Route reliability record
GRR→MDW
Grand Rapids to Chicago
- Flights
- 931
- Period
- July 2025 to June 2026
- Distance
- 137 mi
- Carriers
- 1
This route lands a B+, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That is a workable record, not a spotless one. That rests on 931 GRR to MDW flights, with a median arrival 2 minutes early.
Best time to fly GRR to MDW: a 11am–2pm departure, ideally on a Thursday. Flights in that window arrived on time 85.9% of the time and Thursday flights 80.4%, against 77.2% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.2%
Arrivals under 15 minutes late, of 922 completed flights
Avg delay
46 min
Across delayed arrivals only, not all flights
Cancelled
0.43%
National rate is 1.81%
Best carrier
Southwest
77.2% on time across 931 flights
These figures cover 931 flights between July 2025 and June 2026. The median arrival is 2 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
Which airline is most reliable on GRR to MDW
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 931 | 77.2% | 46 min | 0.43% | B+ |
Best ways to make this trip
The most reliable ways to fly Grand Rapids to Chicago
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. LAN → ORDLansing to Chicago | Envoy Air | 78.5% | 80.7% | 2.70% | 5am–8am, Tue | — |
| 2. GRR → MDWGrand Rapids to Chicago | Southwest Airlines | 76.9% | 77.2% | 0.43% | 11am–2pm, Thu | — |
| 3. AZO → ORDKalamazoo to Chicago | Envoy Air | 76.9% | 80.2% | 4.16% | 5am–8am, Sat | — |
| 4. GRR → ORDGrand Rapids to Chicago | American Airlines | 73.0% | 75.6% | 3.38% | 8am–11am, Sat | — |
| 5. GRR → ORDGrand Rapids to Chicago | Republic Airways | 68.9% | 70.9% | 2.87% | 5am–8am, Thu | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 21 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–8am338 flights85.5%
- 8am–11am27 flights—
- 11am–2pm193 flights85.9%
- 2pm–5pm72 flights73.6%
- 5pm–8pm301 flights65.2%
- 8pm–5am—
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 85.9% on time, ahead of 5pm–8pm at 65.2%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5am–8am window is the busiest, with 338 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 17 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.
December is the weak month at 69.5% on time, against 86.4% in October. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 89 flights.
Across the week, Thursday is the strongest day at 80.4% on time and Sunday the weakest at 74.3%. 6 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 9,551 reported delay minutes.
- 41%Late-arriving aircraft
- 37%National Airspace System
- 19%Carrier
- 2%Extreme weather
41% 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 9,551 reported delay minutes here, that single category outweighs weather by 19 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 9,551 reported delay minutes.
37% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,556 minutes out of 9,551, against a national NAS share of 21%.
Cancellations are rare at 0.43%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 3.6% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
At 137 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 11am–2pm window matters as much as it does.
The return leg runs 75.2% on time across 931 flights, within 2 points 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. 931 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.
Work out the risk of missing a connection in MDW after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 931 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 77.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 922 completed flights over 12 months sit behind that.
Common questions
GRR to MDW questions
How often is GRR to MDW delayed?
Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.8% of the 931 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 45 minutes on average.
How reliable is GRR to MDW compared with the rest of the country?
77.2% of flights arrive on time here against a national 77.6%, a difference of half a point against it. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on GRR to MDW?
The 11am–2pm departure window is the strongest at 85.9% on time. The 5pm–8pm window is the weakest at 65.2%, 21 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 December delays on GRR to MDW?
December is the weakest month at 69.5% on time, compared with 86.4% in October. Across the year that is 17 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
- MDW to GRR — the return legseparate record
- Chicago Midway International (MDW) delay statistics
- GRR to ORD, a related route68.3%
- ATL to MDW, a related route76.3%
- GRR to DTW, a related route78.2%
- Southwest Airlines on-time record77.2%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. GRR to MDW and MDW to GRR are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed GRR to MDW’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
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.