Route reliability record
GRR→MDW
Grand Rapids to Chicago
- Flights
- 932
- Period
- September 2025 to August 2026
- Distance
- 137 mi
- Carriers
- 1
This route lands a B+, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That rests on 932 GRR to MDW flights, with a median arrival 5 minutes early.
Best time to fly GRR to MDW: a 5am–8am departure, ideally on a Monday. Flights in that window arrived on time 88.9% of the time and Monday flights 81.8%, against 79.2% for the route overall.
The US average over the same twelve months is 77.3%, 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
79.2%
Arrivals under 15 minutes late, of 923 completed flights
Avg delay
44 min
Across delayed arrivals only, not all flights
Cancelled
0.43%
National rate is 1.89%
Best carrier
Southwest
79.2% on time across 932 flights
These figures cover 932 flights between September 2025 and August 2026. The median arrival is 5 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.
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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 | 932 | 79.2% | 44 min | 0.43% | B+ |
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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. GRR → MDWGrand Rapids to Chicago | Southwest Airlines | 78.9% | 79.2% | 0.43% | 5am–8am, Mon | — |
| 2. LAN → ORDLansing to Chicago | Envoy Air | 78.5% | 80.8% | 2.79% | 5am–8am, Tue | — |
| 3. AZO → ORDKalamazoo to Chicago | Envoy Air | 75.9% | 79.3% | 4.32% | 5am–8am, Sat | — |
| 4. GRR → ORDGrand Rapids to Chicago | American Airlines | 71.2% | 74.0% | 3.75% | 8am–11am, Sat | — |
| 5. GRR → ORDGrand Rapids to Chicago | Republic Airways | 70.0% | 72.5% | 3.45% | 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 22 points, against half a point between the best and worst carrier.
- 5am–8am338 flights88.9%
- 8am–11am27 flights—
- 11am–2pm206 flights88.8%
- 2pm–5pm81 flights66.7%
- 5pm–8pm280 flights66.5%
- 8pm–5am—
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 88.9% of the time, against 66.5% for the evening window. That is 22 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 338 flights scheduled in it.
Explore
Filter GRR to MDW by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On GRR to MDW, the best departure window is 5am–8am at 88.9% on time and the worst is 5pm–8pm at 66.5%, a wide gap of 22.4 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am88.9%
- 8–11am—
- 11am–2pm88.8%
- 2–5pm66.7%
- 5–8pm66.5%
- 8pm–5am—
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 19 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 88.6% in August. 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, Monday is the strongest day at 81.8% on time and Sunday the weakest at 76.6%, a spread of 5 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 49% of the 8,530 delay minutes carriers reported here, and the remaining four split what is left.
- 49%Late-arriving aircraft
- 30%National Airspace System
- 19%Carrier
- 3%Extreme weather
49% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 8,530 reported delay minutes here, that single category outweighs weather by 20 to one. The split is drawn from 8,530 reported delay minutes.
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 88.9% on time here.
Cancellations are rare at 0.43%, below the national 1.89% 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 3.0% land an hour or more behind schedule, against 8.3% 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 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 74.6% on time across 932 flights, 5 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
One caution: this is a thin sample. 932 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. 932 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 79.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 923 completed flights over 12 months sit behind that.
Common questions
GRR to MDW questions
How often is GRR to MDW delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.8% of the 932 flights in this analysis, against 22.7% nationally. Delayed flights are late by about 45 minutes on average.
How reliable is GRR to MDW compared with the rest of the country?
79.2% of flights arrive on time here against a national 77.3%, a difference of 2 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on GRR to MDW?
The 5am–8am departure window is the strongest at 88.9% on time. The 5pm–8pm window is the weakest at 66.5%, 22 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 88.6% in August. Across the year that is 19 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 route69.1%
- ATL to MDW, a related route75.2%
- GRR to DTW, a related route79.6%
- Southwest Airlines on-time record79.2%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 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.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.