Airport month record
BWIMAY
Baltimore/Washington International Thurgood Marshall in May 2026
- Departures
- 8,161
- Month
- May 2026
- National, same month
- 78.6%
- Carriers
- 8
Historical statistics for May 2026, not live status or a forecast for this year’s May. For today’s conditions at BWI, see live FAA status.
BWI in May lands a B+, 2 points worse than the national rate of 78.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 8,161 flights, of which Delta Air Lines flew 491 at 83.9% on time.
Delta Air Lines is the most reliable of the three carriers covered here at 83.9% on time across 491 flights.
Key figures
On time
76.7%
Arrivals under 15 minutes late, of 8,119 completed departures
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.28%
Nationally in May: 0.92%
Whole year
77.6%
BWI across all twelve months
These figures cover 8,161 departures from Baltimore/Washington International Thurgood Marshall in May 2026. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.
Against the year
May next to BWI's other months
Against BWI's own year, May ran level with the twelve-month rate of 77.6%, which makes it number eight of twelve months, best first. Cancellations were unusually low for BWI in May, at 0.28% against 1.71% across the year. Either side of it, April ran 79.9% on time and June 70.9%, so this month sits in line with its neighbours.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 8,922 | 66.2% | 92 min | 3.64% | C− |
| August 2025 | 8,381 | 78.8% | 62 min | 0.76% | B+ |
| September 2025 | 7,968 | 85.5% | 56 min | 0.18% | A+ |
| October 2025 | 8,475 | 81.4% | 49 min | 0.14% | B+ |
| November 2025 | 7,721 | 82.9% | 62 min | 1.80% | B |
| December 2025 | 7,863 | 70.4% | 54 min | 1.27% | C |
| January 2026 | 6,934 | 82.9% | 53 min | 5.61% | B− |
| February 2026 | 6,552 | 83.1% | 58 min | 3.59% | B− |
| March 2026 | 7,803 | 74.6% | 69 min | 2.58% | C |
| April 2026 | 8,041 | 79.9% | 55 min | 0.34% | B+ |
| May 2026 (this page) | 8,161 | 76.7% | 59 min | 0.28% | B+ |
| June 2026 | 8,045 | 70.9% | 63 min | 1.16% | C |
Departure window
The best time of day to leave BWI in May
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,066 flights90.0%
- 8am–11am1,748 flights88.0%
- 11am–2pm1,158 flights82.7%
- 2pm–5pm1,305 flights72.3%
- 5pm–8pm1,678 flights65.4%
- 8pm–5am1,206 flights63.3%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 63.3% on time, against 90.0% for the 5am–8am 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 8am–11am window is the busiest, with 1,748 flights scheduled in it.
Across the week, Saturday is the strongest day at 84.3% on time and Wednesday the weakest at 59.3%. 25 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at BWI in May
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 83.9% of the time; Southwest Airlines manages 75.6%. Sample sizes sit next to every figure, because a two-point gap across 6,327 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 6,327 | 75.6% | 55 min | 0.09% | B+ |
| Delta Air Lines | 491 | 83.9% | 71 min | 1.43% | B |
| United Airlines | 370 | 80.3% | 50 min | 0.54% | B+ |
| Frontier Airlinesthin sample | 339 | 73.7% | 86 min | 0.29% | C+ |
| American Airlinesthin sample | 299 | 84.2% | 132 min | 2.01% | B |
| Republic Airwaysthin sample | 159 | 85.5% | 86 min | 0.00% | A+ |
| Alaska Airlinesthin sample | 77 | 77.9% | 33 min | 0.00% | B+ |
| Envoy Airthin sample | 72 | 73.2% | 62 min | 1.39% | C |
Delta leads Southwest by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Route by route
Busiest routes out of BWI in May
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| BWI to ATL · Atlanta | 486 | 78.0% | 64 min | 0.82% | B+ |
| BWI to MCO · Orlando | 370 | 84.8% | 69 min | 0.27% | B+ |
| BWI to BOS · Bostonthin sample | 316 | 74.3% | 56 min | 0.00% | C+ |
| BWI to ORD · Chicagothin sample | 273 | 79.3% | 68 min | 0.73% | B+ |
| BWI to CLT · Charlottethin sample | 260 | 82.2% | 109 min | 0.38% | B+ |
| BWI to TPA · Tampathin sample | 255 | 76.7% | 63 min | 0.39% | B+ |
| BWI to FLL · Fort Lauderdalethin sample | 214 | 75.1% | 56 min | 0.47% | B+ |
| BWI to DEN · Denverthin sample | 208 | 78.3% | 42 min | 0.00% | B+ |
| BWI to DTW · Detroitthin sample | 206 | 80.7% | 66 min | 1.94% | B |
| BWI to MIA · Miamithin sample | 204 | 77.2% | 51 min | 0.49% | B+ |
| BWI to PVD · Providencethin sample | 167 | 71.9% | 52 min | 0.00% | C+ |
| BWI to BNA · Nashvillethin sample | 164 | 74.4% | 60 min | 0.00% | C+ |
| BWI to BUF · Buffalothin sample | 154 | 70.8% | 53 min | 0.00% | C+ |
| BWI to ALB · Albanythin sample | 154 | 80.5% | 60 min | 0.00% | B+ |
| BWI to BDL · Hartfordthin sample | 154 | 83.1% | 60 min | 0.00% | B+ |
| BWI to MHT · Manchesterthin sample | 153 | 82.4% | 48 min | 0.00% | B+ |
| BWI to RDU · Raleighthin sample | 149 | 81.9% | 63 min | 0.00% | B+ |
| BWI to LAS · Las Vegasthin sample | 149 | 84.9% | 49 min | 0.00% | B+ |
| BWI to DAL · Dallasthin sample | 144 | 66.9% | 44 min | 0.69% | C+ |
| BWI to LAX · Los Angelesthin sample | 143 | 77.5% | 63 min | 0.70% | B+ |
| BWI to MDW · Chicagothin sample | 140 | 79.3% | 56 min | 0.00% | B+ |
| BWI to RSW · Fort Myersthin sample | 136 | 80.5% | 48 min | 0.74% | B+ |
| BWI to JAX · Jacksonvillethin sample | 128 | 78.0% | 42 min | 0.78% | B+ |
| BWI to HOU · Houstonthin sample | 124 | 69.4% | 48 min | 0.00% | C+ |
| BWI to ORF · Norfolkthin sample | 124 | 77.4% | 55 min | 0.00% | B+ |
Delay causes
What held BWI up in May
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 111,000 reported delay minutes.
- 40%Late-arriving aircraft
- 36%Carrier
- 21%National Airspace System
- 3%Extreme weather
- 0%Security
40% 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 111,000 reported delay minutes here, that single category outweighs weather by 13 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 111,183 reported delay minutes.
Cancellations are rare at 0.28%, below the national 0.92% 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.
6.7% of arrivals land an hour or more late, close to the national 7.1%. 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 about an hour, which a normal layover absorbs.
What to do with this
Flying from BWI in May
For a May trip through BWI: expect 76.7% on time and 0.28% cancelled, going by May 2026. The 5am–8am window was the strongest part of the day.
Related
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.