Route reliability record
SAN→SMF
San Diego to Sacramento
- Flights
- 5,176
- Period
- June 2025 to May 2026
- Distance
- 480 mi
- Carriers
- 3
This route lands a B+, level with the national rate of 77.4%. Roughly one flight in four arrive 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 5,176 flights, of which SkyWest Airlines flew 1,194 at 78.4% on time.
The US average over the same twelve months is 77.4%, 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
77.0%
Arrivals under 15 minutes late, of 5,128 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
0.87%
National rate is 1.80%
Best carrier
SkyWest
78.4% on time across 1,194 flights
These figures cover 5,176 flights between June 2025 and May 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 SAN to SMF
The two carriers here are closely matched: 2 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlinesthin sample | 164 | 79.9% | 44 min | 3.05% | B− |
| SkyWest Airlines | 1,194 | 78.4% | 49 min | 1.42% | B |
| Southwest Airlines | 3,818 | 76.4% | 49 min | 0.60% | B+ |
No carrier stands out. SkyWest tops the table at 78.4%, 2 points clear of the bottom, which is inside the range this kind of sample moves year to year.
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 28 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am471 flights95.9%
- 8am–11am1,203 flights87.6%
- 11am–2pm973 flights74.8%
- 2pm–5pm778 flights70.5%
- 5pm–8pm1,046 flights68.9%
- 8pm–5am705 flights68.1%
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 95.9% of the time, against 68.1% for the overnight window. That is 28 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on.
Across the year
When delays peak on this route
This route's year swings by 12 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.
December is the weak month at 70.3% on time, against 82.4% in January. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days.
Across the week, Tuesday is the strongest day at 86.0% on time and Friday the weakest at 70.5%. 16 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 69% of the 57,000 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.
- 69%Late-arriving aircraft
- 20%Carrier
- 9%National Airspace System
- 1%Extreme weather
- 1%Security
69% 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 57,000 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 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 95.9% on time here.
Cancellations are rare at 0.87%, below the national 1.80% 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
5.8% of arrivals land an hour or more late, close to the national 8.2%. 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 roughly 50 minutes kind, which a normal layover absorbs.
At 480 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 runs 74.1% on time across 5,182 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 5,176 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 82.4% on time and December 70.3%, a swing of 12 points. If the dates move at all, move them out of December before you think about anything else.
Common questions
SAN to SMF questions
How often is SAN to SMF delayed?
Roughly one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.0% of the 5,176 flights in this analysis, against 22.6% nationally. Delayed flights are late by roughly 50 minutes on average.
Which airline is most reliable on SAN to SMF?
SkyWest Airlines leads at 78.4% on time across 1,194 flights. Southwest Airlines is at the other end on 76.4%, a gap of 2 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 SAN to SMF?
The 5am–8am departure window is the strongest at 95.9% on time. The 8pm–5am window is the weakest at 68.1%, 28 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 December delays on SAN to SMF?
December is the weakest month at 70.3% on time, compared with 82.4% in January. Across the year that is 12 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
- SMF to SAN — the return legseparate record
- San Diego International (SAN) delay statistics
- Sacramento International (SMF) delay statistics
- Alaska Airlines on-time record79.9%
- SkyWest Airlines on-time record78.4%
- Southwest Airlines on-time record76.4%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. SAN to SMF and SMF to SAN 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, June 2025 to May 2026. Updated monthly. How this data is collected.