Carrier route record

WNSAN→RNO

Southwest Airlines · San Diego to Reno

Flights: 924
Period: July 2025 to June 2026
Share of route: 80%
Carriers: 3

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

Southwest on SAN to RNO sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land about 50 minutes behind schedule. That rests on 924 flights, with a median arrival 4 minutes early.

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

On time

74.2%

Arrivals under 15 minutes late, of 916 completed flights

Avg delay

50 min

Across delayed arrivals only, not all flights

Cancelled

0.76%

National rate is 1.81%

Whole route

76.8%

Every carrier on SAN to RNO, 1,161 flights

These figures cover 924 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

Southwest against every carrier on SAN to RNO

Southwest flew 924 of the 1,161 flights on SAN to RNO, most of the route. Its 74.2% on time is 3 points worse than the route as a whole, which runs 76.8%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Spirit at 100.0% to Southwest at 74.2%. Two 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 RNO
Airline	Flights	On time	Avg delay	Cancelled	Grade
Spirit Airlinesthin sample	9	100.0%	—	0.00%	A+
SkyWest Airlinesthin sample	228	86.6%	54 min	4.82%	A−
Southwest Airlines (this page)	924	74.2%	50 min	0.76%	C+

Departure window

When Southwest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 38 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–8am27 flights—
8am–11am320 flights89.9%
11am–2pm18 flights—
2pm–5pm153 flights52.0%
5pm–8pm158 flights73.1%
8pm–5am248 flights65.0%

Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 89.9% of the time, against 52.0% for the afternoon window. That is 38 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 320 flights scheduled in it.

Across the year

Southwest on SAN to RNO through the year

Darker means more delays. Figures are on-time percentages.February best, June worst

June is the worst month at 57.4% on time, 31 points below February, the best at 88.4%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. June was the busiest month here, with 96 flights.

Across the week, Saturday is the strongest day at 89.4% on time and Thursday the weakest at 62.4%. 27 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Southwest runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 73% of the 12,000 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.

Late-arriving aircraft
73%
Carrier
20%
National Airspace System
6%
Security
1%

73% 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 12,000 reported delay minutes here, that single category outweighs weather by 73 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 11,901 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 89.9% on time here.

Cancellations are rare at 0.76%, 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 costs

5.7% 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 about 50 minutes, which a normal layover absorbs.

At 488 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 8am–11am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 71.2% on time across 924 flights, 3 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 3 points of difference.

One caution: this is a thin sample. 924 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 Southwest on SAN to RNO

Put together: treat all of this as provisional. 924 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 74.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 916 completed flights over 12 months sit behind that.

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.

Key figures