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DelayAtlas

Carrier route record

OOSANSTS

SkyWest Airlines · San Diego to Santa Rosa

Flights
827
Period
July 2025 to June 2026
Share of route
86%
Carriers
2
B−GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with SkyWest Airlines.

SkyWest on SAN to STS carries a cancellation problem, not just a delay problem: 3.4% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about four flights in five arrive on time, worth a B− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 827 flights, with a median arrival 9 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate SkyWest on SAN to STS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

80.3%

Arrivals under 15 minutes late, of 793 completed flights

Avg delay

48 min

Across delayed arrivals only, not all flights

Cancelled

3.39%

National rate is 1.81%

Whole route

78.8%

Every carrier on SAN to STS, 960 flights

These figures cover 827 flights between July 2025 and June 2026. The median arrival is 9 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

SkyWest against every carrier on SAN to STS

SkyWest flew 827 of the 960 flights on SAN to STS, most of the route. Its 80.3% on time is 2 points better than the route as a whole, which runs 78.8%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from SkyWest at 80.3% to Southwest at 69.7%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

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.

On-time performance by carrier on SAN to STS
AirlineFlightsOn timeAvg delayCancelledGrade
SkyWest Airlines (this page)82780.3%48 min3.39%B−
Southwest Airlinesthin sample13369.7%45 min0.75%C+

Flight by flight

SkyWest flight numbers on SAN to STS

Departure window

When SkyWest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 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–8am45 flights86.7%
  • 8am–11am234 flights82.8%
  • 11am–2pm171 flights72.8%
  • 2pm–5pm31 flights71.0%
  • 5pm–8pm58 flights89.5%
  • 8pm–5am288 flights81.1%

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is the strongest at 89.5% on time. The full set of windows spans 19 points.

Across the year

SkyWest on SAN to STS through the year

On-time rate by calendar month83J77F85M91A86M87J79J79A80S79O73N60D
Darker means more delays. Figures are on-time percentages.April best, December worst

December is the weak month at 59.6% on time, against 90.7% in April. 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. November was the busiest month here, with 87 flights.

Across the week, Wednesday is the strongest day at 90.7% on time and Friday the weakest at 65.8%. 25 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week80.5Mon86.3Tue90.7Wed85.7Thu65.8Fri85.7Sat71.0Sun
Monday: 80.5 percent on time. Tuesday: 86.3 percent on time. Wednesday: 90.7 percent on time. Thursday: 85.7 percent on time. Friday: 65.8 percent on time. Saturday: 85.7 percent on time. Sunday: 71.0 percent on time

Delay causes

Why SkyWest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 7,493 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
    44%
  • National Airspace System
    32%
  • Carrier
    20%
  • Extreme weather
    4%

44% 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 7,493 reported delay minutes here, that single category outweighs weather by 11 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 7,493 reported delay minutes.

32% 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 2,414 minutes out of 7,493, against a national NAS share of 21%.

Cancellations run at 3.39%, against 1.81% nationally. That is about one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

Badly late arrivals are rare here: only 4.7% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 508 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 75.4% on time across 827 flights, 5 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 5 points of difference.

One caution: this is a thin sample. 827 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.

What to do with this

Booking SkyWest on SAN to STS

Put together: the delay figures matter less here than the 3.39% cancellation rate. A late arrival costs you roughly 50 minutes; a cancelled flight costs you the day. Book the 5pm–8pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 793 completed flights over 12 months sit behind that.

Related

Where to go next

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.