Route profile
IAD→ORD
Flight reliability, delays and best times to fly from Washington to Chicago, 588 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 53% of comparable major US routes (4,598 compared)
Calculated from 5,764 flights. How this is calculated
IAD → ORD arrives on time 78.2% of the time; the return trip, ORD → IAD, arrives on time 77.0% of the time.
IAD → ORD spends 37.3 minutes on the ground on a 588-mile trip: 20.4 minutes from pushback to wheels-up at IAD and 16.9 minutes from touchdown to gate at ORD.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Every day of the week performs about the same on this route, steadier than 95% of 4,467 comparable routes.
80.2% on time on the best day (Tuesday) against 76.0% on the worst (Friday).
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 4,467 in the comparison.
What sets this route apart
Where IAD to ORD differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
IAD to ORD struggles most at 5 PM: 57.6% of its flights scheduled then arrive on time, 13.1 points behind the 70.7% on routes of similar length at the same hour. Against all other routes the gap is 12.2 points.
IAD to ORD is at its best against routes of similar length for flights scheduled at 10 PM: 79.8% arrive on time, 11.5 points ahead of the 68.3% those routes manage at that hour. Against all other routes the gap is 8.2 points.
IAD to ORD holds up on Sundays better than routes of similar length do: 78.5% on time to their 75.2%, a 3.3 points lead. Against all other routes the gap is 3.7 points.
March is kinder to IAD to ORD than to routes of similar length: 84.5% on time against 78.6%, 5.9 points better. Against all other routes the gap is 6.6 points.
In January, IAD to ORD runs 4.9 points below routes of similar length, 74.6% on time to 79.5%. Against all other routes the gap is 4.5 points.
IAD to ORD against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 5 PM departures | 57.6% | routes of similar length | 70.7% | −13.1 pts | 1,112 here, 126,942 there |
| Hour: 10 PM departures | 79.8% | routes of similar length | 68.3% | +11.5 pts | 1,106 here, 47,890 there |
| Weekday: Sunday | 78.5% | routes of similar length | 75.2% | +3.3 pts | 811 here, 289,056 there |
| Month: March | 84.5% | routes of similar length | 78.6% | +5.9 pts | 419 here, 160,915 there |
| Month: January | 74.6% | routes of similar length | 79.5% | −4.9 pts | 366 here, 143,991 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 588 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
Why IAD → ORD flights are cancelled
July 2023 – July 2026
IAD → ORD cancelled 50 of 5,764 scheduled flights — about 1 in every 115. The reason filed most often was extreme weather, 56.0% of the cancellations coded on this route — about 1 in every 206 scheduled flights.
Share of cancellations
Of 50 cancelled departures carrying a reason code.
What each reason means
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
28 cancellations, 56.0% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
21 cancellations, 42.0% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
1 cancellation, 2.0% of the total.
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. With only one or two carriers on the route, the split mostly reflects how they file. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
50 coded cancellations were recorded on IAD → ORD; the section appears from 50.
When it goes wrong
July 2023 – July 2026
40 min late
against a median of 5 min early
Percentiles over 5,764 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at ORD after arriving from IAD.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 38% | Likely to miss |
| 45 min | 21% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 7.0% | Some risk |
| 120 min | 5.0% | Low 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 0.87% of the time and diverts 0.17% of the time, which a late arrival never shows up in.
Chance of missing is the share of 5,704 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 40 minutes late (90th-percentile gate arrival delay), over 5,764 operations.
Any other layover length: connection checker.
Best time to fly
IAD → ORD flights departing 9 AM–12 PM arrived on time 90.6% of the time, against 58.9% for 3–6 PM departures, a gap of 31.7 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 93.1% on time from 764 flights
- 7 AM: too few flights to score
- 8 AM: 85.3% on time from 1,127 flights
- 9 AM: too few flights to score
- 10 AM: 90.5% on time from 149 flights
- 11 AM: too few flights to score
- 12 PM: 87.8% on time from 528 flights
- 1 PM: 81.1% on time from 601 flights
- 2 PM: too few flights to score
- 3 PM: 64.2% on time from 267 flights
- 4 PM: too few flights to score
- 5 PM: 57.6% on time from 1,127 flights
- 6 PM to 9 PM: too few flights to score
- 10 PM: 79.8% on time from 1,119 flights
- 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why IAD → ORD runs late
July 2023 – July 2026
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for IAD → ORD. Only delays of 15 minutes or more are attributed.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 5,764 | 78.2% | 0.87% | -5 min | 7.1% |
Other ways to fly Washington to Chicago
Airport pairs in the same two city markets, as the DOT defines them.
| Route | Flights | On time | Cancelled | Median delay | Score |
|---|---|---|---|---|---|
| DCA→ORD Washington to Chicago | 20,170 | 79.0% | 2.47% | -8 min | 55 |
| IAD→ORD this route Washington to Chicago | 5,764 | 78.2% | 0.87% | -5 min | 67 |
IAD → ORD is the most reliable pairing for this journey at 78.2% on time, against 79.0% for DCA → ORD.
Flying to ORD from the Washington area? Compare IAD, DCA, BWI for ORD, with the same test for what counts as a real difference.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Friday the least, a gap of 4.2 percentage points.
By month
- Jan: 74.6%
- Feb: 84.2%
- Mar: 84.5%
- Apr: 79.8%
- May: 75.4%
- Jun: 77.4%
- Jul: 66.7%
- Aug: 74.1%
- Sep: 81.8%
- Oct: 82.6%
- Nov: 84.9%
- Dec: 81.4%
July is historically the weakest month and November the strongest, a spread of 18.2 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 63.7% from 150 flights
- August 2023: 78.3% from 160 flights
- September 2023: 75.9% from 160 flights
- October 2023: 86.7% from 160 flights
- November 2023: 90.9% from 121 flights
- December 2023: 89.4% from 123 flights
- January 2024: 73.3% from 124 flights
- February 2024: too few flights to score (117)
- March 2024: 93.7% from 126 flights
- April 2024: 87.5% from 120 flights
- May 2024: 76.1% from 156 flights
- June 2024: 78.0% from 150 flights
- July 2024: 73.6% from 154 flights
- August 2024: 67.3% from 156 flights
- September 2024: 92.1% from 151 flights
- October 2024: 89.7% from 155 flights
- November 2024: 87.2% from 149 flights
- December 2024: 80.5% from 128 flights
- January 2025: 77.7% from 124 flights
- February 2025: too few flights to score (112)
- March 2025: 83.4% from 152 flights
- April 2025: 78.8% from 180 flights
- May 2025: 73.1% from 186 flights
- June 2025: 74.4% from 180 flights
- July 2025: 63.7% from 185 flights
- August 2025: 76.0% from 196 flights
- September 2025: 78.8% from 203 flights
- October 2025: 72.7% from 176 flights
- November 2025: 77.7% from 151 flights
- December 2025: 75.3% from 146 flights
- January 2026: 72.8% from 129 flights
- February 2026: too few flights to score (112)
- March 2026: 77.5% from 148 flights
- April 2026: 75.7% from 181 flights
- May 2026: 76.9% from 217 flights
- June 2026: 79.4% from 210 flights
- July 2026: 66.5% from 216 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 75.4% against 78.8% in the 12 months before — declining by 3.4 percentage points.
Data and methodology
Calculated by FlyerIntel from 5,764 IAD → 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
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed