ON TIMEBOARD

STS → PHX on time

Charles M. Schulz Sonoma (Santa Rosa, CA) to Phoenix Sky Harbor (Phoenix, AZ). Every scheduled flight, September 2025 to August 2026.

On time
75%
arrived < 15 min late
Cancelled
0.4%
693 flights
Typical arrival
−2 min
median vs schedule
When late
+70 min
average delay
Flights / day
2
1 airline

75% of flights from Santa Rosa to Phoenix arrived on time over the past 12 months. That is worse than the typical U.S. route. The 4 p.m. departures ran on time 80% of the time; the 1 p.m. ones 59%. 8% of flights arrived more than an hour late or not at all.

How late?

The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for STS → PHX: when a flight was late, it was under 45 minutes late 62% of the time. About 1 in 14 flights landed an hour or more late, and 1 in 116 three hours or more; 0.4% were cancelled outright.

Share of all 693 scheduled flights, past 12 months, by arrival time against schedule.

By airline

AirlineFlightsOn timeCancelledTypical arrival1h+ lateAvg when lateOperated by
American Airlines69375%0.4%−2 min7.1%+70 minEnvoy 58%, SkyWest 42%, American Airlines 0%

Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.

Best time of day to fly

On-time rate by scheduled departure hour (local time at STS). Delays build through the day as late planes knock on, so early flights usually do best.

40%70%100%noon departures: 76% on time (229 flights)7612p1 p.m. departures: 59% on time (132 flights)591p2 p.m. departures: too few flights (1 flights)2p3 p.m. departures: too few flights (1 flights)3p4 p.m. departures: 80% on time (329 flights)804p
STS → PHX, share of flights arriving on time, by departure hour. Hours with under 100 flights are greyed out.
82%+ on time76–82%68–76%under 68%too few flights

Last flight of the day

On STS → PHX, each airline's last flight of the day was cancelled 0.6% of the time, against 0.3% for its earlier flights (2.0× as often). It arrived 3+ hours late 0.6% of the time (earlier flights: 1.2%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.

AirlineLast departureLast: cancelledLast: 3h+ lateEarlier: cancelledNext morning
American Airlines4:12 p.m.0.6%0.6%0.3%first flight 1:00 p.m.

Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.

If you need to be in PHX tonight, book an earlier flight so there's a backup if it's cancelled.

By month

Each calendar month pooled over 2023–2026. Best: February (87%). Worst: July (65%).

40%70%100%Jan: 82% on time (133 flights)82JanFeb: 87% on time (128 flights)87FebMar: 81% on time (155 flights)81MarApr: 83% on time (173 flights)83AprMay: 78% on time (157 flights)78MayJun: 67% on time (150 flights)67JunJul: 65% on time (153 flights)65JulAug: 83% on time (155 flights)83AugSep: 85% on time (140 flights)85SepOct: 82% on time (150 flights)82OctNov: 80% on time (164 flights)80NovDec: 79% on time (165 flights)79Dec

By day of week

DayFlightsOn timeCancelled
Monday10668%0.9%
Tuesday92——
Wednesday95——
Thursday10078%0.0%
Friday10267%1.0%
Saturday94——
Sunday10474%0.0%

Why flights were late

Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.

Late inbound plane 64%Airline (crew, maintenance, ops) 19%Air traffic & airport (NAS) 14%Severe weather 3%

Cancellations: airline 1 · weather 1 · air traffic/airport 1

Month by month

Not enough months with data to draw a trend.

Questions

How often are flights from STS to PHX on time?

75% of 693 scheduled flights from Santa Rosa, CA to Phoenix, AZ arrived within 15 minutes of schedule between September 2025 and August 2026. 0.4% were cancelled.

What is the best time of day to fly STS to PHX?

Flights scheduled to leave at 4 p.m. were the most reliable (80% on time). The 1 p.m. departures were the least (59%).

What month has the most delays from STS to PHX?

July (65% on time). The best month is February (87%), over 2023–2026.

Is the last flight of the day from STS to PHX more likely to be cancelled?

Yes. Each airline's last STS–PHX flight of the day was cancelled 0.6% of the time over the past year, against 0.3% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.

Related

Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.