Route reliability record

SJC→PHX

San Jose to Phoenix

Flights: 3,031
Period: July 2025 to June 2026
Distance: 621 mi
Carriers: 4

This route lands a B+, 4 points better than the national rate of 77.6%. About one flight in six arrive 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 3,031 flights, of which American Airlines flew 639 at 87.5% on time.

Set against the rest of the country, this route's record is 4 points better than the US average of 77.6%. That gap is worth roughly 44 fewer late arrivals for every thousand flights.

On time

82.0%

Arrivals under 15 minutes late, of 3,007 completed flights

Avg delay

59 min

Across delayed arrivals only, not all flights

Cancelled

0.73%

National rate is 1.81%

Best carrier

American

87.5% on time across 639 flights

These figures cover 3,031 flights between July 2025 and June 2026. The median arrival is 5 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 SJC to PHX

The choice of carrier is not cosmetic here. American Airlines arrives on time 87.5% of the time; Southwest Airlines manages 78.6%. Sample sizes sit next to every figure, because a two-point gap across 1,879 flights means less than a ten-point one.

On-time performance by carrier on SJC to PHX
Airline	Flights	On time	Avg delay	Cancelled	Grade
Envoy Airthin sample	220	89.9%	50 min	0.91%	A+
American Airlines	639	87.5%	102 min	0.78%	A+
SkyWest Airlinesthin sample	293	85.5%	97 min	1.02%	A
Southwest Airlines	1,879	78.6%	48 min	0.64%	B+

American leads Southwest by 9 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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 27 points, against 9 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am679 flights92.7%
8am–11am554 flights92.2%
11am–2pm531 flights81.7%
2pm–5pm546 flights70.7%
5pm–8pm520 flights75.2%
8pm–5am201 flights65.8%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.7% of the time, against 65.8% for the overnight window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 679 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 18 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.

Darker means more delays. Figures are on-time percentages.January best, June worst

June is the worst month at 71.2% on time, 18 points below January, the best at 88.8%. 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. March was the busiest month here, with 300 flights.

Across the week, Saturday is the strongest day at 87.3% on time and Sunday the weakest at 77.8%. 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. Late-arriving aircraft accounts for 59% of the 32,000 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.

Late-arriving aircraft
59%
Carrier
28%
National Airspace System
11%
Extreme weather
3%

59% 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 32,000 reported delay minutes here, that single category outweighs weather by 23 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 32,169 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 92.7% on time here.

Cancellations are rare at 0.73%, 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

5.0% 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 are the about an hour kind, which a normal layover absorbs.

The 621 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 79.0% on time across 3,016 flights, 3 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 3 points of difference.

The sample behind these figures is 3,031 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.

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 88.8% on time and June 71.2%, a swing of 18 points. If the dates move at all, move them out of June before you think about anything else. 3,007 completed flights over 12 months sit behind that.

Common questions

SJC to PHX questions

How often is SJC to PHX delayed?

About one flight in six arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 18.0% of the 3,031 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on SJC to PHX?

American Airlines leads at 87.5% on time across 639 flights. Southwest Airlines is at the other end on 78.6%, a gap of 9 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 SJC to PHX?

The 5am–8am departure window is the strongest at 92.7% on time. The 8pm–5am window is the weakest at 65.8%, 27 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 SJC to PHX?

June is the weakest month at 71.2% on time, compared with 88.8% in January. Across the year that is 18 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. SJC to PHX and PHX to SJC are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures