Route on-time record

DEN to SAN: most on-time flights and the best time to fly

Denver (Denver International Airport) to San Diego (San Diego International Airport). 5,882 nonstop flights in Jun 2025 to May 2026, 76% arrived within 15 minutes and 0.7% were cancelled. The most reliable flight number was Alaska 220 at 7:25 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

DEN → SAN

Denver to San Diego: 5,882 nonstop flights a year

On time (12 months)

76%

Cancelled

0.7%

avg delay 15 min

Best time to leave

Before 9 AM

90% on time vs 62% 6 to 9 PM

Most reliable airline

United

80% chance on time

Check DEN to SAN fares

Lowest nonstop fare seen in the next two months: $67 (Frontier 2711 on 2026-11-15). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

#1 · Alaska 220
7:25 AM → 9:06 AM2h 41m nonstop
Local times, typical schedule. Last flown 2026-04-21.
94%
chance on time
On time (history)
100%
Cancelled
0.0%
Avg arrival delay
1 min
- Arrived on time 100% of the time (34 flights, Jun 2025 to May 2026).
- Never cancelled in 34 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 62%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Limited track record · 34 flights
Find Alaska 220 fares Opens this date on Aviasales
#2 · United 2309
7:45 AM → 9:16 AM2h 31m nonstop
Local times, typical schedule. Last flown 2026-05-31.
91%
chance on time
On time (history)
91%
Cancelled
0.3%
Avg arrival delay
5 min
- Arrived on time 91% of the time (341 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 62%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
- Lands inside SAN's trouble window: 66% of its 164 ground stops and delay programs started between 6 AM and noon.
Strong track record · 341 flights
Find United 2309 fares Opens this date on Aviasales
#3 · SkyWest 3021 · sold as United Express, Delta Connection, American Eagle or Alaska
7:40 AM → 9:34 AM2h 54m nonstop
Local times, typical schedule. Last flown 2026-03-17.
90%
chance on time
On time (history)
93%
Cancelled
0.0%
Avg arrival delay
3 min
- Arrived on time 93% of the time (85 flights, Jun 2025 to May 2026).
- Never cancelled in 85 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 62%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Moderate track record · 85 flights
Find 7:40 AM flight fares Opens this date on Aviasales
#4 · Southwest 2742
5:35 AM → 7:15 AM2h 40m nonstop
Local times, typical schedule. Last flown 2026-04-06.
88%
chance on time
On time (history)
100%
Cancelled
0.0%
Avg arrival delay
0 min
- Arrived on time 100% of the time (33 flights, Jun 2025 to May 2026).
- Never cancelled in 33 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 62%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Limited track record · 33 flights
Find Southwest 2742 fares Opens this date on Aviasales
#5 · Frontier 2421
7:12 AM → 8:42 AM2h 30m nonstop
Local times, typical schedule. Last flown 2026-05-31.
87%
chance on time
On time (history)
87%
Cancelled
2.5%
Avg arrival delay
6 min
- Arrived on time 87% of the time (39 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 62%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
- Lands inside SAN's trouble window: 66% of its 164 ground stops and delay programs started between 6 AM and noon.
Limited track record · 39 flights
Find Frontier 2421 fares Opens this date on Aviasales
#6 · United 1302
1:26 PM → 2:57 PM2h 31m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
On time (history)
87%
Cancelled
0.9%
Avg arrival delay
10 min
- Arrived on time 87% of the time (341 flights, Jun 2025 to May 2026).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Strong track record · 341 flights
Find United 1302 fares Opens this date on Aviasales
#7 · Southwest 176
6:45 AM → 8:10 AM2h 25m nonstop
Local times, typical schedule. Last flown 2026-05-31.
85%
chance on time
On time (history)
91%
Cancelled
0.0%
Avg arrival delay
5 min
- Arrived on time 91% of the time (46 flights, Jun 2025 to May 2026).
- Never cancelled in 46 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 62%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Limited track record · 46 flights
Find Southwest 176 fares Opens this date on Aviasales
#8 · Alaska 1491
1:16 PM → 2:52 PM2h 36m nonstop
Local times, typical schedule. Last flown 2026-05-12.
85%
chance on time
On time (history)
90%
Cancelled
2.0%
Avg arrival delay
11 min
- Arrived on time 90% of the time (149 flights, Jun 2025 to May 2026).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
- 69% of its delay minutes came from the plane arriving late from an earlier flight.
Moderate track record · 149 flights
Find Alaska 1491 fares Opens this date on Aviasales
#9 · United 1281
3:45 PM → 5:16 PM2h 31m nonstop
Local times, typical schedule. Last flown 2026-05-31.
84%
chance on time
On time (history)
85%
Cancelled
0.6%
Avg arrival delay
11 min
- Arrived on time 85% of the time (306 flights, Jun 2025 to May 2026).
- Departs inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
Strong track record · 306 flights
Find United 1281 fares Opens this date on Aviasales
#10 · Frontier 2817
6:52 PM → 8:33 PM2h 41m nonstop
Local times, typical schedule. Last flown 2026-05-02.
83%
chance on time
On time (history)
85%
Cancelled
0.9%
Avg arrival delay
10 min
- Arrived on time 85% of the time (226 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 62% on time; Before 9 AM: 90%).
- Departs inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
Strong track record · 226 flights
Find Frontier 2817 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

United Airlines80%
2,090 flights · 80% on time as flown · 0.5% cancel
Frontier Airlines78%
717 flights · 78% on time as flown · 0.8% cancel
Alaska Airlines78%
391 flights · 83% on time as flown · 1.1% cancel
SkyWest Airlines (sold as United Express, Delta Connection, American Eagle or Alaska)75%
295 flights · 78% on time as flown · 0.9% cancel
Southwest Airlines70%
2,389 flights · 70% on time as flown · 0.6% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

Before 9 AM90%
1,300 flights · avg delay 5 min
9 AM to noon79%
892 flights · avg delay 12 min
Noon to 3 PM82%
906 flights · avg delay 12 min
3 to 6 PM72%
829 flights · avg delay 18 min
6 to 9 PM62%
1,317 flights · avg delay 23 min
After 9 PM67%
638 flights · avg delay 22 min

Best day: Tuesday (80%). Worst: Friday (72%).

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

What delays this route

Late-arriving aircraft44%
Airline (crew, maintenance, boarding)32%
Air traffic control and airport volume23%
Severe weather1%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

DEN to SAN questions

What time of day is best to fly DEN to SAN?: Before 9 AM: 90% of flights arrived on time, against 62% for departures 6 to 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from DEN to SAN?: United, with a season-adjusted 80% chance of operating and arriving on time over 2,090 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on DEN to SAN?: July (64% on time); the best was November (82%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?: No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

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