Flight number record
UA 505
United Airlines · San Francisco to Houston
- Route
- SFO → IAH
- Departs
- 23:59
- Flights
- 327
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 505, check with United Airlines.
UA 505 lands a B+, 5 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 327 flights, with a median arrival 6 minutes early.
Set against the rest of the country, UA 505's record is 5 points better than the US average of 77.3%. That gap is worth roughly 49 fewer late arrivals for every thousand flights.
Key figures
On time
82.2%
Arrivals under 15 minutes late, of 325 completed flights
Avg delay
57 min
Across delayed arrivals only, not all flights
Cancelled
0.31%
National rate is 1.89%
1 hour+ late
4.6%
National rate is 8.3%
These figures cover 327 flights between September 2025 and August 2026. The median arrival is 6 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.
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Schedule
When UA 505 flies
UA 505 is scheduled to leave San Francisco (SFO) at 23:59 local time and reach Houston (IAH) at 05:46. That slot held for 327 of the 327 scheduled departures in the data, so the figures below describe one steady operation rather than a number that moved around the clock.
- Departs 23:59327 flights100.0%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 23:59 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and UA 505 runs 12 points better at 82.2%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
UA 505 next to SFO to IAH
Every carrier on SFO to IAH combined arrived on time 84.0% of the time across 3,578 flights, so UA 505 is 2 points behind it. Across its whole network United Airlines managed 78.8%, which this flight beats by 3 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 505thin sample | 327 | 82.2% | 57 min | 0.31% | B+ |
| All United Airlines on SFO–IAH | 3,578 | 84.0% | 50 min | 0.25% | B+ |
| All carriers on SFO–IAH | 3,578 | 84.0% | 50 min | 0.25% | B+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 505 quarter by quarter
UA 505 did not run the same all year. Its best quarter was Jul–Sep 2025 at 100.0% on time and its weakest Jul–Sep 2026 at 71.0%, a swing of 29 points on roughly 65 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights100.0%
- Oct–Dec 202591 flights81.3%
- Jan–Mar 202653 flights84.6%
- Apr–Jun 202691 flights83.3%
- Jul–Sep 202662 flights71.0%
Scale runs 65% to 100%.
By weekday, UA 505 did best on Tuesday at 91.1% on time and worst on Sunday at 78.7%. Each day rests on about 47 flights, so a gap of 12 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 505 runs when it is late
UA 505 often beats the schedule: 98 of 325 completed flights, 30%, arrived 15 minutes or more early. The 58 late arrivals split 21 under half an hour, 22 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early98 flights30.2%
- Within 15 min169 flights52.0%
- 15–29 min late21 flights6.5%
- 30–59 min late22 flights6.8%
- 1–2 hours late10 flights3.1%
- 2+ hours late5 flights1.5%
Scale runs 0% to 100%.
Share of 325 completed flights by arrival against schedule.
A late pushback is often recovered here: of 86 departures that left 15 minutes late or more, 34 still arrived on time. Only 6 left on time and still arrived late.
The worst days
Worst days for UA 505
The latest arrival of the period was on 14 March 2026, 4 hours 55 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 14 March 2026 | 4 hours 55 minutes | Carrier |
| 23 February 2026 | 4 hours 43 minutes | Late-arriving aircraft |
| 25 February 2026 | 4 hours 24 minutes | Carrier |
| 31 December 2025 | 3 hours 43 minutes | Carrier |
| 21 July 2026 | 2 hours 10 minutes | Late-arriving aircraft |
Delay causes
Why UA 505 runs late
Carrier accounts for 69% of the 3,288 delay minutes carriers reported here, and the remaining four split what is left.
- 69%Carrier
- 21%Late-arriving aircraft
- 8%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 69%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,262 of the 3,288 delay minutes reported here. The split is drawn from 3,288 delay minutes reported on UA 505.
Cancellations are rare at 0.31%, below the national 1.89% 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 routes
What a delay on this flight costs
Badly late arrivals are rare here: only 4.6% land an hour or more behind schedule, against 8.3% 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.
At 1,635 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The same number turns up on four other city pairs in the data, including SAN to SFO (108), PHX to ORD (37) and ORD to SFO (19), but none flew often enough under UA 505 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SFO to IAH only.
One caution: this is a thin sample. 327 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 UA 505
For a booking, read UA 505 as 82.2% on time with 0.31% cancelled over 327 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SFO to IAH, every carrier and departure
- IAH to SFO, the return direction
- United Airlines 2305 on the same route80.8%
- United Airlines 1387 on the same route75.4%
- San Francisco International (SFO) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Worst months to fly in the US, ranked by the data
A flight number here means United Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.