,516 there |
| Month: February | 88.1% | routes of similar length | 80.4% | +7.7 pts | 244 here, 145,171 there |
| Airline: Spirit Airlines | 78.8% | routes of similar length | 74.0% | +4.8 pts | 1,309 here, 131,319 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,235 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
Why IAH → BWI flights are cancelled
July 2023 – July 2026
IAH → BWI cancelled 59 of 3,630 scheduled flights — about 1 in every 62. The reason filed most often was extreme weather, 50.8% of the cancellations coded on this route — about 1 in every 121 scheduled flights.
Share of cancellations
Of 59 cancelled departures carrying a reason code.
What each reason means
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
30 cancellations, 50.8% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
27 cancellations, 45.8% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
2 cancellations, 3.4% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. With only one or two carriers on the route, the split mostly reflects how they file. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
59 coded cancellations were recorded on IAH → BWI; the section appears from 50.
When it goes wrong
July 2023 – July 2026
49 min late
against a median of 5 min early
Percentiles over 3,630 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at BWI after arriving from IAH.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 38% | Likely to miss |
| 45 min | 22% | High risk |
| 60 min | 15% | Some risk |
| 90 min | 8.1% | Some risk |
| 120 min | 5.0% | Some risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.63% of the time and diverts 0.25% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,562 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 49 minutes late (90th-percentile gate arrival delay), over 3,630 operations.
Any other layover length: connection checker.
Best time to fly
IAH → BWI flights departing 5–9 AM arrived on time 85.1% of the time, against 65.1% for 3–6 PM departures, a gap of 20.0 percentage points.
By departure window
By departure hour
- 12 AM to 4 AM: too few flights to score
- 5 AM: 79.8% on time from 168 flights
- 6 AM: 86.4% on time from 252 flights
- 7 AM: 85.1% on time from 359 flights
- 8 AM: 88.9% on time from 137 flights
- 9 AM: 87.5% on time from 185 flights
- 10 AM: too few flights to score
- 11 AM: 81.0% on time from 140 flights
- 12 PM: 82.4% on time from 705 flights
- 1 PM to 3 PM: too few flights to score
- 4 PM: 47.5% on time from 126 flights
- 5 PM: too few flights to score
- 6 PM: 70.9% on time from 1,130 flights
- 7 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why IAH → BWI runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for IAH → BWI. Only delays of 15 minutes or more are attributed. What the five causes mean
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 2,149 | 78.0% | 1.49% | -5 min | 8.1% |
| Spirit Airlines | 1,330 | 78.8% | 1.43% | -6 min | 7.6% |
United Airlines flew 61.8% of the 3,479 flights listed.
Carriers on this route performed within a couple of percentage points of each other.
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Sunday the least, a gap of 8.6 percentage points.
By month
- Jan: 84.2%
- Feb: 88.1%
- Mar: 77.6%
- Apr: 80.8%
- May: 71.3%
- Jun: 68.0%
- Jul: 58.3%
- Aug: 72.9%
- Sep: 85.1%
- Oct: 83.4%
- Nov: 87.4%
- Dec: 77.9%
July is historically the weakest month and February the strongest, a spread of 29.8 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: too few flights to score (77)
- August 2023: too few flights to score (81)
- September 2023: too few flights to score (82)
- October 2023: too few flights to score (87)
- November 2023: too few flights to score (89)
- December 2023: too few flights to score (74)
- January 2024: too few flights to score (72)
- February 2024: too few flights to score (65)
- March 2024: too few flights to score (61)
- April 2024: too few flights to score (102)
- May 2024: too few flights to score (109)
- June 2024: too few flights to score (115)
- July 2024: too few flights to score (97)
- August 2024: 74.1% from 122 flights
- September 2024: too few flights to score (108)
- October 2024: too few flights to score (109)
- November 2024: too few flights to score (107)
- December 2024: too few flights to score (112)
- January 2025: too few flights to score (111)
- February 2025: too few flights to score (79)
- March 2025: too few flights to score (66)
- April 2025: too few flights to score (90)
- May 2025: too few flights to score (103)
- June 2025: too few flights to score (95)
- July 2025: too few flights to score (106)
- August 2025: too few flights to score (99)
- September 2025: too few flights to score (106)
- October 2025: too few flights to score (107)
- November 2025: 84.4% from 122 flights
- December 2025: too few flights to score (105)
- January 2026: too few flights to score (119)
- February 2026: too few flights to score (103)
- March 2026: too few flights to score (115)
- April 2026: 81.7% from 121 flights
- May 2026: too few flights to score (106)
- June 2026: too few flights to score (102)
- July 2026: too few flights to score (106)
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 76.4% against 78.1% in the 12 months before — declining by 1.7 percentage points.
Data and methodology
Calculated by FlyerIntel from 3,630 IAH → BWI flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed