Skip to content
DelayAtlas

Route reliability record

DCABOS

Washington to Boston

Flights
9,071
Period
June 2025 to May 2026
Distance
399 mi
Carriers
4
C−GRADE

This route carries a cancellation problem, not just a delay problem: 3.9% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about seven flights in ten arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 9,071 flights, of which Republic Airways flew 4,010 at 77.2% on time.

Republic Airways is the most reliable of the three carriers covered here at 77.2% on time across 4,010 flights.

Key figures

On time

70.8%

Arrivals under 15 minutes late, of 8,716 completed flights

Avg delay

80 min

Across delayed arrivals only, not all flights

Cancelled

3.89%

National rate is 1.80%

Best carrier

Republic

77.2% on time across 4,010 flights

These figures cover 9,071 flights between June 2025 and May 2026. Beyond the headline rate, 13.4% 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 DCA to BOS

The choice of carrier is not cosmetic here. Republic Airways arrives on time 77.2% of the time; JetBlue Airways manages 65.2%. Sample sizes sit next to every figure, because a two-point gap across 2,645 flights means less than a ten-point one.

On-time performance by carrier on DCA to BOS
AirlineFlightsOn timeAvg delayCancelledGrade
Envoy Airthin sample17679.2%82 min4.55%B−
Republic Airways4,01077.2%70 min4.51%B−
American Airlines2,24065.4%82 min3.08%C−
JetBlue Airways2,64565.2%87 min3.59%C−

Republic Airways cancels 4.5% 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.

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 37 points, against 12 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am1,222 flights90.9%
  • 8am–11am1,621 flights84.4%
  • 11am–2pm1,772 flights74.8%
  • 2pm–5pm1,588 flights58.6%
  • 5pm–8pm1,649 flights53.6%
  • 8pm–5am1,219 flights65.0%

Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 53.6% on time, against 90.9% 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.

Across the year

When delays peak on this route

This route's year swings by 22 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 month76J71F67M73A75M69J69J83A61S65O72N70D
Darker means more delays. Figures are on-time percentages.August best, September worst

Delays peak in September, when the on-time rate falls to 60.7%. August is the strongest month at 82.7%. Moving a flexible trip across that boundary buys 22 points.

Across the week, Saturday is the strongest day at 83.5% on time and Sunday the weakest at 65.8%. 18 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week70.4Mon74.4Tue73.5Wed67.7Thu65.8Fri83.5Sat65.8Sun
Monday: 70.4 percent on time. Tuesday: 74.4 percent on time. Wednesday: 73.5 percent on time. Thursday: 67.7 percent on time. Friday: 65.8 percent on time. Saturday: 83.5 percent on time. Sunday: 65.8 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 202,000 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
    47%
  • National Airspace System
    31%
  • Carrier
    19%
  • Extreme weather
    3%
  • Security
    0%

47% 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 202,000 reported delay minutes here, that single category outweighs weather by 17 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 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 90.9% on time here.

Cancellations run at 3.89%, against 1.80% nationally. That is about one flight in 25 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.

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. 13.4% of arrivals land a full hour or more behind schedule, against 8.2% 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 399 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 5am–8am window matters as much as it does.

The return leg runs 73.7% on time across 9,071 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 9,071 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.

What to do with this

Booking this route

Put together: the delay figures matter less here than the 3.89% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic.

Common questions

DCA to BOS questions

How often is DCA to BOS delayed?

Roughly one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 29.2% of the 9,071 flights in this analysis, against 22.6% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on DCA to BOS?

Republic Airways leads at 77.2% on time across 4,010 flights. JetBlue Airways is at the other end on 65.2%, a gap of 12 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on DCA to BOS?

The 5am–8am departure window is the strongest at 90.9% on time. The 5pm–8pm window is the weakest at 53.6%, 37 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 September delays on DCA to BOS?

September is the weakest month at 60.7% on time, compared with 82.7% in August. Across the year that is 22 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

Source: US DOT Bureau of Transportation Statistics, on-time performance data, June 2025 to May 2026. Updated monthly. How this data is collected.