Methodology and sources

How often weather restricts arrivals at Europe's airports, month by month (EUROCONTROL 2018–2026, with the weather reported at the airport), and how often UK flights are 3+ hours late or cancelled on each route, with the UK261 compensation amount (CAA 2025).

Weather restrictions at European airports

• Data: EUROCONTROL's daily airport arrival delays from air traffic flow management (ATFM) regulations, by reason, January 2018 – September 2026 (293 airports). When the network manager expects more arrivals than an airport can take — in fog, low cloud, thunderstorms, strong wind, snow — it issues a regulation, and flights wait at their departure airport. We count a weather restriction day when any arrival delay minutes carry reason W (weather).
• An airport gets a page from 10 such days and is listed and indexed from 30 (about 70 airports). Many airports almost never regulate for weather — not because the weather is always good, but because they handle it differently (for example Madeira: diversions and cancellations are not regulations).
• What it does not cover: departures, delays not caused by regulations, cancellations and diversions.
• Weather on those days: the airport's own METAR reports (Iowa Environmental Mesonet archive), 05–21 UTC. A day counts as “thunderstorm” with at least one report of TS; “fog” with at least two reports of visibility under 800 m or fog; “low cloud” with at least two reports of a broken or overcast base at 200 ft or lower; gusts of 30 knots or more; crosswind of 20 knots or more (sustained wind) on the best-aligned runway (OurAirports headings); snow; freezing rain or drizzle. Days with fewer than 20 reports are left out. In our check of 26 airports in 2026, the day's weather explained only part of the restriction days; we show it as what came with the delays, not as their cause.

UK flights 3+ hours late or cancelled

• Data: UK Civil Aviation Authority punctuality statistics for 2025 (annual, by arrival and departure), scheduled flights only, at the 25 UK airports the CAA reports.
• Share = (cancelled + operated flights 3 hours or more late) ÷ (operated + cancelled). The CAA gives the share of operated flights in delay bands (181–360 and over 360 minutes); multiplied by the number of operated flights this gives “about” a number of late flights. The 95% range is the Wilson interval.
• Route = UK airport × destination airport, both directions. CAA destination names (“OPORTO”, “TENERIFE (SURREINA SOFIA)”) are matched to airports with a dictionary built and checked by hand (99% of flights; checked independently on a random sample). Domestic routes are reported by both UK airports; we show one page per pair, with the figures of the busier airport. Pages exist for routes with at least 500 scheduled flights.
• Airlines are shown as the operating companies listed by the CAA. On a route, an airline is shown from 100 scheduled flights, and we say whether the 95% ranges overlap — usually they do, so the difference is not meaningful.
• Airline at a UK airport: pages exist for airlines with a hub page (2,000+ scheduled UK flights) at each UK airport where they had at least 500 scheduled flights in 2025; they are offered to search engines from 1,000 flights and two destinations, and only where the airport has less than 90% of the airline's UK flights (otherwise the route or airline page says the same). “Other airlines at the airport” is all scheduled flights there minus the airline; we say whether the two 95% ranges overlap. Destinations are listed from 100 scheduled flights.
• UK261 amounts by great-circle distance (OurAirports coordinates): £220 up to 1,500 km, £350 to 3,500 km, £520 beyond. This is not legal advice: compensation depends on the cause, on when a cancellation was announced and on the airline.

Licences

• EUROCONTROL data: “Source: EUROCONTROL”. We publish no downloads derived from it.
• CAA data: Open Government Licence v3.0.

Sources and licences