UK FLIGHT DELAY INDEX

derived from CAA punctuality statistics for UK reporting airports

How often are these flights late or cancelled?

Icelandair

In the twelve months from July 2025 to June 2026, 14.6% of 1,960 movements arriving into the UK were disrupted — more than fifteen minutes late or cancelled at short notice.

Put the other way round, 85.4% of 1,960 movements met the fifteen-minute convention. These are historical observations, not a forecast.

Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Source: CAA punctuality statistics · snapshot 17/08/2026 10:24 · method route-record-v2.1 · Versioned claims, formulas and entity mapping.

0 operations (0.00%) excluded because their published percentages could not be reconciled to whole numbers. Excluded operations enter neither the numerator nor the denominator. Outcome figures and comparisons are unavailable when the excluded share exceeds fifteen percent.

The four numbers at a glance

14.6% of 1,960 movements were disrupted over July 2025 to June 2026.

Average delay covers delayed movements only. Its range reflects rounded source means and the unknown count of exactly punctual movements.

DisruptionShort-notice cancellationsDelay among delayed movementsOver three hours
14.6% of 1,960 movements1.5% of 1,960 movements19.5–65.7 minutes; delayed denominator 258–7690.6% of 1,960 movements
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

When late, how late?

0.6% of 1,960 movements passed the three-hour mark.

The ladder shows how many movements crossed each threshold. Cancellations are separate: 1.5% of 1,960 movements.

DelayShare and sampleOne event per movements
More than 15 minutes13.2% of 1,960 movements7.6
More than 30 minutes6.2% of 1,960 movements16.2
More than 60 minutes2.4% of 1,960 movements40.8
More than 120 minutes0.8% of 1,960 movements122.5
More than 180 minutes0.6% of 1,960 movements178.2
More than 360 minutes0.2% of 1,960 movements490.0
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Slightly late or occasionally a disaster?

0.8% of 1,960 movements passed two hours.

The histogram shows the published delay bands. Bucket shares use all reported operations, including unmatched records; cancellations are reported separately.

Nine delay buckets, minutes; share of all recorded operations>15 early38719.7%15–1 early77539.5%0–15 late51126.1%16–301377.0%31–60733.7%61…120321.6%121…18050.3%181…36070.4%>36040.2%D=1,960
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Better or worse since the start of the archive?

Best month: Sep 2021, 3.9% of 77 movements. Worst month: Jun 2018, 65.2% of 141 movements.

The line traces every month. Lower disruption is better; gaps are never zeros. Pandemic readings describe a different operating regime.

Monthly disruption share; gaps mean no published dataJan 2018: 41.0%; sample: 1392018Feb 2018: 29.0%; sample: 131Mar 2018: 27.8%; sample: 158Apr 2018: 24.2%; sample: 153May 2018: 34.8%; sample: 141Jun 2018: 65.2%; sample: 141Jul 2018: 55.5%; sample: 146Aug 2018: 41.5%; sample: 147Sep 2018: 24.7%; sample: 158Oct 2018: 28.0%; sample: 164Nov 2018: 30.5%; sample: 154Dec 2018: 23.6%; sample: 148Jan 2019: 13.0%; sample: 1542019Feb 2019: 17.4%; sample: 138Mar 2019: 15.2%; sample: 151Apr 2019: 33.5%; sample: 155May 2019: 30.6%; sample: 144Jun 2019: 40.4%; sample: 136Jul 2019: 31.2%; sample: 138Aug 2019: 30.9%; sample: 136Sep 2019: 25.0%; sample: 136Oct 2019: 25.5%; sample: 161Nov 2019: 9.0%; sample: 144Dec 2019: 13.6%; sample: 140Jan 2020: 29.7%; sample: 1482020Feb 2020: 32.4%; sample: 139Mar 2020: 27.5%; sample: 109Apr 2020: suppressed: fewer than twenty movements×May 2020: suppressed: fewer than twenty movements×Jun 2020: suppressed: fewer than twenty movements×Jul 2020: suppressed: fewer than twenty movements×Aug 2020: suppressed: fewer than twenty movements×Sep 2020: suppressed: fewer than twenty movements×Oct 2020: suppressed: fewer than twenty movements×Nov 2020: suppressed: fewer than twenty movements×Dec 2020: suppressed: fewer than twenty movements×Jan 2021: suppressed: fewer than twenty movements×2021Feb 2021: suppressed: fewer than twenty movements×Mar 2021: suppressed: fewer than twenty movements×Apr 2021: suppressed: fewer than twenty movements×May 2021: suppressed: fewer than twenty movements×Jun 2021: 0.0%; sample: 29Jul 2021: 7.1%; sample: 42Aug 2021: 2.0%; sample: 49Sep 2021: 3.9%; sample: 77Oct 2021: 11.7%; sample: 77Nov 2021: 6.2%; sample: 64Dec 2021: 13.8%; sample: 58Jan 2022: 12.7%; sample: 552022Feb 2022: 15.5%; sample: 58Mar 2022: 19.0%; sample: 79Apr 2022: 8.7%; sample: 126May 2022: 19.3%; sample: 119Jun 2022: 38.2%; sample: 131Jul 2022: 40.1%; sample: 142Aug 2022: 33.6%; sample: 137Sep 2022: 25.0%; sample: 128Oct 2022: 21.5%; sample: 144Nov 2022: 14.4%; sample: 132Dec 2022: 37.6%; sample: 125Jan 2023: 23.9%; sample: 1342023Feb 2023: 23.7%; sample: 131Mar 2023: 13.6%; sample: 140Apr 2023: 20.3%; sample: 143May 2023: 20.1%; sample: 134Jun 2023: 43.9%; sample: 132Jul 2023: 31.2%; sample: 138Aug 2023: 23.4%; sample: 137Sep 2023: 29.5%; sample: 139Oct 2023: 24.2%; sample: 157Nov 2023: 7.9%; sample: 151Dec 2023: 27.1%; sample: 140Jan 2024: 11.5%; sample: 1312024Feb 2024: 13.3%; sample: 128Mar 2024: 6.8%; sample: 133Apr 2024: 12.0%; sample: 142May 2024: 19.7%; sample: 137Jun 2024: 13.4%; sample: 134Jul 2024: 24.6%; sample: 138Aug 2024: 21.5%; sample: 135Sep 2024: 17.4%; sample: 138Oct 2024: 21.8%; sample: 156Nov 2024: 14.0%; sample: 150Dec 2024: 37.8%; sample: 143Jan 2025: 28.9%; sample: 1492025Feb 2025: 22.0%; sample: 132Mar 2025: 12.6%; sample: 151Apr 2025: 7.2%; sample: 152May 2025: 20.2%; sample: 163Jun 2025: 7.8%; sample: 154Jul 2025: 17.4%; sample: 161Aug 2025: 18.1%; sample: 160Sep 2025: 11.8%; sample: 153Oct 2025: 17.2%; sample: 174Nov 2025: 9.0%; sample: 167Dec 2025: 18.8%; sample: 160Jan 2026: 12.3%; sample: 1632026Feb 2026: 7.2%; sample: 152Mar 2026: 20.5%; sample: 171Apr 2026: 18.3%; sample: 164May 2026: 10.7%; sample: 169Jun 2026: 13.9%; sample: 166Pandemic regime Jun 2020Summer 2022 breakdown Jul 2022NATS system failure Aug 2023Heathrow fire closure Mar 2025100%0%
Every monthly observation
MonthDisruption on arrivals
Jan 201841.0% of 139 movements
Feb 201829.0% of 131 movements
Mar 201827.8% of 158 movements
Apr 201824.2% of 153 movements
May 201834.8% of 141 movements
Jun 201865.2% of 141 movements
Jul 201855.5% of 146 movements
Aug 201841.5% of 147 movements
Sep 201824.7% of 158 movements
Oct 201828.0% of 164 movements
Nov 201830.5% of 154 movements
Dec 201823.6% of 148 movements
Jan 201913.0% of 154 movements
Feb 201917.4% of 138 movements
Mar 201915.2% of 151 movements
Apr 201933.5% of 155 movements
May 201930.6% of 144 movements
Jun 201940.4% of 136 movements
Jul 201931.2% of 138 movements
Aug 201930.9% of 136 movements
Sep 201925.0% of 136 movements
Oct 201925.5% of 161 movements
Nov 20199.0% of 144 movements
Dec 201913.6% of 140 movements
Jan 202029.7% of 148 movements
Feb 202032.4% of 139 movements
Mar 202027.5% of 109 movements
Apr 2020suppressed: fewer than twenty movements
May 2020suppressed: fewer than twenty movements
Jun 2020suppressed: fewer than twenty movements
Jul 2020suppressed: fewer than twenty movements
Aug 2020suppressed: fewer than twenty movements
Sep 2020suppressed: fewer than twenty movements
Oct 2020suppressed: fewer than twenty movements
Nov 2020suppressed: fewer than twenty movements
Dec 2020suppressed: fewer than twenty movements
Jan 2021suppressed: fewer than twenty movements
Feb 2021suppressed: fewer than twenty movements
Mar 2021suppressed: fewer than twenty movements
Apr 2021suppressed: fewer than twenty movements
May 2021suppressed: fewer than twenty movements
Jun 2021no events in 29 movements — small sample, not ranked
Jul 20217.1% of 42 movements — small sample, not ranked
Aug 20212.0% of 49 movements — small sample, not ranked
Sep 20213.9% of 77 movements
Oct 202111.7% of 77 movements
Nov 20216.2% of 64 movements
Dec 202113.8% of 58 movements
Jan 202212.7% of 55 movements
Feb 202215.5% of 58 movements
Mar 202219.0% of 79 movements
Apr 20228.7% of 126 movements
May 202219.3% of 119 movements
Jun 202238.2% of 131 movements
Jul 202240.1% of 142 movements
Aug 202233.6% of 137 movements
Sep 202225.0% of 128 movements
Oct 202221.5% of 144 movements
Nov 202214.4% of 132 movements
Dec 202237.6% of 125 movements
Jan 202323.9% of 134 movements
Feb 202323.7% of 131 movements
Mar 202313.6% of 140 movements
Apr 202320.3% of 143 movements
May 202320.1% of 134 movements
Jun 202343.9% of 132 movements
Jul 202331.2% of 138 movements
Aug 202323.4% of 137 movements
Sep 202329.5% of 139 movements
Oct 202324.2% of 157 movements
Nov 20237.9% of 151 movements
Dec 202327.1% of 140 movements
Jan 202411.5% of 131 movements
Feb 202413.3% of 128 movements
Mar 20246.8% of 133 movements
Apr 202412.0% of 142 movements
May 202419.7% of 137 movements
Jun 202413.4% of 134 movements
Jul 202424.6% of 138 movements
Aug 202421.5% of 135 movements
Sep 202417.4% of 138 movements
Oct 202421.8% of 156 movements
Nov 202414.0% of 150 movements
Dec 202437.8% of 143 movements
Jan 202528.9% of 149 movements
Feb 202522.0% of 132 movements
Mar 202512.6% of 151 movements
Apr 20257.2% of 152 movements
May 202520.2% of 163 movements
Jun 20257.8% of 154 movements
Jul 202517.4% of 161 movements
Aug 202518.1% of 160 movements
Sep 202511.8% of 153 movements
Oct 202517.2% of 174 movements
Nov 20259.0% of 167 movements
Dec 202518.8% of 160 movements
Jan 202612.3% of 163 movements
Feb 20267.2% of 152 movements
Mar 202620.5% of 171 movements
Apr 202618.3% of 164 movements
May 202610.7% of 169 movements
Jun 202613.9% of 166 movements
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

What did the big disruptions do here?

Each event is compared with the twelve preceding calendar months and the first later return to baseline.

A worse month is not proof the named event caused it. The open data carry no delay-cause field. Recovery is observed for at most eight subsequent months.

EventDirectionDisruption that monthBaseline beforeReturn to baseline
Pandemic regime · Jun 2020Arrivalssuppressed: fewer than twenty movementsno complete baselinenot enough data: needs a complete baseline and a publishable event month
Pandemic regime · Jun 2020Departuressuppressed: fewer than twenty movementsno complete baselinenot enough data: needs a complete baseline and a publishable event month
Summer 2022 breakdown · Jul 2022Arrivals40.1% of 142 movements13.2% across 935 flightsstill above it 8 months later
Summer 2022 breakdown · Jul 2022Departures60.6% of 142 movements21.2% across 936 flightsreturned after 4 months
NATS system failure · Aug 2023Arrivals23.4% of 137 movements25.7% across 1,618 flightsreturned after 2 months
NATS system failure · Aug 2023Departures45.3% of 137 movements34.3% across 1,619 flightsreturned the next month
Heathrow fire closure · Mar 2025Arrivals12.6% of 151 movements20.0% across 1,687 flightsreturned the next month
Heathrow fire closure · Mar 2025Departures10.6% of 151 movements25.9% across 1,688 flightsreturned the next month
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Which time of year has been hardest?

Highest median: Jun, 38.2% across 7 months. Lowest median: Nov, 11.5% across 6 months.

Even the same calendar month differs across years. This is a record, not a forecast; pandemic years are excluded from the summaries.

Each cell is one calendar month of one year; the number is the share of that month’s arrivals that were disrupted. Darker means worse. A blank cell means no published data, not zero.

Seasonality: calendar month by year; share and nJanFebMarAprMayJunJulAugSepOctNovDec201913.0% of 154 movements17.4% of 138 movements15.2% of 151 movements33.5% of 155 movements30.6% of 144 movements40.4% of 136 movements31.2% of 138 movements30.9% of 136 movements25.0% of 136 movements25.5% of 161 movements9.0% of 144 movements13.6% of 140 movements202029.7% of 148 movements32.4% of 139 movements27.5% of 109 movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movements2021suppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementssuppressed: fewer than twenty movementsno events in 29 movements †7.1% of 42 movements †2.0% of 49 movements †3.9% of 77 movements11.7% of 77 movements6.2% of 64 movements13.8% of 58 movements202212.7% of 55 movements15.5% of 58 movements19.0% of 79 movements8.7% of 126 movements19.3% of 119 movements38.2% of 131 movements40.1% of 142 movements33.6% of 137 movements25.0% of 128 movements21.5% of 144 movements14.4% of 132 movements37.6% of 125 movements202323.9% of 134 movements23.7% of 131 movements13.6% of 140 movements20.3% of 143 movements20.1% of 134 movements43.9% of 132 movements31.2% of 138 movements23.4% of 137 movements29.5% of 139 movements24.2% of 157 movements7.9% of 151 movements27.1% of 140 movements202411.5% of 131 movements13.3% of 128 movements6.8% of 133 movements12.0% of 142 movements19.7% of 137 movements13.4% of 134 movements24.6% of 138 movements21.5% of 135 movements17.4% of 138 movements21.8% of 156 movements14.0% of 150 movements37.8% of 143 movements202528.9% of 149 movements22.0% of 132 movements12.6% of 151 movements7.2% of 152 movements20.2% of 163 movements7.8% of 154 movements17.4% of 161 movements18.1% of 160 movements11.8% of 153 movements17.2% of 174 movements9.0% of 167 movements18.8% of 160 movements202612.3% of 163 movements7.2% of 152 movements20.5% of 171 movements18.3% of 164 movements10.7% of 169 movements13.9% of 166 movementsno datano datano datano datano datano data
Month-by-month table: median, observed range and sample
MonthMedianObserved rangeSample
Jan13.0%11.5–41.0%7 months, 925 flights
Feb17.4%7.2–29.0%7 months, 870 flights
Mar15.2%6.8–27.8%7 months, 983 flights
Apr18.3%7.2–33.5%7 months, 1,035 flights
May20.1%10.7–34.8%7 months, 1,007 flights
Jun38.2%7.8–65.2%7 months, 994 flights
Jul31.2%17.4–55.5%6 months, 863 flights
Aug27.1%18.1–41.5%6 months, 852 flights
Sep24.8%11.8–29.5%6 months, 852 flights
Oct23.0%17.2–28.0%6 months, 956 flights
Nov11.5%7.9–30.5%6 months, 898 flights
Dec25.4%13.6–37.8%6 months, 856 flights
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Which routes have the best and worst record?

Lowest disruption: LHR ↔ KEFLAVIK, 12.3% of 724 movements. Highest disruption: GLA ↔ KEFLAVIK, 18.2% of 351 movements.

The airline table uses this carrier on each route; airport and country tables combine carriers. Each figure is arrivals into its UK airport. Only sufficiently large exact samples enter the ordered comparison.

Observed disruption share by optionLhr ↔ Keflavik12.3% of 724 flightsMan ↔ Keflavik13.3% of 300 flightsEdi ↔ Keflavik15.6% of 147 flightsLgw ↔ Keflavik16.1% of 434 flightsGla ↔ Keflavik18.2% of 351 flights
All route comparisons and sample flags
RouteDisruptionCancellationsSample flag
Heathrow ↔ Keflavik12.3% of 724 movements1.1% of 724 movementsdescriptive comparison
Manchester ↔ Keflavik13.3% of 300 movements1.0% of 300 movementsdescriptive comparison
EDI ↔ KEFLAVIK15.6% of 147 movements2.0% of 147 movementsdescriptive comparison
Gatwick ↔ Keflavik16.1% of 434 movements2.3% of 434 movementsdescriptive comparison
GLA ↔ KEFLAVIK18.2% of 351 movements1.4% of 351 movementsdescriptive comparison
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Which UK airports appear in this record?

5 published groups have enough arrivals to describe.

These operations are not matched for season, aircraft or time of day. The table makes no causal comparison.

UK airportDisruptionSample flag
Edinburgh15.5% of 148 movementsdescriptive comparison
Glasgow18.2% of 351 movementsdescriptive comparison
Gatwick16.1% of 434 movementsdescriptive comparison
Heathrow12.4% of 725 movementsdescriptive comparison
Manchester13.3% of 300 movementsdescriptive comparison
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Arrivals vs departures

14.6% of 1,960 movements arrivals were disrupted, against 21.4% of 1,966 movements departures.

The directions have separate denominators. A departure delay does not establish late arrival at the final destination; legal conditions differ by direction and carrier.

Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Movements past the three-hour mark

0.6% of 1,960 movements were more than three hours late over July 2025 to June 2026.

Cancellation is counted separately and is not a three-hour delay. Monthly counts cannot establish a passenger claim.

Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Facts about this record

Icelandair appears from Jan 2018 to Jun 2026 with 12,026 arrivals.

The bounds describe the published record, not every commercial service. Final point is not necessarily a nonstop destination.

Archive route pairs: 44.

Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

What this data cannot tell you

Delay cause, individual passenger experience, commercial decisions and future performance are not established here.

Also absent are aircraft type, within-month time-of-day splits and cancellations made ahead of the short-notice reporting window.

0 operations (0.00%) excluded because their published percentages could not be reconciled to whole numbers. Excluded operations enter neither the numerator nor the denominator. Outcome figures and comparisons are unavailable when the excluded share exceeds fifteen percent.

Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Quick answers

These answers use the same populations and window as the tables above.

Every percentage retains its denominator.

How disrupted are these arrivals?

14.6% of 1,960 movements over July 2025 to June 2026.

How often are they cancelled?

1.5% of 1,960 movements at short notice.

How late is late?

19.5–65.7 minutes; delayed denominator 258–769

Are services improving?

The monthly line records past changes; it is not a forecast or a causal comparison.

Which routes are compared?

The route table uses separately identified UK airport and final-point pairs, with small samples flagged.

Does this cover my flight?

Only published aggregate movements; the circumstances of any individual flight are unknown.

Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

How this was calculated

Source: CAA punctuality statistics · snapshot 17/08/2026 10:24 · method route-record-v2.1 · Versioned claims, formulas and entity mapping.

Integer bucket counts are recovered from rounding intervals over D=M+C+U with their sum constrained to M. Ambiguous counts remain ranges; failed reconciliation is quarantined.

Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.

Your trip has already gone wrong

The monthly line and events table show whether your month was typical or unusual in the published record.

Nothing here decides an individual case or what a passenger may be owed.

CAA: the official route to complain
Definitions, denominators and limits

Arrivals into UK reporting airports only unless labelled departures. Denominator: operated movements plus short-notice cancellations (M+C). A movement is not a scheduled flight. Unmatched records are data quality, not outcomes. Cells below twenty movements are suppressed; twenty to forty-nine are descriptive and not ranked.