Skip to content
DelayAtlas

Airport month record

RDUAUG

Raleigh-Durham International in August 2025

Departures
4,640
Month
August 2025
National, same month
77.4%
Carriers
10
BGRADE

Historical statistics for August 2025, not live status or a forecast for this year’s August. For today’s conditions at RDU, see live FAA status.

RDU in August lands a B, about a point better than the national rate of 77.4%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 4,640 flights, of which Delta Air Lines flew 1,044 at 85.6% on time.

Delta Air Lines is the most reliable of the five carriers covered here at 85.6% on time across 1,044 flights.

Key figures

On time

78.7%

Arrivals under 15 minutes late, of 4,566 completed departures

Avg delay

82 min

Across delayed arrivals only, not all flights

Cancelled

1.34%

Nationally in August: 1.08%

Whole year

79.0%

RDU across all twelve months

These figures cover 4,640 departures from Raleigh-Durham International in August 2025. 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

August next to RDU's other months

Against RDU's own year, August ran level with the twelve-month rate of 79.0%, which makes it number eight of twelve months, best first. Cancellations were unusually low for RDU in August, at 1.34% against 2.28% across the year. Either side of it, July ran 71.6% on time and September 84.6%, so this month sits in line with its neighbours.

RDU month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 20254,90771.6%97 min3.81%C−
August 2025 (this page)4,64078.7%82 min1.34%B
September 20254,48484.6%81 min0.51%B+
October 20254,92979.0%67 min0.63%B+
November 20254,79680.4%80 min2.04%B
December 20254,80373.5%76 min1.71%C
January 20264,16381.0%76 min8.17%B−
February 20263,95482.1%76 min3.69%B−
March 20264,65877.2%83 min2.81%B
April 20264,74882.4%70 min0.63%B+
May 20264,88481.4%67 min0.86%B+
June 20264,61577.2%84 min2.08%B

Departure window

The best time of day to leave RDU in August

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 29 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am1,120 flights91.7%
  • 8am–11am726 flights89.5%
  • 11am–2pm811 flights79.9%
  • 2pm–5pm744 flights72.6%
  • 5pm–8pm948 flights63.1%
  • 8pm–5am291 flights64.7%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 63.1% on time, against 91.7% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 1,120 flights scheduled in it.

Across the week, Tuesday is the strongest day at 85.0% on time and Friday the weakest at 76.2%. 9 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week78.4Mon85.0Tue79.7Wed76.5Thu76.2Fri79.0Sat78.2Sun
Monday: 78.4 percent on time. Tuesday: 85.0 percent on time. Wednesday: 79.7 percent on time. Thursday: 76.5 percent on time. Friday: 76.2 percent on time. Saturday: 79.0 percent on time. Sunday: 78.2 percent on time

Carrier by carrier

Which airlines ran best at RDU in August

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 85.6% of the time; American Airlines manages 74.3%. Sample sizes sit next to every figure, because a two-point gap across 895 flights means less than a ten-point one.

Carriers at RDU in August 2025
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines1,04485.6%82 min1.25%A
American Airlines89574.3%106 min1.79%C
Southwest Airlines71682.9%57 min0.98%B+
Republic Airways63876.8%63 min1.57%B
United Airlines51978.1%88 min0.19%B+
Frontier Airlinesthin sample35573.0%88 min2.25%C
JetBlue Airwaysthin sample22279.7%89 min0.00%B+
PSA Airlinesthin sample9965.3%62 min4.04%C−
Spirit Airlinesthin sample8472.6%85 min0.00%C+
Alaska Airlinesthin sample5764.8%41 min5.26%D−

Delta leads American by 11 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Route by route

Busiest routes out of RDU in August

Routes from RDU in August 2025
RouteFlightsOn timeAvg delayCancelledGrade
RDU to ATL · Atlanta40288.9%98 min0.75%A+
RDU to ORD · Chicagothin sample27375.6%101 min2.93%B
RDU to CLT · Charlottethin sample26483.5%115 min1.14%B
RDU to LGA · New Yorkthin sample24576.2%69 min2.45%B
RDU to BOS · Bostonthin sample23085.5%77 min0.87%A+
RDU to MCO · Orlandothin sample21272.8%78 min1.42%C
RDU to PHL · Philadelphiathin sample20161.9%96 min1.99%D
RDU to JFK · New Yorkthin sample20177.5%63 min0.50%B+
RDU to MIA · Miamithin sample19669.2%104 min0.51%C+
RDU to DFW · Dallas-Fort Worththin sample19065.7%83 min4.21%C−
RDU to DEN · Denverthin sample16371.1%67 min1.23%C
RDU to DCA · Washingtonthin sample16363.3%88 min3.07%D−
RDU to BNA · Nashvillethin sample16188.2%51 min0.00%A+
RDU to DTW · Detroitthin sample15184.0%54 min0.66%B+
RDU to BWI · Baltimorethin sample15087.8%57 min1.33%A
RDU to EWR · Newarkthin sample14465.3%98 min0.00%C+
RDU to MSP · Minneapolisthin sample11587.8%53 min0.00%A+
RDU to IAD · Washingtonthin sample10884.3%47 min0.00%B+
RDU to TPA · Tampathin sample10176.8%86 min1.98%B
RDU to MDW · Chicagothin sample9481.5%52 min2.13%B
RDU to FLL · Fort Lauderdalethin sample9383.5%76 min2.15%B
RDU to SEA · Seattlethin sample8876.5%42 min3.41%B−
RDU to SFO · San Franciscothin sample8185.2%79 min0.00%A+
RDU to IAH · Houstonthin sample6883.8%53 min0.00%B+
RDU to LAX · Los Angelesthin sample6892.6%84 min0.00%A+

Delay causes

What held RDU up in August

One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 80,000 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.

  • Late-arriving aircraft
    45%
  • Carrier
    28%
  • National Airspace System
    24%
  • Extreme weather
    3%

45% 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 80,000 reported delay minutes here, that single category outweighs weather by 18 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 79,521 reported delay minutes.

Cancellations sit at 1.34% against a national 1.08%, which is ordinary. Diversions add another 0.26%.

8.2% of arrivals land an hour or more late, close to the national 8.2%. 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 RDU in August

For a August trip through RDU: expect 78.7% on time and 1.34% cancelled, going by August 2025. The 5am–8am window was the strongest part of the day.

Related

Where to go next

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.