Route reliability record
GRB→DTW
Green Bay to Detroit
- Flights
- 812
- Period
- July 2025 to June 2026
- Distance
- 287 mi
- Carriers
- 2
This route lands a B, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by close to two hours on average. That is a workable record, not a spotless one. That rests on 812 GRB to DTW flights, with a median arrival 11 minutes early.
Best time to fly GRB to DTW: a 5am–8am departure, ideally on a Thursday. Flights in that window arrived on time 86.7% of the time and Thursday flights 85.7%, against 80.2% 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
80.2%
Arrivals under 15 minutes late, of 793 completed flights
Avg delay
104 min
Across delayed arrivals only, not all flights
Cancelled
2.09%
National rate is 1.81%
Best carrier
SkyWest
79.9% on time across 625 flights
These figures cover 812 flights between July 2025 and June 2026. Beyond the headline rate, 11.0% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on GRB to DTW
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 |
|---|---|---|---|---|---|
| Delta Air Linesthin sample | 187 | 81.3% | 77 min | 1.60% | B |
| SkyWest Airlines | 625 | 79.9% | 112 min | 2.24% | B |
Best ways to make this trip
The most reliable ways to fly Green Bay to Detroit
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. 1 of the top 2 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. GRB → DTWGreen Bay to Detroit | SkyWest Airlines | 78.1% | 79.9% | 2.24% | 5am–8am, Thu | — |
| 2. ATW → DTWAppleton to Detroit | SkyWest Airlines | 77.0% | 78.2% | 1.51% | 5am–8am, Sat (route) | OO 4176 07:00 |
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 11 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–8am269 flights86.7%
- 8am–11am—
- 11am–2pm267 flights75.3%
- 2pm–5pm11 flights—
- 5pm–8pm265 flights79.5%
- 8pm–5am—
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 75.3% on time against 86.7% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 5am–8am window is the busiest, with 269 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 30 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.
Delays peak in March, when the on-time rate falls to 67.5%. June is the strongest month at 97.1%. Moving a flexible trip across that boundary buys 30 points. May was the busiest month here, with 93 flights.
Across the week, Thursday is the strongest day at 85.7% on time and Friday the weakest at 75.9%. 10 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. Carrier accounts for 64% of the 16,000 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.
- 64%Carrier
- 18%Extreme weather
- 12%Late-arriving aircraft
- 6%National Airspace System
Extreme weather accounts for 18% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.9 times the usual weather exposure. The split is drawn from 16,343 reported delay minutes.
The largest share of delay minutes, 64%, 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 10,000 of the 16,000 delay minutes reported here.
Cancellations sit at 2.09% against a national 1.81%, which is ordinary. Diversions add another 0.25%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.0% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 287 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 72.3% on time across 812 flights, 8 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 8 points of difference.
One caution: this is a thin sample. 812 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 DTW after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 812 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 80.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 793 completed flights over 12 months sit behind that.
Common questions
GRB to DTW questions
How often is GRB to DTW 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 19.8% of the 812 flights in this analysis, against 22.4% nationally. Delayed flights are late by close to two hours on average.
How reliable is GRB to DTW compared with the rest of the country?
80.2% of flights arrive on time here against a national 77.6%, a difference of 3 points in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on GRB to DTW?
The 5am–8am departure window is the strongest at 86.7% on time. The 11am–2pm window is the weakest at 75.3%, 11 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 March delays on GRB to DTW?
March is the weakest month at 67.5% on time, compared with 97.1% in June. Across the year that is 30 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
- DTW to GRB — the return legseparate record
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Delta Air Lines on GRB to DTW81.3%
- SkyWest Airlines on GRB to DTW79.9%
- GRB to ORD, a related route71.1%
- ORD to DTW, a related route70.6%
- GRB to MSP, a related route81.1%
- Delta Air Lines on-time record81.3%
- SkyWest Airlines on-time record79.9%
- How often a connection fails at the major US hubs
- The best time of day to fly, according to 7.04 million flight records
Direction matters. GRB to DTW and DTW to GRB 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.