Route reliability record
DEN→OAK
Denver to Oakland
- Flights
- 1,610
- Period
- July 2025 to June 2026
- Distance
- 957 mi
- Carriers
- 1
This route draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 50 minutes behind schedule. Build slack into anything you connect to. That rests on 1,610 DEN to OAK flights, with a median arrival 5 minutes late.
Best time to fly DEN to OAK: a 8am–11am departure, ideally on a Wednesday. Flights in that window arrived on time 82.7% of the time and Wednesday flights 69.4%, against 65.1% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 13 points behind the country as a whole. Across a thousand flights that is about 125 extra late arrivals.
Key figures
On time
65.1%
Arrivals under 15 minutes late, of 1,600 completed flights
Avg delay
51 min
Across delayed arrivals only, not all flights
Cancelled
0.62%
National rate is 1.81%
Best carrier
Southwest
65.1% on time across 1,610 flights
These figures cover 1,610 flights between July 2025 and June 2026. Beyond the headline rate, 9.5% 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 DEN to OAK
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 | 1,610 | 65.1% | 51 min | 0.62% | C+ |
Best ways to make this trip
The most reliable ways to fly Denver to Oakland
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. DEN → SJCDenver to San Jose | United Airlines | 80.5% | 80.5% | 0.00% | 8am–11am, Thu | — |
| 2. DEN → SFODenver to San Francisco | United Airlines | 70.9% | 71.2% | 0.42% | 5am–8am, Tue | UA 2367 05:20 |
| 3. DEN → SJCDenver to San Jose | Southwest Airlines | 68.9% | 69.4% | 0.65% | 8am–11am, Wed | — |
| 4. DEN → SFODenver to San Francisco | Frontier Airlines | 66.6% | 67.2% | 0.83% | 5am–8am, Fri | F9 3439 22:29 |
| 5. DEN → OAKDenver to Oakland | Southwest Airlines | 64.7% | 65.1% | 0.62% | 8am–11am, Wed | — |
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 34 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–8am87 flights81.4%
- 8am–11am394 flights82.7%
- 11am–2pm259 flights72.3%
- 2pm–5pm217 flights63.1%
- 5pm–8pm263 flights51.4%
- 8pm–5am390 flights49.0%
Scale runs 40% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 49.0% on time, against 82.7% 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 8am–11am window is the busiest, with 394 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 37 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 46.9% on time, 37 points below January, the best at 83.6%. 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 159 flights.
Across the week, Wednesday is the strongest day at 69.4% on time and Thursday the weakest at 58.6%. 11 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 56% of the 29,000 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.
- 56%Late-arriving aircraft
- 37%Carrier
- 7%National Airspace System
- 1%Extreme weather
- 0%Security
56% 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 29,000 reported delay minutes here, that single category outweighs weather by 56 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 28,723 reported delay minutes.
The largest share of delay minutes, 37%, 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 11,000 of the 29,000 delay minutes reported here.
Cancellations are rare at 0.62%, 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.5% 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.
The 957 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 73.0% on time across 1,607 flights, 8 points above 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.
The sample behind these figures is 1,610 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in OAK after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 83.6% on time and June 46.9%, a swing of 37 points. If the dates move at all, move them out of June before you think about anything else. 1,600 completed flights over 12 months sit behind that.
Common questions
DEN to OAK questions
How often is DEN to OAK delayed?
About one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 34.9% of the 1,610 flights in this analysis, against 22.4% nationally. Delayed flights are late by roughly 50 minutes on average.
How reliable is DEN to OAK compared with the rest of the country?
65.1% of flights arrive on time here against a national 77.6%, a difference of 13 points against it. That is worth a C+ on this site's grading scale.
What time of day has the fewest delays on DEN to OAK?
The 8am–11am departure window is the strongest at 82.7% on time. The 8pm–5am window is the weakest at 49.0%, 34 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 DEN to OAK?
June is the weakest month at 46.9% on time, compared with 83.6% in January. Across the year that is 37 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
- OAK to DEN — the return legseparate record
- Denver International (DEN) delay statistics
- Oakland International (OAK) delay statistics
- DEN to PHX, a related route75.7%
- LAS to OAK, a related route71.6%
- DEN to SLC, a related route77.5%
- Southwest Airlines on-time record65.1%
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
Direction matters. DEN to OAK and OAK to DEN 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.