Route reliability record
DEN→SJC
Denver to San Jose
- Flights
- 2,547
- Period
- September 2025 to August 2026
- Distance
- 948 mi
- Carriers
- 3
This route sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.3%. The late ones land roughly 55 minutes behind schedule. That rests on 2,547 DEN to SJC flights, of which United Airlines flew 990 at 81.6% on time.
Best time to fly DEN to SJC: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 88.7% of the time and Tuesday flights 77.5%, against 73.5% 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
73.5%
Arrivals under 15 minutes late, of 2,536 completed flights
Avg delay
54 min
Across delayed arrivals only, not all flights
Cancelled
0.43%
National rate is 1.89%
Best carrier
United
81.6% on time across 990 flights
These figures cover 2,547 flights between September 2025 and August 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
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Carrier by carrier
Which airline is most reliable on DEN to SJC
The choice of carrier is not cosmetic here. United Airlines arrives on time 81.6% of the time; Southwest Airlines manages 68.0%. Sample sizes sit next to every figure, because a two-point gap across 1,523 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 990 | 81.6% | 63 min | 0.00% | B+ |
| Frontier Airlinesthin sample | 34 | 79.4% | 29 min | 0.00% | B+ |
| Southwest Airlines | 1,523 | 68.0% | 51 min | 0.72% | C+ |
The spread between United and Southwest is 14 points, wide enough that it should decide the booking. On a hundred trips that is 14 more arrivals inside the on-time window.
Flight by flight
Flights on DEN to SJC
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Denver to San Jose
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. 3 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. DEN → MRYDenver to Monterey | SkyWest Airlines | 84.5% | 84.5% | 0.00% | 11am–2pm, Wed | OO 5438 11:15 |
| 2. DEN → SJCDenver to San Jose | United Airlines | 81.6% | 81.6% | 0.00% | 8am–11am, Sat | UA 2745 19:30 |
| 3. DEN → SFODenver to San Francisco | United Airlines | 68.8% | 69.0% | 0.23% | 5am–8am, Tue | UA 2367 05:15 |
| 4. DEN → SJCDenver to San Jose | Southwest Airlines | 67.5% | 68.0% | 0.72% | 8am–11am, Tue | — |
| 5. DEN → OAKDenver to Oakland | Southwest Airlines | 64.9% | 65.4% | 0.81% | 5am–8am, Sat | — |
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 14 points between the best and worst carrier.
- 5am–8am65 flights87.7%
- 8am–11am522 flights88.7%
- 11am–2pm626 flights78.7%
- 2pm–5pm423 flights70.7%
- 5pm–8pm569 flights65.1%
- 8pm–5am342 flights54.9%
Scale runs 45% to 95%.
The 8pm–5am window is where this operation falls apart: 54.9% on time, against 88.7% 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 11am–2pm window is the busiest, with 626 flights scheduled in it.
Explore
Filter DEN to SJC 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 DEN to SJC, the best departure window is 8am–11am at 88.7% on time and the worst is 8pm–5am at 54.9%, a wide gap of 33.8 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am87.7%
- 8–11am88.7%
- 11am–2pm78.7%
- 2–5pm70.7%
- 5–8pm65.1%
- 8pm–5am54.9%
best all US flightsScale 45% to 95%.
Across the year
When delays peak on this route
This route's year swings by 35 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 53.6% on time, 35 points below November, the best at 89.1%. 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. September was the busiest month here, with 264 flights.
Across the week, Tuesday is the strongest day at 77.5% on time and Monday the weakest at 69.6%, a spread of 8 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 57% of the 36,000 delay minutes carriers reported here, and the remaining four split what is left.
- 57%Late-arriving aircraft
- 32%Carrier
- 9%National Airspace System
- 1%Extreme weather
- 0%Security
57% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 36,000 reported delay minutes here, that single category outweighs weather by 57 to one. The split is drawn from 36,143 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 88.7% 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
7.8% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 55 minutes, which a normal layover absorbs.
The 948 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.
The return leg is a different operation and performs like one: it runs 80.6% on time across 2,546 flights, 7 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 7 points of difference.
The sample behind these figures is 2,547 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 SJC 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. November runs 89.1% on time and June 53.6%, a swing of 35 points. If the dates move at all, move them out of June before you think about anything else. 2,536 completed flights over 12 months sit behind that.
Common questions
DEN to SJC questions
How often is DEN to SJC 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 26.5% of the 2,547 flights in this analysis, against 22.7% nationally. Delayed flights are late by roughly 55 minutes on average.
Which airline is most reliable on DEN to SJC?
United Airlines leads at 81.6% on time across 990 flights. Southwest Airlines is at the other end on 68.0%, a gap of 14 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on DEN to SJC?
The 8am–11am departure window is the strongest at 88.7% on time. The 8pm–5am window is the weakest at 54.9%, 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 SJC?
June is the weakest month at 53.6% on time, compared with 89.1% in November. Across the year that is 35 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
- SJC to DEN — the return legseparate record
- Denver International (DEN) delay statistics
- Norman Y. Mineta San Jose International (SJC) delay statistics
- United Airlines on DEN to SJC81.6%
- Southwest Airlines on DEN to SJC68.0%
- DEN to PHX, a related route75.6%
- SAN to SJC, a related route74.5%
- DEN to SLC, a related route78.2%
- United Airlines on-time record81.6%
- Frontier Airlines on-time record79.4%
- Southwest Airlines on-time record68.0%
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
Direction matters. DEN to SJC and SJC 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.