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DelayAtlas

Carrier route record

YXBOSBWI

Republic Airways · Boston to Baltimore

Flights
1,086
Period
July 2025 to June 2026
Share of route
31%
Carriers
3
B−GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Republic Airways.

Republic on BOS to BWI carries a cancellation problem, not just a delay problem: 3.3% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about four flights in five arrive on time, worth a B− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,086 flights, with a median arrival 12 minutes early.

Set against the rest of the country, Republic's BOS to BWI record is 4 points better than the US average of 77.6%. That gap is worth roughly 43 fewer late arrivals for every thousand flights.

Key figures

On time

81.9%

Arrivals under 15 minutes late, of 1,047 completed flights

Avg delay

76 min

Across delayed arrivals only, not all flights

Cancelled

3.31%

National rate is 1.81%

Whole route

78.9%

Every carrier on BOS to BWI, 3,551 flights

These figures cover 1,086 flights between July 2025 and June 2026. The median arrival is 12 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

Republic against every carrier on BOS to BWI

Republic flew 1,086 of the 3,551 flights on BOS to BWI, about 31% of it. Its 81.9% on time is 3 points better than the route as a whole, which runs 78.9%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from Republic at 81.9% to Spirit at 73.0%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

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 BOS to BWI
AirlineFlightsOn timeAvg delayCancelledGrade
Republic Airways (this page)1,08681.9%76 min3.31%B−
Southwest Airlines2,37077.8%72 min2.28%B
Spirit Airlinesthin sample9573.0%67 min6.32%C−

Flight by flight

Republic flight numbers on BOS to BWI

Departure window

When Republic runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 36 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–8am120 flights96.6%
  • 8am–11am281 flights88.4%
  • 11am–2pm197 flights86.8%
  • 2pm–5pm171 flights77.8%
  • 5pm–8pm190 flights75.3%
  • 8pm–5am127 flights60.5%

Scale runs 50% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 60.5% on time, against 96.6% 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 8am–11am window is the busiest, with 281 flights scheduled in it.

Across the year

Republic on BOS to BWI through the year

On-time rate by calendar month86J80F86M83A85M83J73J89A78S76O87N80D
Darker means more delays. Figures are on-time percentages.August best, July worst

July is the worst month at 73.0% on time, 16 points below August, the best at 89.2%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. October was the busiest month here, with 107 flights.

Across the week, Wednesday is the strongest day at 88.1% on time and Sunday the weakest at 74.5%. 14 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week75.8Mon83.6Tue88.1Wed86.5Thu80.6Fri84.0Sat74.5Sun
Monday: 75.8 percent on time. Tuesday: 83.6 percent on time. Wednesday: 88.1 percent on time. Thursday: 86.5 percent on time. Friday: 80.6 percent on time. Saturday: 84.0 percent on time. Sunday: 74.5 percent on time

Delay causes

Why Republic runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 14,000 reported delay minutes.

  • Late-arriving aircraft
    37%
  • Carrier
    36%
  • National Airspace System
    27%
  • Extreme weather
    1%

37% 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 14,000 reported delay minutes here, that single category outweighs weather by 37 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 14,392 reported delay minutes.

The largest share of delay minutes, 36%, 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 5,131 of the 14,000 delay minutes reported here.

Cancellations run at 3.31%, against 1.81% nationally. That is about one flight in 30 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 costs

7.2% 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.

At 369 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 80.8% on time across 1,086 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 1,086 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Republic on BOS to BWI

Put together: the delay figures matter less here than the 3.31% 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. 1,047 completed flights over 12 months sit behind that.

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.