Route on-time record

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

San Francisco (San Francisco International Airport) to Denver (Denver International Airport). 5,384 nonstop flights in Jun 2025 to May 2026, 76% arrived within 15 minutes and 0.5% were cancelled. The most reliable flight number was United 1233 at 6:15 AM.

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

SFO → DEN

San Francisco to Denver: 5,384 nonstop flights a year

On time (12 months)

76%

Cancelled

0.5%

avg delay 15 min

Best time to leave

Before 9 AM

90% on time vs 61% 3 to 6 PM

Most reliable airline

United

82% chance on time

Check SFO to DEN fares

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 · United 1233
6:15 AM → 9:59 AM2h 44m nonstop
Local times, typical schedule. Last flown 2026-05-31.
95%
chance on time
On time (history)
98%
Cancelled
0.0%
Avg arrival delay
1 min
- Arrived on time 98% of the time (47 flights, Jun 2025 to May 2026).
- Never cancelled in 47 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 3 to 6 PM: 61%).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Limited track record · 47 flights
Find United 1233 fares Opens this date on Aviasales
#2 · United 1315
6:45 AM → 10:33 AM2h 48m nonstop
Local times, typical schedule. Last flown 2026-05-20. Same departure also flew as United 2234; its record covers all of them.
94%
chance on time
On time (history)
96%
Cancelled
0.0%
Avg arrival delay
1 min
- Arrived on time 96% of the time (51 flights, Jun 2025 to May 2026).
- Never cancelled in 52 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 3 to 6 PM: 61%).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Limited track record · 51 flights
Find United 1315 fares Opens this date on Aviasales
#3 · United 1479
5:00 AM → 8:40 AM2h 40m nonstop
Local times, typical schedule. Last flown 2026-05-31.
94%
chance on time
On time (history)
94%
Cancelled
0.0%
Avg arrival delay
3 min
- Arrived on time 94% of the time (88 flights, Jun 2025 to May 2026).
- Never cancelled in 88 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 3 to 6 PM: 61%).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Moderate track record · 88 flights
Find United 1479 fares Opens this date on Aviasales
#4 · Southwest 321
5:25 AM → 9:00 AM2h 35m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 860; its record covers all of them.
92%
chance on time
On time (history)
95%
Cancelled
1.1%
Avg arrival delay
5 min
- Arrived on time 95% of the time (86 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 3 to 6 PM: 61%).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Moderate track record · 86 flights
Find Southwest 321 fares Opens this date on Aviasales
#5 · United 513
6:00 AM → 9:41 AM2h 41m nonstop
Local times, typical schedule. Last flown 2026-03-28.
90%
chance on time
On time (history)
91%
Cancelled
4.2%
Avg arrival delay
4 min
- Arrived on time 91% of the time (23 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 3 to 6 PM: 61%).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find United 513 fares Opens this date on Aviasales
#6 · United 2348
8:20 AM → 12:09 PM2h 49m nonstop
Local times, typical schedule. Last flown 2026-05-31.
88%
chance on time
On time (history)
88%
Cancelled
1.0%
Avg arrival delay
11 min
- Arrived on time 88% of the time (307 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 3 to 6 PM: 61%).
- Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
Strong track record · 307 flights
Find United 2348 fares Opens this date on Aviasales
#7 · United 301
8:53 PM → 12:45 AM2h 51m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
On time (history)
88%
Cancelled
0.0%
Avg arrival delay
7 min
- Arrived on time 88% of the time (146 flights, Jun 2025 to May 2026).
- Never cancelled in 146 scheduled flights.
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Moderate track record · 146 flights
Find United 301 fares Opens this date on Aviasales
#8 · United 2436
7:07 PM → 10:59 PM2h 52m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
On time (history)
90%
Cancelled
0.0%
Avg arrival delay
10 min
- Arrived on time 90% of the time (146 flights, Jun 2025 to May 2026).
- Never cancelled in 146 scheduled flights.
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
- 85% of its delay minutes came from the plane arriving late from an earlier flight.
Moderate track record · 146 flights
Find United 2436 fares Opens this date on Aviasales
#9 · Frontier 1230
6:00 AM → 9:47 AM2h 47m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
On time (history)
86%
Cancelled
1.2%
Avg arrival delay
10 min
- Arrived on time 86% of the time (339 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 3 to 6 PM: 61%).
- Departs outside SFO's trouble window (7 AM to 1 PM, when 61% of its 333 ground stops and delay programs started).
Strong track record · 339 flights
Find Frontier 1230 fares Opens this date on Aviasales
#10 · United 1023
8:45 AM → 12:28 PM2h 43m nonstop
Local times, typical schedule. Last flown 2026-03-28.
83%
chance on time
On time (history)
83%
Cancelled
0.0%
Avg arrival delay
15 min
- Arrived on time 83% of the time (24 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 3 to 6 PM: 61%).
- Departs inside SFO's trouble window: 61% of its 333 ground stops and delay programs started between 7 AM and 1 PM.
- Short track record (24 flights), so its score leans on the airline's record at this hour.
Limited track record · 24 flights
Find United 1023 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

United Airlines82%
3,364 flights · 82% on time as flown · 0.3% cancel
Frontier Airlines75%
565 flights · 76% on time as flown · 0.9% cancel
Southwest Airlines62%
1,455 flights · 62% on time as flown · 0.8% cancel

On time by departure time

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

Before 9 AM90%
2,053 flights · avg delay 7 min
9 AM to noon68%
549 flights · avg delay 17 min
Noon to 3 PM62%
1,213 flights · avg delay 22 min
3 to 6 PM61%
635 flights · avg delay 26 min
6 to 9 PM79%
770 flights · avg delay 15 min
After 9 PM74%
164 flights · avg delay 18 min

Best day: Tuesday (81%). Worst: Friday (74%).

Smarter routing

Nearby airports that run more on time

SJC → DEN 81% chance on time
Norman Y. Mineta San Jose International Airport to Denver International Airport · 2,594 flights a year · 30 mi from your airports · yours: 76%
Rank flights Fares

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 aircraft47%
Air traffic control and airport volume26%
Airline (crew, maintenance, boarding)26%
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

SFO to DEN questions

What time of day is best to fly SFO to DEN?: Before 9 AM: 90% of flights arrived on time, against 61% for departures 3 to 6 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 SFO to DEN?: United, with a season-adjusted 82% chance of operating and arriving on time over 3,364 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 SFO to DEN?: June (69% on time); the best was January (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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Live status: FAA delays and ground stops

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