Airport month record
IADMAR
Washington Dulles International in March 2026
- Departures
- 4,983
- Month
- March 2026
- National, same month
- 75.7%
- Carriers
- 10
Historical statistics for March 2026, not live status or a forecast for this year’s March. For today’s conditions at IAD, see live FAA status.
IAD in March lands a B, 4 points better than the national rate of 75.7%. About one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 4,983 flights, of which United Airlines flew 3,306 at 82.4% on time.
Key figures
On time
79.6%
Arrivals under 15 minutes late, of 4,876 completed departures
Avg delay
92 min
Across delayed arrivals only, not all flights
Cancelled
1.81%
Nationally in March: 2.90%
Whole year
81.1%
IAD across all twelve months
These figures cover 4,983 departures from Washington Dulles International in March 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
March next to IAD's other months
Against IAD's own year, March ran 2 points worse than the twelve-month rate of 81.1%, which makes it number nine of twelve months, best first. Either side of it, February ran 83.3% on time and April 87.2%, so a trip moved by a few weeks would have landed in a better stretch.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 5,248 | 69.5% | 102 min | 2.88% | C |
| August 2025 | 5,201 | 81.0% | 70 min | 0.79% | B+ |
| September 2025 | 4,815 | 86.8% | 67 min | 0.27% | A+ |
| October 2025 | 4,854 | 84.6% | 64 min | 0.27% | B+ |
| November 2025 | 4,589 | 81.8% | 71 min | 1.46% | B |
| December 2025 | 4,676 | 74.8% | 69 min | 0.71% | C+ |
| January 2026 | 4,248 | 83.0% | 82 min | 5.65% | B− |
| February 2026 | 4,037 | 83.3% | 74 min | 1.34% | B |
| March 2026 (this page) | 4,983 | 79.6% | 92 min | 1.81% | B |
| April 2026 | 4,843 | 87.2% | 71 min | 0.31% | A+ |
| May 2026 | 5,474 | 84.1% | 78 min | 0.57% | B+ |
| June 2026 | 5,053 | 78.1% | 85 min | 0.93% | B+ |
Departure window
The best time of day to leave IAD in March
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am439 flights80.8%
- 8am–11am1,230 flights90.8%
- 11am–2pm919 flights79.2%
- 2pm–5pm359 flights79.5%
- 5pm–8pm1,363 flights72.1%
- 8pm–5am673 flights73.8%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 90.8% of the time, against 72.1% for the evening window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 1,363 flights scheduled in it.
Across the week, Tuesday is the strongest day at 83.5% on time and Friday the weakest at 71.2%. 12 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at IAD in March
The choice of carrier is not cosmetic here. United Airlines arrives on time 82.4% of the time; Republic Airways manages 74.3%. Sample sizes sit next to every figure, because a two-point gap across 735 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 3,306 | 82.4% | 91 min | 0.85% | B+ |
| Republic Airways | 735 | 74.3% | 76 min | 3.81% | C− |
| Delta Air Linesthin sample | 244 | 76.5% | 112 min | 3.69% | B− |
| SkyWest Airlinesthin sample | 214 | 67.0% | 153 min | 6.07% | C− |
| Southwest Airlinesthin sample | 93 | 76.1% | 78 min | 1.08% | B |
| American Airlinesthin sample | 93 | 83.1% | 144 min | 3.23% | B− |
| Alaska Airlinesthin sample | 86 | 61.6% | 52 min | 0.00% | D+ |
| PSA Airlinesthin sample | 85 | 83.5% | 84 min | 7.06% | B− |
| Frontier Airlinesthin sample | 84 | 69.5% | 77 min | 2.38% | C |
| Allegiant Airthin sample | 43 | 74.4% | 69 min | 0.00% | C+ |
Republic Airways cancels 3.8% 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 IAD in March
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| IAD to ATL · Atlantathin sample | 305 | 78.9% | 124 min | 2.30% | B |
| IAD to DEN · Denverthin sample | 300 | 80.8% | 75 min | 0.67% | B+ |
| IAD to SFO · San Franciscothin sample | 209 | 87.8% | 96 min | 1.91% | A |
| IAD to MCO · Orlandothin sample | 197 | 85.3% | 75 min | 2.03% | A |
| IAD to LAX · Los Angelesthin sample | 184 | 84.8% | 67 min | 0.00% | B+ |
| IAD to CLT · Charlottethin sample | 179 | 84.1% | 83 min | 5.03% | B− |
| IAD to DFW · Dallas-Fort Worththin sample | 149 | 79.9% | 125 min | 2.01% | B |
| IAD to ORD · Chicagothin sample | 148 | 77.5% | 106 min | 2.70% | B |
| IAD to IAH · Houstonthin sample | 144 | 84.5% | 121 min | 1.39% | B |
| IAD to TPA · Tampathin sample | 128 | 81.1% | 116 min | 0.78% | B+ |
| IAD to DTW · Detroitthin sample | 128 | 66.7% | 110 min | 3.12% | C− |
| IAD to EWR · Newarkthin sample | 124 | 76.2% | 94 min | 1.61% | B |
| IAD to BOS · Bostonthin sample | 119 | 80.3% | 67 min | 1.68% | B |
| IAD to SAN · San Diegothin sample | 117 | 86.2% | 71 min | 0.85% | A+ |
| IAD to PHX · Phoenixthin sample | 117 | 83.6% | 91 min | 0.85% | B+ |
| IAD to SEA · Seattlethin sample | 117 | 54.4% | 55 min | 0.85% | F+ |
| IAD to CMH · Columbusthin sample | 117 | 72.4% | 71 min | 0.85% | C+ |
| IAD to RDU · Raleighthin sample | 115 | 76.3% | 85 min | 0.87% | B+ |
| IAD to PIT · Pittsburghthin sample | 115 | 73.7% | 98 min | 0.87% | C+ |
| IAD to BDL · Hartfordthin sample | 111 | 82.1% | 70 min | 3.60% | B− |
| IAD to LGA · New Yorkthin sample | 95 | 66.7% | 81 min | 13.68% | C− |
| IAD to JAX · Jacksonvillethin sample | 94 | 83.0% | 76 min | 0.00% | B+ |
| IAD to AUS · Austinthin sample | 92 | 84.8% | 74 min | 0.00% | B+ |
| IAD to CHS · Charlestonthin sample | 92 | 83.5% | 63 min | 1.09% | B |
| IAD to IND · Indianapolisthin sample | 92 | 72.8% | 135 min | 0.00% | C+ |
Delay causes
What held IAD up in March
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 91,000 reported delay minutes.
- 34%Late-arriving aircraft
- 33%Carrier
- 29%National Airspace System
- 5%Extreme weather
- 0%Security
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 90.8% on time here. The split is drawn from 91,453 reported delay minutes.
Cancellations sit at 1.81% against a national 2.90%, which is ordinary. Diversions add another 0.34%.
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.2% of arrivals land a full hour or more behind schedule, against 9.5% 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.
What to do with this
Flying from IAD in March
For a March trip through IAD: expect 79.6% on time and 1.81% cancelled, going by March 2026. The 8am–11am window was the strongest part of the day.
Related
Where to go next
- Washington Dulles International (IAD), the whole year
- IAD in July69.5%
- IAD in August81.0%
- IAD in September86.8%
- IAD in October84.6%
- IAD in November81.8%
- IAD in December74.8%
- IAD in January83.0%
- IAD in February83.3%
- IAD in April87.2%
- IAD in May84.1%
- IAD in June78.1%
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.