Route reliability record
RDU→DTW
Raleigh to Detroit
- Flights
- 1,525
- Period
- July 2025 to June 2026
- Distance
- 501 mi
- Carriers
- 3
This route earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 1,525 RDU to DTW flights, with a median arrival 13 minutes early.
Best time to fly RDU to DTW: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 93.1% of the time and Tuesday flights 92.7%, against 87.7% for the route overall.
Set against the rest of the country, this route's record is 10 points better than the US average of 77.6%. That gap is worth roughly 101 fewer late arrivals for every thousand flights.
Key figures
On time
87.7%
Arrivals under 15 minutes late, of 1,507 completed flights
Avg delay
80 min
Across delayed arrivals only, not all flights
Cancelled
1.11%
National rate is 1.81%
Best carrier
Delta
88.0% on time across 1,337 flights
These figures cover 1,525 flights between July 2025 and June 2026. The median arrival is 13 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Which airline is most reliable on RDU 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 Lines | 1,337 | 88.0% | 82 min | 1.20% | A |
| Frontier Airlinesthin sample | 111 | 87.3% | 56 min | 0.90% | A+ |
| Spirit Airlinesthin sample | 77 | 83.1% | 77 min | 0.00% | B+ |
Flight by flight
Flights on RDU to DTW
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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 13 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–8am365 flights93.1%
- 8am–11am348 flights93.0%
- 11am–2pm371 flights85.8%
- 2pm–5pm49 flights83.7%
- 5pm–8pm391 flights80.1%
- 8pm–5am1 flights—
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.1% of the time, against 80.1% for the evening window. That is 13 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 391 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 20 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 75.4% on time, against 95.7% 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. August was the busiest month here, with 151 flights.
Across the week, Tuesday is the strongest day at 92.7% on time and Sunday the weakest at 82.9%. 10 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. Late-arriving aircraft accounts for 51% of the 15,000 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.
- 51%Late-arriving aircraft
- 30%Carrier
- 18%National Airspace System
- 1%Extreme weather
51% 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 15,000 reported delay minutes here, that single category outweighs weather by 44 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 14,817 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.1% on time here.
Cancellations sit at 1.11% against a national 1.81%, which is ordinary. Diversions add another 0.07%.
Connections and stage length
What a delay here actually costs
5.4% of arrivals land an hour or more late, close to the national 8.1%. 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 a little over an hour, which a normal layover absorbs.
The 501 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 83.8% on time across 1,525 flights, 4 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 4 points of difference.
The sample behind these figures is 1,525 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 95.7% on time and December 75.4%, a swing of 20 points. If the dates move at all, move them out of December before you think about anything else. 1,507 completed flights over 12 months sit behind that.
Common questions
RDU to DTW questions
How often is RDU to DTW delayed?
About one flight in eight arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 12.3% of the 1,525 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is RDU to DTW compared with the rest of the country?
87.7% of flights arrive on time here against a national 77.6%, a difference of 10 points in its favour. That is worth a A on this site's grading scale.
What time of day has the fewest delays on RDU to DTW?
The 5am–8am departure window is the strongest at 93.1% on time. The 5pm–8pm window is the weakest at 80.1%, 13 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 RDU to DTW?
December is the weakest month at 75.4% on time, compared with 95.7% in October. Across the year that is 20 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 RDU — the return legseparate record
- Raleigh-Durham International (RDU) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Delta Air Lines on RDU to DTW88.0%
- Frontier Airlines on RDU to DTW87.3%
- RDU to ATL, a related route87.6%
- ORD to DTW, a related route70.6%
- RDU to ORD, a related route74.4%
- Delta Air Lines on-time record88.0%
- Frontier Airlines on-time record87.3%
- Spirit Airlines on-time record83.1%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. RDU to DTW and DTW to RDU 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.