SNN to LHR flight delays
1,393 flights · March 2025 – August 2026 · UK Civil Aviation Authority
77.75%
Arrived on time
Within 15 minutes of schedule
0.93%
Cancelled
Share of scheduled flights
—
When late, late by
Average across delayed arrivals
10 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The season swings this route hard. In May it ran 32.1 points more punctual than in December — a difference bigger than the one between the best and worst airlines on most routes. If the date is flexible, it is worth more than the carrier.
Only Aer Lingus flies this route in the published record, so there is no choice to weigh — the route's figures and the airline's are the same figures.
The Shannon to London route sits close to the middle of the record — neither notably punctual nor notably late.
Which airline should you fly on this route?
Over March 2025 – August 2026, Aer Lingus arrived on time most often on SNN to LHR. Flights ran closest to schedule in May and worst in December.
Every airline on SNN to LHR
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Aer Lingus | 1,387 | 78.04% | 0.87% | — | C |
| Virgin Atlantic | 4 | 0% | 25% | — | — |
| British Airways | 2 | 0% | 0% | — | — |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
LHR to SNN London back to Shannon 73.28% on time CCommon questions
Are flights from Shannon to London usually delayed?
77.75% of flights on the SNN to LHR route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is about the same as the average route in this record.
Which airlines fly from Shannon to London?
Only Aer Lingus appears in the published record on this route, with 1,387 flights and 78.04% arriving on time.
How often are SNN to LHR flights cancelled?
0.93% of scheduled flights did not operate — about 9 in every thousand. That is in the normal range.
What is the best month to fly Shannon to London?
May, when 87.5% of flights arrived on time. The worst was December at 55.4%.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on SNN to LHR during March 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →