UK FLIGHT DELAY INDEX

derived from CAA punctuality statistics for UK reporting airports

How often are these flights late or cancelled?

KLM Cityhopper

In the twelve months from July 2025 to June 2026, 20.0% of 3,073 movements arriving into the UK were disrupted — more than fifteen minutes late or cancelled at short notice.

Put the other way round, 80.0% of 3,073 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

20.0% of 3,073 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
20.0% of 3,073 movements0.5% of 3,073 movements16.2–53.5 minutes; delayed denominator 602–1,8030.0% of 3,073 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?

0.0% of 3,073 movements passed the three-hour mark.

The ladder shows how many movements crossed each threshold. Cancellations are separate: 0.5% of 3,073 movements.

DelayShare and sampleOne event per movements
More than 15 minutes19.6% of 3,073 movements5.1
More than 30 minutes9.1% of 3,073 movements11.0
More than 60 minutes3.4% of 3,073 movements29.8
More than 120 minutes0.4% of 3,073 movements236.4
More than 180 minutes0.0% of 3,073 movements3,073.0
More than 360 minutesno events in 3,073 movementsNo observed events; this is not zero risk.
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?

0.4% of 3,073 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 early652.1%15–1 early1,19138.8%0–15 late1,20139.1%16–3032210.5%31–601775.8%61…120902.9%121…180120.4%181…36010.0%>36000.0%D=3,073
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: May 2021, no events in 104 movements. Worst month: Sep 2022, 42.1% of 140 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: 9.8%; sample: 1122018Feb 2018: 12.6%; sample: 103Mar 2018: 10.4%; sample: 154Apr 2018: 8.8%; sample: 125May 2018: 11.5%; sample: 130Jun 2018: 12.4%; sample: 121Jul 2018: 14.5%; sample: 145Aug 2018: 4.5%; sample: 133Sep 2018: 16.4%; sample: 189Oct 2018: 9.9%; sample: 162Nov 2018: 5.5%; sample: 128Dec 2018: 8.3%; sample: 120Jan 2019: 4.7%; sample: 1072019Feb 2019: 10.9%; sample: 110Mar 2019: 17.4%; sample: 132Apr 2019: 6.7%; sample: 60May 2019: 15.3%; sample: 85Jun 2019: 11.1%; sample: 90Jul 2019: 14.4%; sample: 97Aug 2019: 6.2%; sample: 97Sep 2019: 30.2%; sample: 96Oct 2019: 20.8%; sample: 106Nov 2019: 5.1%; sample: 118Dec 2019: 9.6%; sample: 114Jan 2020: 11.4%; sample: 352020Feb 2020: 13.2%; sample: 91Mar 2020: suppressed: fewer than twenty movements×Apr 2020: 2.1%; sample: 47May 2020: 3.2%; sample: 31Jun 2020: 5.0%; sample: 60Jul 2020: suppressed: fewer than twenty movements×Aug 2020: 3.4%; sample: 175Sep 2020: 2.1%; sample: 193Oct 2020: 1.0%; sample: 201Nov 2020: 1.7%; sample: 121Dec 2020: 5.6%; sample: 90Jan 2021: 9.8%; sample: 822021Feb 2021: suppressed: fewer than twenty movements×Mar 2021: 18.2%; sample: 22Apr 2021: 6.2%; sample: 80May 2021: 0.0%; sample: 104Jun 2021: 7.5%; sample: 120Jul 2021: 6.0%; sample: 182Aug 2021: 19.5%; sample: 169Sep 2021: 13.3%; sample: 165Oct 2021: 18.0%; sample: 178Nov 2021: 12.8%; sample: 164Dec 2021: 15.0%; sample: 160Jan 2022: 17.3%; sample: 1042022Feb 2022: 21.6%; sample: 88Mar 2022: 12.9%; sample: 140Apr 2022: 40.5%; sample: 163May 2022: 41.7%; sample: 163Jun 2022: 35.6%; sample: 160Jul 2022: 34.0%; sample: 191Aug 2022: 19.0%; sample: 189Sep 2022: 42.1%; sample: 140Oct 2022: 23.2%; sample: 142Nov 2022: 8.8%; sample: 159Dec 2022: 23.3%; sample: 159Jan 2023: 9.0%; sample: 1662023Feb 2023: 4.8%; sample: 165Mar 2023: 18.8%; sample: 208Apr 2023: 12.6%; sample: 198May 2023: 17.4%; sample: 195Jun 2023: 22.0%; sample: 200Jul 2023: 20.6%; sample: 165Aug 2023: 20.4%; sample: 191Sep 2023: 20.6%; sample: 262Oct 2023: 26.8%; sample: 257Nov 2023: 24.7%; sample: 182Dec 2023: 30.5%; sample: 177Jan 2024: 23.8%; sample: 2102024Feb 2024: 19.4%; sample: 201Mar 2024: 16.1%; sample: 193Apr 2024: 27.6%; sample: 286May 2024: 18.4%; sample: 299Jun 2024: 21.4%; sample: 285Jul 2024: 20.6%; sample: 218Aug 2024: 15.0%; sample: 240Sep 2024: 27.4%; sample: 270Oct 2024: 24.7%; sample: 251Nov 2024: 26.2%; sample: 214Dec 2024: 24.2%; sample: 215Jan 2025: 33.7%; sample: 1752025Feb 2025: 22.0%; sample: 182Mar 2025: 26.4%; sample: 227Apr 2025: 11.8%; sample: 220May 2025: 17.1%; sample: 258Jun 2025: 18.8%; sample: 256Jul 2025: 32.0%; sample: 278Aug 2025: 25.8%; sample: 283Sep 2025: 31.2%; sample: 247Oct 2025: 26.6%; sample: 256Nov 2025: 13.4%; sample: 247Dec 2025: 12.9%; sample: 249Jan 2026: 29.3%; sample: 1882026Feb 2026: 10.6%; sample: 198Mar 2026: 13.7%; sample: 262Apr 2026: 11.5%; sample: 286May 2026: 15.0%; sample: 294Jun 2026: 19.3%; sample: 285Pandemic regime Jun 2020Summer 2022 breakdown Jul 2022NATS system failure Aug 2023Heathrow fire closure Mar 2025100%0%
Every monthly observation
MonthDisruption on arrivals
Jan 20189.8% of 112 movements
Feb 201812.6% of 103 movements
Mar 201810.4% of 154 movements
Apr 20188.8% of 125 movements
May 201811.5% of 130 movements
Jun 201812.4% of 121 movements
Jul 201814.5% of 145 movements
Aug 20184.5% of 133 movements
Sep 201816.4% of 189 movements
Oct 20189.9% of 162 movements
Nov 20185.5% of 128 movements
Dec 20188.3% of 120 movements
Jan 20194.7% of 107 movements
Feb 201910.9% of 110 movements
Mar 201917.4% of 132 movements
Apr 20196.7% of 60 movements
May 201915.3% of 85 movements
Jun 201911.1% of 90 movements
Jul 201914.4% of 97 movements
Aug 20196.2% of 97 movements
Sep 201930.2% of 96 movements
Oct 201920.8% of 106 movements
Nov 20195.1% of 118 movements
Dec 20199.6% of 114 movements
Jan 202011.4% of 35 movements — small sample, not ranked
Feb 202013.2% of 91 movements
Mar 2020suppressed: fewer than twenty movements
Apr 20202.1% of 47 movements — small sample, not ranked
May 20203.2% of 31 movements — small sample, not ranked
Jun 20205.0% of 60 movements
Jul 2020suppressed: fewer than twenty movements
Aug 20203.4% of 175 movements
Sep 20202.1% of 193 movements
Oct 20201.0% of 201 movements
Nov 20201.7% of 121 movements
Dec 20205.6% of 90 movements
Jan 20219.8% of 82 movements
Feb 2021suppressed: fewer than twenty movements
Mar 202118.2% of 22 movements — small sample, not ranked
Apr 20216.2% of 80 movements
May 2021no events in 104 movements
Jun 20217.5% of 120 movements
Jul 20216.0% of 182 movements
Aug 202119.5% of 169 movements
Sep 202113.3% of 165 movements
Oct 202118.0% of 178 movements
Nov 202112.8% of 164 movements
Dec 202115.0% of 160 movements
Jan 202217.3% of 104 movements
Feb 202221.6% of 88 movements
Mar 202212.9% of 140 movements
Apr 202240.5% of 163 movements
May 202241.7% of 163 movements
Jun 202235.6% of 160 movements
Jul 202234.0% of 191 movements
Aug 202219.0% of 189 movements
Sep 202242.1% of 140 movements
Oct 202223.2% of 142 movements
Nov 20228.8% of 159 movements
Dec 202223.3% of 159 movements
Jan 20239.0% of 166 movements
Feb 20234.8% of 165 movements
Mar 202318.8% of 208 movements
Apr 202312.6% of 198 movements
May 202317.4% of 195 movements
Jun 202322.0% of 200 movements
Jul 202320.6% of 165 movements
Aug 202320.4% of 191 movements
Sep 202320.6% of 262 movements
Oct 202326.8% of 257 movements
Nov 202324.7% of 182 movements
Dec 202330.5% of 177 movements
Jan 202423.8% of 210 movements
Feb 202419.4% of 201 movements
Mar 202416.1% of 193 movements
Apr 202427.6% of 286 movements
May 202418.4% of 299 movements
Jun 202421.4% of 285 movements
Jul 202420.6% of 218 movements
Aug 202415.0% of 240 movements
Sep 202427.4% of 270 movements
Oct 202424.7% of 251 movements
Nov 202426.2% of 214 movements
Dec 202424.2% of 215 movements
Jan 202533.7% of 175 movements
Feb 202522.0% of 182 movements
Mar 202526.4% of 227 movements
Apr 202511.8% of 220 movements
May 202517.1% of 258 movements
Jun 202518.8% of 256 movements
Jul 202532.0% of 278 movements
Aug 202525.8% of 283 movements
Sep 202531.2% of 247 movements
Oct 202526.6% of 256 movements
Nov 202513.4% of 247 movements
Dec 202512.9% of 249 movements
Jan 202629.3% of 188 movements
Feb 202610.6% of 198 movements
Mar 202613.7% of 262 movements
Apr 202611.5% of 286 movements
May 202615.0% of 294 movements
Jun 202619.3% of 285 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 2020Arrivals5.0% of 60 movementsno complete baselinenot enough data: needs a complete baseline and a publishable event month
Pandemic regime · Jun 2020Departures8.3% of 60 movementsno complete baselinenot enough data: needs a complete baseline and a publishable event month
Summer 2022 breakdown · Jul 2022Arrivals34.0% of 191 movements21.2% across 1,836 flightsreturned the next month
Summer 2022 breakdown · Jul 2022Departures40.7% of 189 movements27.0% across 1,822 flightsreturned the next month
NATS system failure · Aug 2023Arrivals20.4% of 191 movements18.5% across 2,086 flightsreturned after 7 months
NATS system failure · Aug 2023Departures28.0% of 189 movements26.6% across 2,089 flightsreturned the next month
Heathrow fire closure · Mar 2025Arrivals26.4% of 227 movements23.1% across 2,828 flightsreturned the next month
Heathrow fire closure · Mar 2025Departures29.4% of 228 movements30.9% across 2,804 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: Sep, 28.8% across 6 months. Lowest median: Nov, 11.1% 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 nJanFebMarAprMayJunJulAugSepOctNovDec20194.7% of 107 movements10.9% of 110 movements17.4% of 132 movements6.7% of 60 movements15.3% of 85 movements11.1% of 90 movements14.4% of 97 movements6.2% of 97 movements30.2% of 96 movements20.8% of 106 movements5.1% of 118 movements9.6% of 114 movements202011.4% of 35 movements †13.2% of 91 movementssuppressed: fewer than twenty movements2.1% of 47 movements †3.2% of 31 movements †5.0% of 60 movementssuppressed: fewer than twenty movements3.4% of 175 movements2.1% of 193 movements1.0% of 201 movements1.7% of 121 movements5.6% of 90 movements20219.8% of 82 movementssuppressed: fewer than twenty movements18.2% of 22 movements †6.2% of 80 movementsno events in 104 movements7.5% of 120 movements6.0% of 182 movements19.5% of 169 movements13.3% of 165 movements18.0% of 178 movements12.8% of 164 movements15.0% of 160 movements202217.3% of 104 movements21.6% of 88 movements12.9% of 140 movements40.5% of 163 movements41.7% of 163 movements35.6% of 160 movements34.0% of 191 movements19.0% of 189 movements42.1% of 140 movements23.2% of 142 movements8.8% of 159 movements23.3% of 159 movements20239.0% of 166 movements4.8% of 165 movements18.8% of 208 movements12.6% of 198 movements17.4% of 195 movements22.0% of 200 movements20.6% of 165 movements20.4% of 191 movements20.6% of 262 movements26.8% of 257 movements24.7% of 182 movements30.5% of 177 movements202423.8% of 210 movements19.4% of 201 movements16.1% of 193 movements27.6% of 286 movements18.4% of 299 movements21.4% of 285 movements20.6% of 218 movements15.0% of 240 movements27.4% of 270 movements24.7% of 251 movements26.2% of 214 movements24.2% of 215 movements202533.7% of 175 movements22.0% of 182 movements26.4% of 227 movements11.8% of 220 movements17.1% of 258 movements18.8% of 256 movements32.0% of 278 movements25.8% of 283 movements31.2% of 247 movements26.6% of 256 movements13.4% of 247 movements12.9% of 249 movements202629.3% of 188 movements10.6% of 198 movements13.7% of 262 movements11.5% of 286 movements15.0% of 294 movements19.3% of 285 movementsno datano datano datano datano datano data
Month-by-month table: median, observed range and sample
MonthMedianObserved rangeSample
Jan17.3%4.7–33.7%7 months, 1,062 flights
Feb12.6%4.8–22.0%7 months, 1,047 flights
Mar16.1%10.4–26.4%7 months, 1,316 flights
Apr11.8%6.7–40.5%7 months, 1,338 flights
May17.1%11.5–41.7%7 months, 1,424 flights
Jun19.3%11.1–35.6%7 months, 1,397 flights
Jul20.6%14.4–34.0%6 months, 1,094 flights
Aug17.0%4.5–25.8%6 months, 1,133 flights
Sep28.8%16.4–42.1%6 months, 1,204 flights
Oct24.0%9.9–26.8%6 months, 1,174 flights
Nov11.1%5.1–26.2%6 months, 1,048 flights
Dec18.1%8.3–30.5%6 months, 1,034 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: BHD ↔ AMS, 18.9% of 661 movements. Highest disruption: SOU ↔ AMS, 20.7% of 686 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 optionBhd ↔ Ams18.9% of 661 flightsAbz ↔ Ams20.2% of 1,347 flightsGla ↔ Ams20.3% of 374 flightsSou ↔ Ams20.7% of 686 flights
All route comparisons and sample flags
RouteDisruptionCancellationsSample flag
Belfast City (George Best) ↔ Amsterdam18.9% of 661 movements2.1% of 661 movementsdescriptive comparison
Aberdeen ↔ Amsterdam20.2% of 1,347 movementsno events in 1,347 movementsdescriptive comparison
Glasgow ↔ Amsterdam20.3% of 374 movementsno events in 374 movementsdescriptive comparison
Southampton ↔ Amsterdam20.7% of 686 movementsno events in 686 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?

4 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
Aberdeen20.2% of 1,347 movementsdescriptive comparison
Belfast City (George Best)19.0% of 662 movementsdescriptive comparison
Glasgow20.3% of 374 movementsdescriptive comparison
Southampton20.7% of 686 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

20.0% of 3,073 movements arrivals were disrupted, against 25.9% of 3,057 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

0.0% of 3,073 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

KLM Cityhopper appears from Jan 2018 to Jun 2026 with 16,748 arrivals.

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

Archive route pairs: 17.

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?

20.0% of 3,073 movements over July 2025 to June 2026.

How often are they cancelled?

0.5% of 3,073 movements at short notice.

How late is late?

16.2–53.5 minutes; delayed denominator 602–1,803

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.