Flight number record
UA 1645
United Airlines · Cleveland to Houston
- Route
- CLE → IAH
- Departs
- 06:00
- Flights
- 361
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1645, check with United Airlines.
UA 1645 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 14 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 45 minutes. That rests on 361 flights, with a median arrival 19 minutes early.
Set against the rest of the country, UA 1645's record is 14 points better than the US average of 77.3%. That gap is worth roughly 141 fewer late arrivals for every thousand flights.
Key figures
On time
91.4%
Arrivals under 15 minutes late, of 361 completed flights
Avg delay
47 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
3.0%
National rate is 8.3%
These figures cover 361 flights between September 2025 and August 2026. The median arrival is 19 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 1645 flies
UA 1645 flies CLE to IAH without a single fixed slot. Its most common scheduled departure was 06:00, used on 146 of 361 flights, with 18:41 (64 flights) next.
- Departs 06:00146 flights40.4%
- Departs 18:4164 flights17.7%
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 06:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and UA 1645 runs 2 points better at 91.4%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
UA 1645 next to CLE to IAH
Every carrier on CLE to IAH combined arrived on time 90.8% of the time across 814 flights, so UA 1645 is about level with it. Across its whole network United Airlines managed 78.8%, which this flight beats by 13 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1645thin sample | 361 | 91.4% | 47 min | 0.00% | A+ |
| All United Airlines on CLE–IAH | 814 | 90.8% | 63 min | 0.00% | A+ |
| All carriers on CLE–IAH | 814 | 90.8% | 63 min | 0.00% | A+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1645 quarter by quarter
UA 1645 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 87.1%, a swing of 13 points on roughly 72 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 flights87.9%
- Jan–Mar 202688 flights96.6%
- Apr–Jun 202690 flights90.0%
- Jul–Sep 202662 flights87.1%
Scale runs 80% to 100%.
By weekday, UA 1645 ranged from 88.0% on Thursday to 96.1% on Wednesday. With about 52 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late UA 1645 runs when it is late
UA 1645 often beats the schedule: 221 of 361 completed flights, 61%, arrived 15 minutes or more early. Most of the lateness is short. 16 of the 31 late arrivals were under half an hour behind, and 11 reached an hour or more. Not one arrived two hours late.
- 15+ min early221 flights61.2%
- Within 15 min109 flights30.2%
- 15–29 min late16 flights4.4%
- 30–59 min late4 flights1.1%
- 1–2 hours late11 flights3.0%
- 2+ hours late0 flights0.0%
Scale runs 0% to 100%.
Share of 361 completed flights by arrival against schedule.
A late pushback is often recovered here: of 26 departures that left 15 minutes late or more, 8 still arrived on time. 13 flights left on time and still arrived late.
The worst days
Worst days for UA 1645
The latest arrival of the period was on 14 February 2026, 1 hour 57 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 14 February 2026 | 1 hour 57 minutes | National Airspace System |
| 19 June 2026 | 1 hour 50 minutes | Carrier |
| 25 October 2025 | 1 hour 49 minutes | Carrier |
| 19 July 2026 | 1 hour 43 minutes | Late-arriving aircraft |
| 6 August 2026 | 1 hour 42 minutes | Carrier |
Delay causes
Why UA 1645 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 1,445 reported delay minutes.
- 37%National Airspace System
- 35%Carrier
- 27%Late-arriving aircraft
The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 512 of the 1,445 delay minutes reported here. The split is drawn from 1,445 delay minutes reported on UA 1645.
Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are 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 3.0% 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.
The 1,091 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The same number turns up on two other city pairs in the data, including BUR to SFO (1) and TVC to ORD (1), but none flew often enough under UA 1645 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to CLE to IAH only.
One caution: this is a thin sample. 361 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 1645
For a booking, UA 1645 has one of the better records a US domestic flight can show: 91.4% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- CLE to IAH, every carrier and departure
- IAH to CLE, the return direction
- United Airlines 1545 on the same route89.3%
- Cleveland Hopkins International (CLE) 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
- The best time of day to fly, according to 7.05 million flight records
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.