Route reliability record
SFO→SMF
San Francisco to Sacramento
- Flights
- 1,377
- Period
- July 2025 to June 2026
- Distance
- 86 mi
- Carriers
- 2
This route lands a B, about a point 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 1,377 SFO to SMF flights, with a median arrival 4 minutes early.
Best time to fly SFO to SMF: a 5pm–8pm departure, ideally on a Tuesday. Flights in that window arrived on time 83.5% of the time and Tuesday flights 86.7%, against 78.9% for the route overall.
The US average over the same twelve months is 77.6%, 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
78.9%
Arrivals under 15 minutes late, of 1,353 completed flights
Avg delay
77 min
Across delayed arrivals only, not all flights
Cancelled
1.67%
National rate is 1.81%
Best carrier
SkyWest
79.3% on time across 1,323 flights
These figures cover 1,377 flights between July 2025 and June 2026. The median arrival is 4 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 SFO to SMF
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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 1,323 | 79.3% | 79 min | 1.74% | B |
| United Airlinesthin sample | 54 | 68.5% | 46 min | 0.00% | C+ |
Flight by flight
Flights on SFO to SMF
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.
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 11 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–8am—
- 8am–11am362 flights82.4%
- 11am–2pm213 flights77.4%
- 2pm–5pm99 flights72.4%
- 5pm–8pm343 flights83.5%
- 8pm–5am360 flights73.7%
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is the strongest at 83.5% on time. The full set of windows spans 11 points.
Across the year
When delays peak on this route
This route's year swings by 14 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 72.8% on time, against 86.7% in August. 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. October was the busiest month here, with 144 flights.
Across the week, Tuesday is the strongest day at 86.7% on time and Thursday the weakest at 75.5%. 11 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 22,000 reported delay minutes.
- 31%Late-arriving aircraft
- 28%Carrier
- 24%National Airspace System
- 16%Extreme weather
Extreme weather accounts for 16% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.6 times the usual weather exposure. The split is drawn from 22,136 reported delay minutes.
Cancellations sit at 1.67% against a national 1.81%, which is ordinary. Diversions add another 0.07%.
Connections and stage length
What a delay here actually costs
7.2% 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 86 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 64.6% on time across 1,378 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.
The sample behind these figures is 1,377 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 SMF 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. August runs 86.7% on time and December 72.8%, a swing of 14 points. If the dates move at all, move them out of December before you think about anything else. 1,353 completed flights over 12 months sit behind that.
Common questions
SFO to SMF questions
How often is SFO to SMF delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.1% of the 1,377 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is SFO to SMF compared with the rest of the country?
78.9% of flights arrive on time here against a national 77.6%, a difference of about a point in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on SFO to SMF?
The 5pm–8pm departure window is the strongest at 83.5% on time. The 2pm–5pm window is the weakest at 72.4%, 11 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 SFO to SMF?
December is the weakest month at 72.8% on time, compared with 86.7% in August. Across the year that is 14 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 SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- Sacramento International (SMF) delay statistics
- SFO to LAX, a related route73.9%
- LAX to SMF, a related route84.6%
- SFO to SEA, a related route73.7%
- SkyWest Airlines on-time record79.3%
- United Airlines on-time record68.5%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. SFO to SMF and SMF to SFO 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.