Route reliability record
MDW→GRR
Chicago to Grand Rapids
- Flights
- 931
- Period
- July 2025 to June 2026
- Distance
- 137 mi
- Carriers
- 1
This route sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 931 MDW to GRR flights, with a median arrival 2 minutes early.
Best time to fly MDW to GRR: a 8am–11am departure, ideally on a Wednesday. Flights in that window arrived on time 88.3% of the time and Wednesday flights 84.8%, against 75.2% 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
75.2%
Arrivals under 15 minutes late, of 922 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
0.86%
National rate is 1.81%
Best carrier
Southwest
75.2% 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 MDW to GRR
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 | 75.2% | 57 min | 0.86% | B+ |
Best ways to make this trip
The most reliable ways to fly Chicago to Grand Rapids
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. MDW → GRRChicago to Grand Rapids | Southwest Airlines | 74.6% | 75.2% | 0.86% | 8am–11am, Wed | — |
| 2. ORD → GRRChicago to Grand Rapids | Envoy Air | 73.1% | 76.1% | 3.88% | 5am–8am, Sat | — |
| 3. ORD → GRRChicago to Grand Rapids | Republic Airways | 72.2% | 74.5% | 3.03% | 2pm–5pm, Thu | — |
| 4. ORD → AZOChicago to Kalamazoo | Envoy Air | 72.2% | 75.3% | 4.16% | 8am–11am, Sat | — |
| 5. ORD → LANChicago to Lansing | Envoy Air | 71.8% | 73.9% | 2.83% | 11am–2pm, Tue | — |
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 26 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–8am—
- 8am–11am311 flights88.3%
- 11am–2pm107 flights66.4%
- 2pm–5pm153 flights83.0%
- 5pm–8pm23 flights—
- 8pm–5am337 flights62.5%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 62.5% on time, against 88.3% for the 8am–11am 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 8pm–5am window is the busiest, with 337 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 23 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.
June is the worst month at 64.7% on time, 23 points below November, the best at 87.7%. 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. July was the busiest month here, with 89 flights.
Across the week, Wednesday is the strongest day at 84.8% on time and Sunday the weakest at 70.1%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 13,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 50%Late-arriving aircraft
- 35%Carrier
- 12%National Airspace System
- 3%Extreme weather
- 1%Security
50% 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 13,000 reported delay minutes here, that single category outweighs weather by 16 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 12,933 reported delay minutes.
The largest share of delay minutes, 35%, 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 4,471 of the 13,000 delay minutes reported here.
Cancellations are rare at 0.86%, 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
7.8% 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 about an hour, which a normal layover absorbs.
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 8am–11am window matters as much as it does.
The return leg runs 77.2% 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 GRR 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 75.2% 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
MDW to GRR questions
How often is MDW to GRR delayed?
About 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 24.8% of the 931 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is MDW to GRR compared with the rest of the country?
75.2% of flights arrive on time here against a national 77.6%, a difference of 2 points against it. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on MDW to GRR?
The 8am–11am departure window is the strongest at 88.3% on time. The 8pm–5am window is the weakest at 62.5%, 26 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 June delays on MDW to GRR?
June is the weakest month at 64.7% on time, compared with 87.7% in November. Across the year that is 23 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
- GRR to MDW — the return legseparate record
- Chicago Midway International (MDW) delay statistics
- MDW to ATL, a related route79.8%
- ORD to GRR, a related route70.0%
- MDW to PHX, a related route75.0%
- Southwest Airlines on-time record75.2%
- 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. MDW to GRR and GRR to MDW 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.