London Heathrow – Shannon: how often flights are 3+ hours late or cancelled
Of 2,083 scheduled flights between London Heathrow and Shannon in 2025, 1.5% (95% range 1.0%–2.1%) were cancelled (25) or at least 3 hours late (about 6) — roughly 1 in 67. That is worse than 65% of 834 busy UK routes (median 1.1%). The route is 594 km, so when the airline is at fault UK261 compensation is £220 per passenger. This is an upper estimate: weather and air traffic control problems give no right to compensation. Source: UK CAA.
1.5%3+ hours late or cancelled
1 in 67flights
£220UK261 per passenger if the airline is at fault
The route in 2025
| Scheduled flights (both directions) | 2,083 |
|---|---|
| Cancelled | 25 |
| Operated but 3 hours or more late | about 6 |
| On time or within 15 minutes | 73% of operated flights |
| Average delay of operated flights | 13 minutes |
| Distance | 594 km (great circle, LHR–SNN) |
By direction
| Direction | Scheduled flights | 3h+ late or cancelled | 95% range |
|---|---|---|---|
| From London Heathrow | 1,039 | 1.2% | 0.7%–2.1% |
| To London Heathrow | 1,044 | 1.7% | 1.1%–2.7% |
Operated by Aer Lingus (2,078 scheduled flights).
What you may be owed
| Distance | Delay at arrival | UK261 compensation |
|---|---|---|
| 594 km | 3 hours or more, or a cancellation less than 14 days ahead | £220 per passenger |
Weather is a frequent reason why no compensation is due: at London Heathrow EUROCONTROL restricted arrivals for weather on 32% of days in 2018–2026.
Caveats
- This is an upper estimate of flights where compensation may be due. Weather, air traffic control, strikes by third parties and security problems are “extraordinary circumstances” and give no right to compensation; cancellations announced 14 days or more ahead do not either.
- The CAA measures delay at the UK airport (departure or arrival). The legal test is the delay on arrival at the final destination.
- Flights in both directions are combined. For flights from an EU airport, EU261 applies when the airline is an EU airline (€250 / €400 / €600), UK261 when it is a UK airline.
CAA destination name: Shannon.