Airport month record
IADJAN
Washington Dulles International in January 2026
- Departures
- 4,248
- Month
- January 2026
- National, same month
- 79.2%
- Carriers
- 9
Historical statistics for January 2026, not live status or a forecast for this year’s January. For today’s conditions at IAD, see live FAA status.
IAD in January carries a cancellation problem, not just a delay problem: 5.7% of scheduled flights never operate, against 4.7% nationally. Of the ones that do fly, more than four flights in five arrive on time, worth a B− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 4,248 flights, of which Republic Airways flew 628 at 86.7% on time.
Key figures
On time
83.0%
Arrivals under 15 minutes late, of 4,000 completed departures
Avg delay
82 min
Across delayed arrivals only, not all flights
Cancelled
5.65%
Nationally in January: 4.71%
Whole year
81.1%
IAD across all twelve months
These figures cover 4,248 departures from Washington Dulles International in January 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
January next to IAD's other months
Against IAD's own year, January ran 2 points better than the twelve-month rate of 81.1%, which makes it number six of twelve months, best first. Cancellations are where January stands out: 5.65% of scheduled departures were called off, 4.1 times the airport's rate across the year. Either side of it, December ran 74.8% on time and February 83.3%, so a trip moved by a few weeks would have landed in a worse 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 (this page) | 4,248 | 83.0% | 82 min | 5.65% | B− |
| February 2026 | 4,037 | 83.3% | 74 min | 1.34% | B |
| March 2026 | 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 January
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 4,248 flights.
- 5am–8am353 flights80.6%
- 8am–11am986 flights86.2%
- 11am–2pm897 flights85.6%
- 2pm–5pm260 flights82.3%
- 5pm–8pm1,331 flights79.5%
- 8pm–5am421 flights84.4%
Scale runs 70% to 90%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 86.2% on time for the 8am–11am window against 79.5% for 5pm–8pm. Worth taking if the schedule allows, not worth an extra connection. The 5pm–8pm window is the busiest, with 1,331 flights scheduled in it.
Across the week, Wednesday is the strongest day at 88.1% on time and Monday the weakest at 72.3%. 16 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at IAD in January
The two carriers here are closely matched: 3 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,728 | 83.8% | 75 min | 4.80% | B− |
| Republic Airways | 628 | 86.7% | 70 min | 6.21% | A− |
| Delta Air Linesthin sample | 222 | 79.1% | 128 min | 7.21% | B− |
| SkyWest Airlinesthin sample | 188 | 69.5% | 138 min | 9.57% | C− |
| Frontier Airlinesthin sample | 113 | 74.5% | 97 min | 6.19% | C− |
| PSA Airlinesthin sample | 98 | 85.2% | 67 min | 10.20% | A− |
| Southwest Airlinesthin sample | 92 | 87.5% | 31 min | 4.35% | A− |
| American Airlinesthin sample | 86 | 88.0% | 51 min | 12.79% | A− |
| Alaska Airlinesthin sample | 68 | 69.7% | 50 min | 2.94% | C |
Republic Airways cancels 6.2% 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 January
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| IAD to ATL · Atlantathin sample | 281 | 82.2% | 106 min | 6.05% | B− |
| IAD to DEN · Denverthin sample | 280 | 87.0% | 81 min | 3.93% | A− |
| IAD to SFO · San Franciscothin sample | 209 | 78.3% | 115 min | 4.78% | B− |
| IAD to CLT · Charlottethin sample | 197 | 84.3% | 75 min | 9.64% | B− |
| IAD to MCO · Orlandothin sample | 186 | 82.0% | 66 min | 3.76% | B− |
| IAD to LAX · Los Angelesthin sample | 174 | 77.0% | 65 min | 4.60% | B− |
| IAD to DFW · Dallas-Fort Worththin sample | 138 | 86.2% | 91 min | 10.87% | A− |
| IAD to ORD · Chicagothin sample | 129 | 72.8% | 48 min | 3.10% | C− |
| IAD to IAH · Houstonthin sample | 129 | 89.5% | 84 min | 3.88% | A− |
| IAD to EWR · Newarkthin sample | 124 | 82.8% | 54 min | 6.45% | B− |
| IAD to PIT · Pittsburghthin sample | 113 | 88.8% | 90 min | 5.31% | A− |
| IAD to SAN · San Diegothin sample | 112 | 83.2% | 58 min | 3.57% | B− |
| IAD to BOS · Bostonthin sample | 111 | 87.5% | 104 min | 6.31% | A− |
| IAD to TPA · Tampathin sample | 109 | 86.7% | 53 min | 3.67% | A− |
| IAD to SEA · Seattlethin sample | 103 | 74.0% | 84 min | 2.91% | C |
| IAD to PHX · Phoenixthin sample | 98 | 89.4% | 77 min | 4.08% | A− |
| IAD to RDU · Raleighthin sample | 93 | 89.7% | 191 min | 6.45% | A− |
| IAD to LAS · Las Vegasthin sample | 90 | 84.9% | 65 min | 4.44% | B− |
| IAD to BDL · Hartfordthin sample | 85 | 93.8% | 85 min | 4.71% | A− |
| IAD to DTW · Detroitthin sample | 84 | 61.2% | 82 min | 4.76% | D− |
| IAD to CMH · Columbusthin sample | 80 | 85.3% | 38 min | 6.25% | A− |
| IAD to LGA · New Yorkthin sample | 80 | 86.7% | 61 min | 6.25% | A− |
| IAD to MIA · Miamithin sample | 76 | 73.6% | 37 min | 5.26% | C− |
| IAD to SJU · San Juanthin sample | 74 | 78.6% | 76 min | 5.41% | B− |
| IAD to AUS · Austinthin sample | 71 | 83.3% | 84 min | 7.04% | B− |
Delay causes
What held IAD up in January
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 55,000 reported delay minutes.
- 35%Carrier
- 28%Late-arriving aircraft
- 21%National Airspace System
- 16%Extreme weather
Extreme weather accounts for 16% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the comparison with the other months below is the more useful view of the risk. The national share is 10%, so this operation carries roughly 1.6 times the usual weather exposure. The split is drawn from 55,329 reported delay minutes.
Cancellations run at 5.65%, against 4.71% nationally. That is roughly one flight in twenty cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
6.4% of arrivals land an hour or more late, close to the national 7.6%. 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 a little over an hour, which a normal layover absorbs.
What to do with this
Flying from IAD in January
For a January trip through IAD: expect 83.0% on time and 5.65% cancelled, going by January 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 February83.3%
- IAD in March79.6%
- 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.