Route reliability record
GEG→SFO
Spokane to San Francisco
- Flights
- 873
- Period
- July 2025 to June 2026
- Distance
- 733 mi
- Carriers
- 2
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 77.6%. The late ones land a little over an hour behind schedule. That rests on 873 GEG to SFO flights, with a median arrival 4 minutes early.
Best time to fly GEG to SFO: a 2pm–5pm departure, ideally on a Saturday. Flights in that window arrived on time 80.6% of the time and Saturday flights 83.8%, against 73.7% 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
73.7%
Arrivals under 15 minutes late, of 870 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
0.11%
National rate is 1.81%
Best carrier
SkyWest
73.8% on time across 821 flights
These figures cover 873 flights between July 2025 and June 2026. Beyond the headline rate, 9.7% 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 GEG to SFO
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 | 821 | 73.8% | 77 min | 0.12% | C+ |
| United Airlinesthin sample | 52 | 71.2% | 42 min | 0.00% | C+ |
Flight by flight
Flights on GEG to SFO
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 is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 873 flights.
- 5am–8am334 flights73.1%
- 8am–11am3 flights—
- 11am–2pm332 flights75.2%
- 2pm–5pm181 flights80.6%
- 5pm–8pm23 flights—
- 8pm–5am—
Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 2pm–5pm slot at 80.6% on time, ahead of 5am–8am at 73.1%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5am–8am window is the busiest, with 334 flights scheduled in it.
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.
Delays peak in April, when the on-time rate falls to 50.8%. December is the strongest month at 85.5%. Moving a flexible trip across that boundary buys 35 points. June was the busiest month here, with 98 flights.
Across the week, Saturday is the strongest day at 83.8% on time and Sunday the weakest at 67.7%. 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. National Airspace System accounts for 49% of the 17,000 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.
- 49%National Airspace System
- 23%Carrier
- 19%Late-arriving aircraft
- 9%Extreme weather
49% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 8,320 minutes out of 17,000, against a national NAS share of 21%. The split is drawn from 17,085 reported delay minutes.
Cancellations are rare at 0.11%, 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. 9.7% 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 733 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 runs 76.0% on time across 867 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 873 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in SFO after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 873 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 73.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 870 completed flights over 12 months sit behind that.
Common questions
GEG to SFO questions
How often is GEG to SFO 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 26.3% of the 873 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is GEG to SFO compared with the rest of the country?
73.7% of flights arrive on time here against a national 77.6%, a difference of 4 points against it. That is worth a C+ on this site's grading scale.
What time of day has the fewest delays on GEG to SFO?
The 2pm–5pm departure window is the strongest at 80.6% on time. The 5am–8am window is the weakest at 73.1%, 8 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 April delays on GEG to SFO?
April is the weakest month at 50.8% on time, compared with 85.5% in December. 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
- SFO to GEG — the return legseparate record
- San Francisco International (SFO) delay statistics
- GEG to SEA, a related route85.9%
- LAX to SFO, a related route64.8%
- GEG to DEN, a related route83.8%
- SkyWest Airlines on-time record73.8%
- United Airlines on-time record71.2%
- How often a connection fails at the major US hubs
- Connecting flights: how much buffer the data says you need
Direction matters. GEG to SFO and SFO to GEG are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Embed GEG to SFO’s on-time badge on your site
Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.
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.