Carrier route record

DLGRB→DTW

Delta Air Lines · Green Bay to Detroit

Flights: 187
Period: July 2025 to June 2026
Share of route: 23%
Carriers: 2

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.

Delta on GRB to DTW lands a B, 4 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 a little over an hour on average. That is a workable record, not a spotless one. That rests on 187 flights, with a median arrival 20 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Delta on GRB to DTW from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

81.3%

Arrivals under 15 minutes late, of 182 completed flights

Avg delay

77 min

Across delayed arrivals only, not all flights

Cancelled

1.60%

National rate is 1.81%

Whole route

80.2%

Every carrier on GRB to DTW, 812 flights

These figures cover 187 flights between July 2025 and June 2026. Beyond the headline rate, 8.2% 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

Delta against every carrier on GRB to DTW

Delta flew 187 of the 812 flights on GRB to DTW, about 23% of it. Its 81.3% on time is about level with the route as a whole at 80.2%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 81.3% to SkyWest at 79.9%.

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.

On-time performance by carrier on GRB to DTW
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines (this page)thin sample	187	81.3%	77 min	1.60%	B
SkyWest Airlines	625	79.9%	112 min	2.24%	B

Departure window

When Delta runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 187 flights.

There are not enough flights in each departure window to split Delta's GRB to DTW record by time of day without the percentages moving on noise. The headline rate of 81.3% is the reliable figure here.

Across the year

Delta on GRB to DTW through the year

Jul–Sep 202522 flights—
Oct–Dec 202577 flights85.5%
Jan–Mar 202678 flights74.3%
Apr–Jun 202610 flights—

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 81.3% on time across 187 flights.

Split by quarter, Delta on GRB to DTW logged 22 flights in Jul–Sep 2025, 77 flights in Oct–Dec 2025, 78 flights in Jan–Mar 2026 and 10 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 81.3% annual figure is the one to use.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 76% of the 2,611 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.

Late-arriving aircraft
76%
Carrier
14%
National Airspace System
10%
Extreme weather
0%

76% 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 2,611 reported delay minutes here, that single category outweighs weather by 76 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 2,611 reported delay minutes.

Cancellations sit at 1.60% against a national 1.81%, which is ordinary. Diversions add another 1.07%.

Connections and stage length

What a delay here costs

8.2% 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 a little over an hour, which a normal layover absorbs.

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 5pm–8pm window matters as much as it does.

The return leg is a different operation and performs like one: it runs 67.8% on time across 186 flights, 14 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 14 points of difference.

One caution: this is a thin sample. 187 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.

What to do with this

Booking Delta on GRB to DTW

Put together: treat all of this as provisional. 187 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 81.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 182 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures