Airport month record

BWIDEC

Baltimore/Washington International Thurgood Marshall in December 2025

Departures: 7,863
Month: December 2025
National, same month: 73.2%
Carriers: 9

Historical statistics for December 2025, not live status or a forecast for this year’s December. For today’s conditions at BWI, see live FAA status.

BWI in December sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 3 points worse than the national rate of 73.2%. The late ones land about 55 minutes behind schedule. That rests on 7,863 flights, of which Delta Air Lines flew 438 at 77.8% on time.

On time

70.4%

Arrivals under 15 minutes late, of 7,744 completed departures

Avg delay

54 min

Across delayed arrivals only, not all flights

Cancelled

1.27%

Nationally in December: 1.55%

Whole year

77.6%

BWI across all twelve months

These figures cover 7,863 departures from Baltimore/Washington International Thurgood Marshall in December 2025. 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

December next to BWI's other months

Against BWI's own year, December ran 7 points worse than the twelve-month rate of 77.6%, which makes it number eleven of twelve months, best first. Either side of it, November ran 82.9% on time and January 82.9%, so a trip moved by a few weeks would have landed in a better stretch.

BWI month by month
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 (this page)	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	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 December

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 21 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,057 flights80.1%
8am–11am1,941 flights77.9%
11am–2pm980 flights70.8%
2pm–5pm1,337 flights69.0%
5pm–8pm1,291 flights62.8%
8pm–5am1,257 flights59.3%

Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 59.3% on time, against 80.1% 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 1,941 flights scheduled in it.

Across the week, Wednesday is the strongest day at 83.2% on time and Friday the weakest at 55.2%. 28 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at BWI in December

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 77.8% of the time; Southwest Airlines manages 70.1%. Sample sizes sit next to every figure, because a two-point gap across 6,064 flights means less than a ten-point one.

Carriers at BWI in December 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines	6,064	70.1%	48 min	1.14%	C
Delta Air Lines	438	77.8%	66 min	3.42%	B−
United Airlinesthin sample	317	75.2%	65 min	0.32%	B+
American Airlinesthin sample	292	79.1%	73 min	0.00%	B+
Spirit Airlinesthin sample	247	66.0%	87 min	1.21%	C
Frontier Airlinesthin sample	237	61.7%	109 min	3.80%	D−
Envoy Airthin sample	123	63.6%	69 min	0.81%	D+
Republic Airwaysthin sample	80	78.2%	74 min	1.25%	B
Alaska Airlinesthin sample	60	32.2%	44 min	1.67%	F

Delta Air Lines cancels 3.4% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Route by route

Busiest routes out of BWI in December

Routes from BWI in December 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
BWI to ATL · Atlanta	433	77.7%	74 min	2.31%	B
BWI to MCO · Orlando	420	67.6%	78 min	1.43%	C
BWI to FLL · Fort Lauderdalethin sample	283	59.6%	54 min	2.12%	D
BWI to BOS · Bostonthin sample	274	72.9%	54 min	1.46%	C
BWI to CLT · Charlottethin sample	248	76.2%	77 min	0.00%	B+
BWI to DEN · Denverthin sample	243	61.9%	45 min	0.82%	D+
BWI to MIA · Miamithin sample	218	68.7%	54 min	1.83%	C
BWI to TPA · Tampathin sample	210	70.2%	64 min	1.90%	C
BWI to ORD · Chicagothin sample	205	62.0%	77 min	1.95%	D
BWI to DAL · Dallasthin sample	165	63.2%	45 min	1.21%	D
BWI to DTW · Detroitthin sample	165	70.6%	58 min	3.03%	C−
BWI to RDU · Raleighthin sample	161	79.7%	43 min	1.86%	B
BWI to PVD · Providencethin sample	156	73.5%	45 min	0.64%	C+
BWI to MHT · Manchesterthin sample	153	77.6%	47 min	0.00%	B+
BWI to BUF · Buffalothin sample	152	68.3%	45 min	3.95%	C−
BWI to ALB · Albanythin sample	152	74.7%	45 min	1.32%	C
BWI to LAS · Las Vegasthin sample	152	70.7%	45 min	0.66%	C+
BWI to BDL · Hartfordthin sample	148	76.2%	42 min	0.68%	B+
BWI to MDW · Chicagothin sample	138	65.2%	53 min	1.45%	C
BWI to JAX · Jacksonvillethin sample	134	72.9%	39 min	0.75%	C+
BWI to RSW · Fort Myersthin sample	134	64.9%	55 min	2.24%	D
BWI to HOU · Houstonthin sample	133	74.4%	54 min	3.01%	C−
BWI to BNA · Nashvillethin sample	131	78.3%	49 min	0.76%	B+
BWI to LAX · Los Angelesthin sample	123	66.4%	39 min	0.81%	C+
BWI to ORF · Norfolkthin sample	122	75.4%	47 min	0.00%	B+

Delay causes

What held BWI up in December

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 124,000 reported delay minutes.

Late-arriving aircraft
37%
Carrier
36%
National Airspace System
24%
Extreme weather
2%
Security
1%

37% 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 124,000 reported delay minutes here, that single category outweighs weather by 18 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 123,837 reported delay minutes.

Cancellations sit at 1.27% against a national 1.55%, which is ordinary. Diversions add another 0.24%.

8.2% of arrivals land an hour or more late, close to the national 10.0%. 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 55 minutes, which a normal layover absorbs.

What to do with this

Flying from BWI in December

For a December trip through BWI: plan on this being one of the airport's harder months. The 5am–8am departures held up best at 80.1% on time, and with 8.2% of arrivals an hour or more late, a connection here deserves more slack than the same trip in September would.

Baltimore/Washington International Thurgood Marshall (BWI), the whole year
BWI in July66.2%
BWI in August78.8%
BWI in September85.5%
BWI in October81.4%
BWI in November82.9%
BWI in January82.9%
BWI in February83.1%
BWI in March74.6%
BWI in April79.9%
BWI in May76.7%
BWI in June70.9%

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.

Key figures