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DelayAtlas

Route reliability record

DTWRDU

Detroit to Raleigh

Flights
1,525
Period
July 2025 to June 2026
Distance
501 mi
Carriers
3
BGRADE

This route lands a B, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 1,525 DTW to RDU flights, with a median arrival 9 minutes early.

Best time to fly DTW to RDU: a 11am–2pm departure, ideally on a Tuesday. Flights in that window arrived on time 93.5% of the time and Tuesday flights 86.8%, against 83.8% for the route overall.

Set against the rest of the country, this route's record is 6 points better than the US average of 77.6%. That gap is worth roughly 62 fewer late arrivals for every thousand flights.

Key figures

On time

83.8%

Arrivals under 15 minutes late, of 1,504 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

1.31%

National rate is 1.81%

Best carrier

Delta

84.2% on time across 1,337 flights

These figures cover 1,525 flights between July 2025 and June 2026. The median arrival is 9 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 DTW to RDU

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.

On-time performance by carrier on DTW to RDU
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines1,33784.2%63 min1.20%B
Spirit Airlinesthin sample7783.1%76 min0.00%B+
Frontier Airlinesthin sample11180.4%63 min3.60%B−

Flight by flight

Flights on DTW to RDU

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 19 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–8am261 flights91.8%
  • 8am–11am421 flights86.6%
  • 11am–2pm46 flights93.5%
  • 2pm–5pm375 flights83.7%
  • 5pm–8pm58 flights81.8%
  • 8pm–5am364 flights74.1%

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 93.5% on time, ahead of 8pm–5am at 74.1%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 8am–11am window is the busiest, with 421 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 18 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.

On-time rate by calendar month78J89F79M87A82M90J78J86A90S89O85N72D
Darker means more delays. Figures are on-time percentages.June best, December worst

December is the weak month at 72.1% on time, against 90.2% in June. 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 86.8% on time and Sunday the weakest at 78.5%. 8 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week85.0Mon86.8Tue85.5Wed82.3Thu86.3Fri82.7Sat78.5Sun
Monday: 85.0 percent on time. Tuesday: 86.8 percent on time. Wednesday: 85.5 percent on time. Thursday: 82.3 percent on time. Friday: 86.3 percent on time. Saturday: 82.7 percent on time. Sunday: 78.5 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Carrier accounts for 57% 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.

  • Carrier
    57%
  • Late-arriving aircraft
    21%
  • National Airspace System
    19%
  • Extreme weather
    2%
  • Security
    0%

The largest share of delay minutes, 57%, 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 8,767 of the 15,000 delay minutes reported here. The split is drawn from 15,397 reported delay minutes.

Cancellations sit at 1.31% against a national 1.81%, which is ordinary. Diversions add another 0.07%.

Connections and stage length

What a delay here actually costs

5.7% 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 about 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 87.7% on time across 1,525 flights, 4 points above 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 RDU 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. June runs 90.2% on time and December 72.1%, a swing of 18 points. If the dates move at all, move them out of December before you think about anything else. 1,504 completed flights over 12 months sit behind that.

Common questions

DTW to RDU questions

How often is DTW to RDU delayed?

About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 16.2% of the 1,525 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is DTW to RDU compared with the rest of the country?

83.8% of flights arrive on time here against a national 77.6%, a difference of 6 points in its favour. That is worth a B on this site's grading scale.

What time of day has the fewest delays on DTW to RDU?

The 11am–2pm departure window is the strongest at 93.5% on time. The 8pm–5am window is the weakest at 74.1%, 19 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 DTW to RDU?

December is the weakest month at 72.1% on time, compared with 90.2% in June. Across the year that is 18 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

Direction matters. DTW to RDU and RDU to DTW are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed DTW to RDU’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.