Check your travel day
Data available from 1 January 2024 to 30 September 2026 for 233 airports. Not on the list? The airport is not covered by EUROCONTROL’s airport data (smaller and non-European airports).
What the data shows
When an airport or the airspace around it cannot safely handle all the planned traffic, the Network Manager at EUROCONTROL issues a flow regulation: aircraft heading there get a later take-off slot and wait on the ground at their departure airport. Each regulation carries a reason code – weather, air traffic control capacity or staffing, strikes, runway works and so on. EUROCONTROL adds up, per airport and per day, the minutes of delay these regulations caused to arriving flights and how many flights were affected.
That is exactly the kind of event airlines rely on when they reject a claim (“adverse weather”, “ATC restrictions”). The data lets you see whether such restrictions existed at your airports that day, how severe they were compared with a normal day, and what they were attributed to.
Using the result in a claim
- No restrictions recorded: if the airline blamed weather or ATC and neither airport shows any regulation for that reason, quote the result in your reply and ask the airline to identify the specific event and the evidence for it. The burden of proof is on the airline.
- Small restrictions: an average of a few minutes per delayed flight rarely explains a delay of three hours or more. Ask how a short restriction caused your long delay.
- Major restrictions: the airline’s explanation is plausible. It still has to show the restriction caused your delay and that it took all reasonable measures – see bad weather and air traffic control.
- Strikes: an air traffic controllers’ strike is generally extraordinary; a strike by the airline’s own staff is not (strikes and compensation).
Our complaint letter generator and ADR complaint template help you put this in writing.
Cause codes explained
| Code | Reason | What it means for you |
|---|---|---|
| W | Weather | Low visibility, thunderstorms, strong winds, snow or ice affecting the airport. The classic “extraordinary circumstance” – but only if it actually caused your delay. |
| D | De-icing | Queues for aircraft de-icing in winter. Weather-related; whether the airline prepared reasonably matters. |
| C | ATC capacity | Air traffic control could not handle the demand. Outside the airline’s control. |
| S | ATC staffing | Not enough controllers on duty. Outside the airline’s control. |
| I | Industrial action (ATC) | Air traffic controllers on strike. Generally extraordinary. |
| N | Industrial action (non-ATC) | Strikes by others – for example airport staff. Not the airline’s own staff, which the CJEU says is not extraordinary. |
| G | Aerodrome capacity | The airport could not take more arrivals – runway works, runway closures, stand or gate limits. |
| E | Equipment (non-ATC) | Airport equipment failure, e.g. runway lighting or landing aids not run by ATC. |
| T | Equipment (ATC) | Failure of air traffic control equipment (radar, radio, flight data systems). |
| R | ATC routeing | Restrictions on the route structure, often linked to airspace closures. |
| M | Airspace management | Military areas or airspace closures limiting civil traffic. |
| V | Environmental issues | Noise restrictions and other environmental rules. |
| P | Special event | Major events (summits, sports finals, air shows). |
| A | Accident/incident | An accident or incident at or near the airport. |
| O | Other | Anything else. |
Limits of the data
- It records arrival flow regulations per airport. En-route restrictions (for example an ATC strike in another country that your flight crossed) are not attributed to your airports.
- It does not show the airline’s own problems – technical faults, crew shortages, a late inbound aircraft – which cause most long delays.
- An aircraft can be delayed by weather earlier in its day at an airport that is not on your ticket. Ask the airline which flight and airport were affected.
- Delay minutes are totals for all arriving flights; your flight may have been affected more or less than average.
Frequently asked questions
My airline says the delay was caused by bad weather. Do I have to accept that?
No. Under both EU261 and UK261 the airline has to prove that an extraordinary circumstance caused the delay and that it could not have been avoided even with all reasonable measures. A one-line “adverse weather” rejection is not proof. Ask which airport, which time and which flight was affected, and compare it with what EUROCONTROL recorded.
The tool shows no weather restrictions on my day. Does that mean I win?
Not automatically. Weather can affect a flight without leading to an air traffic flow regulation at your arrival airport – for example a storm at an airport earlier in the aircraft’s day, or en-route restrictions. But if neither your departure nor your arrival airport had any weather-related regulation, it is a strong reason to ask the airline for evidence and, if it has none, to escalate to ADR or the CAA.
Heavy weather regulation is shown. Is my claim lost?
Not necessarily. The weather must have caused your delay of 3 hours or more. An average ATFM delay of 20 minutes per delayed flight does not explain a 4-hour delay on its own, and knock-on delays from an earlier day are not covered. If the airline’s explanation does not add up, ask for the details.
Where does the data come from?
From EUROCONTROL’s open performance data: the daily arrival air traffic flow management (ATFM) delay for each airport, broken down by the reason code the flow management unit gives each regulation. It covers 233 airports in our database from 1 January 2024 to 30 September 2026. EUROCONTROL publishes new months with a delay of a few weeks; we update the tool when it does.
Is my departure airport’s data relevant if it lists arrival delays?
Yes, as an indicator. Weather, staffing shortages or runway problems that restrict arrivals at an airport usually affect the whole airport that day. The data is recorded for arrivals, so it is most direct for your arrival airport; for the departure airport it shows whether conditions there were disrupted.
Source: EUROCONTROL (Aviation Intelligence Portal, airport arrival ATFM delay), processed by EU261 Flight Delay. Information only, not legal advice.
Sources
- EUROCONTROL – airport arrival ATFM delays (open performance data) – EUROCONTROL
- C-549/07 Wallentin-Hermann v Alitalia (extraordinary circumstances) – Court of Justice of the EU
- C-28/20 Airhelp v SAS (airline staff strike is not extraordinary) – Court of Justice of the EU
- Delays – extraordinary circumstances – UK Civil Aviation Authority
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