Route reliability record
IAD→DTW
Washington to Detroit
- Flights
- 1,096
- Period
- July 2025 to June 2026
- Distance
- 383 mi
- Carriers
- 4
This route lands a B, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That is a workable record, not a spotless one. That rests on 1,096 IAD to DTW flights, with a median arrival 7 minutes early.
Best time to fly IAD to DTW: a 8am–11am departure, ideally on a Thursday. Flights in that window arrived on time 88.5% of the time and Thursday flights 84.7%, against 76.7% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.7%
Arrivals under 15 minutes late, of 1,077 completed flights
Avg delay
107 min
Across delayed arrivals only, not all flights
Cancelled
1.55%
National rate is 1.81%
Best carrier
SkyWest
75.5% on time across 754 flights
These figures cover 1,096 flights between July 2025 and June 2026. Beyond the headline rate, 11.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on IAD to DTW
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Linesthin sample | 94 | 81.5% | 77 min | 2.13% | B |
| United Airlinesthin sample | 39 | 79.5% | 49 min | 0.00% | B+ |
| Republic Airwaysthin sample | 209 | 78.3% | 57 min | 2.39% | B |
| SkyWest Airlines | 754 | 75.5% | 124 min | 1.33% | B |
Best ways to make this trip
The most reliable ways to fly Washington to Detroit
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. BWI → DTWBaltimore to Detroit | Delta Air Lines | 85.4% | 86.8% | 1.66% | 5am–8am, Tue | DL 2601 06:00 |
| 2. DCA → DTWWashington to Detroit | Delta Air Lines | 77.6% | 79.6% | 2.46% | 5am–8am, Sat | DL 2869 06:00 |
| 3. IAD → DTWWashington to Detroit | SkyWest Airlines | 74.5% | 75.5% | 1.33% | 8am–11am, Thu | — |
| 4. BWI → DTWBaltimore to Detroit | Southwest Airlines | 74.4% | 75.8% | 1.91% | 11am–2pm, Wed | — |
| 5. DCA → DTWWashington to Detroit | PSA Airlines | 65.1% | 69.5% | 6.37% | 5am–8am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 20 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am278 flights84.2%
- 8am–11am96 flights88.5%
- 11am–2pm191 flights79.4%
- 2pm–5pm—
- 5pm–8pm453 flights68.8%
- 8pm–5am78 flights74.3%
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 88.5% of the time, against 68.8% for the evening window. That is 20 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 453 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 38 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 55.7% on time, against 93.3% in October. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 144 flights.
Across the week, Thursday is the strongest day at 84.7% on time and Monday the weakest at 72.0%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 71% of the 27,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 71%Carrier
- 12%National Airspace System
- 10%Extreme weather
- 6%Late-arriving aircraft
- 2%Security
The largest share of delay minutes, 71%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 19,000 of the 27,000 delay minutes reported here. The split is drawn from 26,864 reported delay minutes.
Cancellations sit at 1.55% against a national 1.81%, which is ordinary. Diversions add another 0.18%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.8% of arrivals land a full hour or more behind schedule, against 8.1% 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.
At 383 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.
The return leg runs 74.0% on time across 1,115 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,096 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in DTW after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. October runs 93.3% on time and December 55.7%, a swing of 38 points. If the dates move at all, move them out of December before you think about anything else. 1,077 completed flights over 12 months sit behind that.
Common questions
IAD to DTW questions
How often is IAD to DTW delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.3% of the 1,096 flights in this analysis, against 22.4% nationally. Delayed flights are late by close to two hours on average.
How reliable is IAD to DTW compared with the rest of the country?
76.7% of flights arrive on time here against a national 77.6%, a difference of about a point against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on IAD to DTW?
The 8am–11am departure window is the strongest at 88.5% on time. The 5pm–8pm window is the weakest at 68.8%, 20 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on IAD to DTW?
December is the weakest month at 55.7% on time, compared with 93.3% in October. Across the year that is 38 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- DTW to IAD — the return legseparate record
- Washington Dulles International (IAD) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Republic Airways on IAD to DTW78.3%
- SkyWest Airlines on IAD to DTW75.5%
- IAD to ATL, a related route79.2%
- ORD to DTW, a related route70.6%
- IAD to DEN, a related route81.7%
- Delta Air Lines on-time record81.5%
- United Airlines on-time record79.5%
- Republic Airways on-time record78.3%
- The best time of day to fly, according to 7.04 million flight records
- How often a connection fails at the major US hubs
Direction matters. IAD to DTW and DTW to IAD are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.