Flight number record
UA 1645
United Airlines · Cleveland to Houston
- Route
- CLE → IAH
- Departs
- 06:00
- Flights
- 361
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 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 15 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 40 minutes. That rests on 361 flights, with a median arrival 20 minutes early.
Set against the rest of the country, UA 1645's record is 15 points better than the US average of 77.6%. That gap is worth roughly 149 fewer late arrivals for every thousand flights.
Key figures
On time
92.5%
Arrivals under 15 minutes late, of 361 completed flights
Avg delay
42 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
1 hour+ late
1.7%
National rate is 8.1%
These figures cover 361 flights between July 2025 and June 2026. The median arrival is 20 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.
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 06:20 (84 flights) and 06:15 (38 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 06:00146 flights40.4%
- Departs 06:2084 flights23.3%
- Departs 06:1538 flights10.5%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
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 3 points better at 92.5%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
UA 1645 next to CLE to IAH
Every carrier on CLE to IAH combined arrived on time 90.0% of the time across 823 flights, so UA 1645 is 3 points ahead of it. Across its whole network United Airlines managed 79.0%, which this flight beats by 14 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1645thin sample | 361 | 92.5% | 42 min | 0.00% | A+ |
| All United Airlines on CLE–IAH | 823 | 90.0% | 58 min | 0.00% | A+ |
| All carriers on CLE–IAH | 823 | 90.0% | 58 min | 0.00% | A+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 1645 quarter by quarter
Quarter by quarter UA 1645 held fairly steady: 95.7% in Jul–Sep 2025, 87.9% in Oct–Dec 2025, 96.6% in Jan–Mar 2026 and 90.0% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202592 flights95.7%
- Oct–Dec 202591 flights87.9%
- Jan–Mar 202688 flights96.6%
- Apr–Jun 202690 flights90.0%
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1645 ranged from 88.5% on Saturday to 96.2% on Monday. 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.
Delay causes
Why UA 1645 runs late
One category carries most of the weight here. National Airspace System accounts for 52% of the 1,131 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.
- 52%National Airspace System
- 43%Carrier
- 4%Late-arriving aircraft
The largest share of delay minutes, 43%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 491 of the 1,131 delay minutes reported here. The split is drawn from 1,131 delay minutes reported on UA 1645.
Cancellations are rare at 0.00%, below the national 1.81% 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 1.7% land an hour or more behind schedule, against 8.1% 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
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: 92.5% 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 route89.0%
- 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
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.