BOS → ORD Flight Reliability

Right now

Origin · BOSNo disruption reported

Aviation weather is not currently a factor.

Updated 07:54 UTC

Boston airport profile →

Destination · ORDNo disruption reported

Aviation weather is not currently a factor.

Updated 07:51 UTC

Chicago airport profile →

Route reliability

July 2023 – July 2026

Route Reliability Score

54/ 100Fair

Better than 22% of comparable major US routes (4,598 compared)

Calculated from 21,884 flights. How this is calculated

On-time arrivals

76.9%

16,441 of 21,372

Cancellation rate

2.02%

442 cancelled

Median arrival delay

-7 min

Average 9.4 min

Severe delays

9.9%

60+ minutes late

Delay when late

82 min

Average, when 15+ min late

Flights analyzed

21,884

6 carriers

BOS → ORD arrives on time 76.9% of the time; the return trip, ORD → BOS, arrives on time 72.4% of the time, a 4.6-point gap between the two directions of the same city pair.

BOS → ORD spends 39.3 minutes on the ground on an 867-mile trip: 20.1 minutes from pushback to wheels-up at BOS and 19.2 minutes from touchdown to gate at ORD.

Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026

Why BOS → ORD flights are cancelled

July 2023 – July 2026

BOS → ORD cancelled 442 of 21,884 scheduled flights — about 1 in every 50. The reason filed most often was extreme weather, 58.8% of the cancellations coded on this route — about 1 in every 84 scheduled flights.

Share of cancellations

Weather58.8%

Airline20.8%

Air traffic20.4%

Security0.0%

Of 442 cancelled departures carrying a reason code.

What each reason means

Extreme weather1 in 84

Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.

260 cancellations, 58.8% of the total.

The airline1 in 238

Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.

92 cancellations, 20.8% of the total.

The air traffic system1 in 243

Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.

90 cancellations, 20.4% of the total.

Security—

A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.

0 cancellations, 0.0% of the total.

Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.

442 coded cancellations were recorded on BOS → ORD; the section appears from 50.

When it goes wrong

July 2023 – July 2026

One arrival in ten is worse than

59 min late

against a median of 7 min early

Arrived an hour or more late9.9%

Typical delay when late82 min

Cancelled2.02%

Landed somewhere else0.32%

BOS → ORD has an average that understates its risk: a typical arrival is 7 min early, but the worst tenth are 66 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.

Percentiles over 21,884 operations; cancelled and diverted flights are counted separately.

Will your connection be tight enough?

Layovers at ORD after arriving from BOS.

Connection buffer and chance of missing by layover length, BOS → ORD arrivals
Connection time	Chance of missing	Reads as
30 min	38%	Likely to miss
45 min	22%	High risk
60 min	16%	High risk
90 min	9.7%	Some risk
120 min	6.5%	Some risk

This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 2.02% of the time and diverts 0.32% of the time, which a late arrival never shows up in.

Chance of missing is the share of 21,372 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.

The worst tenth of arrivals on this route land at least 59 minutes late (90th-percentile gate arrival delay), over 21,884 operations.

Any other layover length: connection checker.

Best time to fly

BOS → ORD flights departing 5–9 AM arrived on time 89.4% of the time, against 59.7% for 6–9 PM departures, a gap of 29.7 percentage points.

By day and hour

On-time arrival rate for each weekday and scheduled departure hour, in local time at the departure airport (BOS).

Hour of departure matters more than day of the week: hourly averages sit a typical 12.7 points from the route-wide rate, weekday averages 2.4 points.

On-time arrival rate for BOS to ORD by weekday and scheduled departure hour, local time. Each button reads out one slot.
Hour	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
6 AM–7 AM
7 AM–8 AM
8 AM–9 AM
9 AM–10 AM
10 AM–11 AM
11 AM–12 PM
12 PM–1 PM
1 PM–2 PM
2 PM–3 PM
3 PM–4 PM
4 PM–5 PM
5 PM–6 PM
6 PM–7 PM
7 PM–8 PM
8 PM–9 PM

On-time rate, % · stronger color, fewer on time

40–49
50–59
60–69
70–79
80–89
90–99

Fewer than 120 flights, not scored

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · On time is arrival within 15 minutes of schedule. Cells round to whole percentages; the table shows one decimal.

No slot is named best or worst: too few reach 500 flights. Departures before 6 AM and after 9 PM (666 flights) are not drawn: no slot in those hours has enough flights to score.

View as tableHide table

On-time arrival rate (%) with flights beneath, by scheduled departure hour and weekday for BOS to ORD. A dash means fewer than 120 flights, which are not scored.
Hour	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
6 AM–7 AM	94.0% on time374 flights	94.5% on time359 flights	93.5% on time361 flights	91.9% on time368 flights	88.6% on time367 flights	90.1% on time310 flights	91.9% on time340 flights
7 AM–8 AM	88.2% on time289 flights	86.7% on time257 flights	86.9% on time256 flights	87.9% on time285 flights	84.9% on time286 flights	78.4% on time254 flights	80.7% on time265 flights
8 AM–9 AM	90.1% on time208 flights	85.8% on time198 flights	88.6% on time205 flights	91.5% on time213 flights	90.9% on time213 flights	93.8% on time228 flights	89.4% on time218 flights
9 AM–10 AM	87.7% on time167 flights	88.3% on time164 flights	90.1% on time163 flights	85.4% on time166 flights	85.4% on time165 flights	83.6% on time177 flights	87.0% on time170 flights
10 AM–11 AM	87.6% on time185 flights	86.4% on time172 flights	86.8% on time169 flights	88.8% on time181 flights	83.4% on time183 flights	91 flights, too few to score	82.9% on time173 flights
11 AM–12 PM	74.5% on time194 flights	86.8% on time162 flights	87.0% on time163 flights	84.1% on time196 flights	76.5% on time185 flights	101 flights, too few to score	80.8% on time159 flights
12 PM–1 PM	86.4% on time279 flights	85.5% on time280 flights	86.3% on time287 flights	86.7% on time282 flights	83.6% on time281 flights	82.6% on time229 flights	81.1% on time274 flights
1 PM–2 PM	101 flights, too few to score	82 flights, too few to score	80 flights, too few to score	100 flights, too few to score	100 flights, too few to score	109 flights, too few to score	91 flights, too few to score
2 PM–3 PM	80.5% on time127 flights	83.6% on time130 flights	82.3% on time132 flights	75.6% on time125 flights	74.8% on time132 flights	78.5% on time137 flights	75.0% on time138 flights
3 PM–4 PM	69.6% on time281 flights	81.1% on time281 flights	72.5% on time281 flights	67.6% on time282 flights	65.8% on time281 flights	72.3% on time215 flights	68.3% on time278 flights
4 PM–5 PM	61.7% on time267 flights	66.8% on time246 flights	59.8% on time248 flights	58.4% on time251 flights	60.1% on time258 flights	63.1% on time202 flights	62.5% on time261 flights
5 PM–6 PM	57.8% on time262 flights	60.7% on time235 flights	60.1% on time242 flights	49.2% on time262 flights	48.5% on time269 flights	63.7% on time271 flights	56.2% on time272 flights
6 PM–7 PM	64.0% on time184 flights	60.8% on time129 flights	66.4% on time131 flights	58.5% on time186 flights	56.0% on time190 flights	69.4% on time146 flights	59.3% on time182 flights
7 PM–8 PM	53.0% on time147 flights	63.6% on time142 flights	59.4% on time134 flights	48.5% on time138 flights	55.9% on time143 flights	88 flights, too few to score	49.3% on time141 flights
8 PM–9 PM	62.3% on time153 flights	99 flights, too few to score	72.8% on time120 flights	53.5% on time150 flights	60.8% on time150 flights	24 flights, too few to score	55.6% on time160 flights

By departure window

5–9 AM89.4%

9 AM–12 PM85.0%

12–3 PM81.3%

3–6 PM63.2%

6–9 PM59.7%

9 PM–5 AM—

By departure hour

12 AM

3 AM

6 AM

9 AM

12 PM

3 PM

6 PM

9 PM

Departure windows with fewer than 120 flights are not scored.

Why BOS → ORD runs late

July 2023 – July 2026

Late-arriving aircraft40.8%

the inbound aircraft was late, so this flight started late

Air traffic control29.9%

airspace and airport capacity, including weather-driven flow control

The airline25.1%

crew, maintenance, boarding and fueling, all within the carrier’s control

Weather4.2%

weather severe enough to stop this flight specifically

Security0.1%

screening or terminal security incidents

Share of the delay minutes US DOT attributed to each cause for BOS → ORD. Only delays of 15 minutes or more are attributed.

Late-arriving aircraft is the largest cause on BOS → ORD, at 40.8%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 89.4% of the time and 6–9 PM departures 59.7%.

How this route holds up in bad weather

July 2023 – July 2026

Bad weather raises cancellations by a similar amount at both ends of BOS to ORD: 3.9 times the normal rate at BOS and 5.5 times at ORD. Cancelled in bad weather against normal hours: BOS 5.3% against 1.4%, ORD 6.5% against 1.2%. Flights that did leave ORD in bad weather arrived on time 55.7% of the time, against 77.1% in normal hours.

Bad weather and normal hours at the airports

Scheduled departures, July 2023 – July 2026

Departures from BOS and ORD in hours of bad weather and in normal hours
Departures from	BOS	ORD
Cancelled in bad weather	5.3%	6.5%
Cancelled in normal hours	1.4%	1.2%
Arrived on time, bad weather	65.1%	55.7%
Arrived on time, normal hours	79.7%	77.1%
Departures in bad weather	60,840	104,455

Of the carriers on this route, Delta Air Lines (3.1% cancelled against 5.8% for the other carriers at BOS) cancelled the fewest departures from BOS in bad weather and Republic Airways (8.1% cancelled against 5.0% for the other carriers at BOS) the most.

This route’s airlines in bad weather at BOS

All departures from BOS

Cancellation rates in bad weather at BOS for the airlines that fly BOS to ORD, against the other carriers at BOS in the same months
Airline	Bad-weather departures	Cancelled	Other carriers
Delta Air Lines	10,971	3.1%below the others	5.8%
Envoy Air	826	4.1%about level	5.3%
American Airlines	6,964	4.7%below the others	5.5%
United Airlines	5,328	4.6%below the others	5.4%
JetBlue	17,332	5.4%about level	5.1%
Republic Airways	12,581	8.1%above the others	5.0%

These are airport figures, not route figures: every scheduled departure from BOS and ORD, to any destination, in hours the weather report called bad. The airline rows count each carrier’s departures from BOS on every route.

Weather source and limits. In full: BOS (airlines), ORD, What Weather Costs Each Airport, Who Cancels More When the Weather Turns, Airports That Change Places When Weather Turns.

Airlines on this route

Carriers with at least 200 flights, by the airline that operated each one.

Airlines on this route
Carrier	Flights	On time	Cancelled	Median delay	Severe
United Airlines	7,613	79.0%	1.56%	-6 min	8.3%
American Airlines	5,429	77.0%	2.03%	-10 min	10.6%
Delta Air Lines	2,912	71.0%	2.03%	-2 min	12.5%
Republic Airways	2,417	78.7%	3.31%	-8 min	8.6%
JetBlue	1,824	73.1%	1.43%	-5 min	11.3%
Envoy Air	1,416	79.2%	2.33%	-11 min	9.9%

United Airlines flew 35.2% of the 21,611 flights listed. Republic Airways cancelled 3.31% of its flights here against 1.43% for JetBlue.

Envoy Air arrived on time 8.2 percentage points more often than Delta Air Lines on this route.

Flights on this route

Flight numbers with at least 600 operations here and still on the schedule.

Flights on this route
Flight	Scheduled	Operations	On time
B6311 JetBlue	6:00 AM	974	85.2%
UA1732 United Airlines	12:30 PM	967	88.6%
AA1509 American Airlines	7:00 AM	904	91.1%
UA2040 United Airlines	4:27 PM	738	58.0%
UA1414 United Airlines	6:00 AM	677	93.4%

UA1414 (6:00 AM) arrived on time 93.4% of the time, 35.4 points more often than UA2040 (4:27 PM) at 58.0%.

Weekly and seasonal patterns

By day of week

Mon77.3%

Tue80.4%

Wed79.1%

Thu75.3%

Fri73.9%

Sat78.9%

Sun74.2%

Tuesday is historically the most reliable day and Friday the least, a gap of 6.5 percentage points.

By month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

July is historically the weakest month and February the strongest, a spread of 13.3 percentage points.

Reliability over time

July 2023 – July 2026

24

25

26

Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 73.1% against 78.4% in the 12 months before — declining by 5.3 percentage points.

Data and methodology

Calculated by FlyerIntel from 21,884 BOS → ORD flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.

Full methodology · Data sources · Report a problem

Analysis last recomputed September 26, 2026

BOS airport ORD airport Return direction ORD → BOS

BOS→ORD

Right now

Route reliability

Why BOS → ORD flights are cancelled

Share of cancellations

What each reason means

When it goes wrong

Will your connection be tight enough?

Best time to fly

By day and hour

By departure window

By departure hour

Why BOS → ORD runs late

How this route holds up in bad weather

Bad weather and normal hours at the airports

This route’s airlines in bad weather at BOS

Airlines on this route

Flights on this route

Weekly and seasonal patterns

By day of week

By month

Reliability over time

Data and methodology