- May is the best month to fly, with only 31% of flights delayed compared to July and September last year at 44%
- Flights departing at 5 a.m. experience the least delays at 15%, compared to those between 2 p.m. – 8 p.m. at over 50%
- Nottingham, Liverpool, Cardiff had the fewest flight delays compared to London airports
There’s nothing worse than starting your summer trip with a delayed or cancelled flight, so Rachel Mumford, Travel Expert at KAYAK, the world’s leading travel search engine, is sharing her essential tips on key timings, travel dates and airport choices to help Brits with a smoother journey.
THE BEST AND THE WORST MONTHS TO FLY THIS SUMMER
Summer months typically see the highest volume of travellers, with school holidays starting, the festival season ramping up, and an increased demand for a hot summer trip away.
To help travellers navigate this busy time and avoid flight delays, Rachel says: “If you’re looking to reach your holiday destination on time, May is an attractive month to fly with only 31% of flights delayed compared to July and September last year at 44% – which were the busiest months of the year for delays.
“However, with kids starting their school summer holidays, it’s likely that July will be a popular option. For those who are flying out this month, where possible, try and avoid flying on the 17th and 29th, when tickets were most expensive last year.
“August 1st is also expected to be the busiest day for flying, so choosing an alternative date would help avoid crowds. If you’re unsure about dates, use KAYAK’s ‘Best Time to Travel’ tool to know when you should travel and when to book for a great price.”
THE BEST AND WORST TIMES TO FLY
Brits who don’t mind sacrificing their sleep have better chances of a timely departure as the earlier the flight, the lower the chances are of delays. Last year, only 15% of flights departing at 5 a.m. were delayed, compared to over half (51%) of the flights departing between 2 p.m. and 8 p.m.
Rachel says: “Flying before 7 a.m. is ideal, however, if that doesn’t match your schedule, then try and avoid flying in the afternoon and evening. Plus, for those taking international flights, choosing an earlier flight at 5 a.m. is cheaper than late night flights between 9 p.m. – 10 p.m.”
| Flight Departure Time | % of flight delays | |||
|---|---|---|---|---|
| 5:00 | 15% | |||
| 6:00 | 20% | |||
| 7:00 | 26% | |||
| 8:00 | 31% | |||
| 9:00 | 38% | |||
| 10:00 | 39% | |||
| 11:00 | 42% | |||
| 12:00 | 46% | |||
| 13:00 | 47% | |||
| 14:00 | 51% | |||
| 15:00 | 50% | |||
| 16:00 | 53% | |||
| 17:00 | 52% | |||
| 18:00 | 51% | |||
| 19:00 | 50% | |||
| 20:00 | 50% | |||
| 21:00 | 46% | |||
| 22:00 | 41% | |||
| 23:00 | 35% |
THE BEST AND THE WORST UK AIRPORTS TO FLY FROM
Smaller airports may offer fewer shopping and dining options but provide some of the best chances of on-time departures and the fewest cancellations.
Rachel says: “Nottingham, Liverpool and Bournemouth were some of the most punctual airports in the UK last year compared to London City, London Heathrow, London Gatwick and Belfast. However, not all smaller airports are exempt, as Aberdeen Airport had the most cancellations by far, at 3.1%.
“For travellers who have no choice but to travel through bigger and busier airports, they should allow ample layover time for delays. For intercontinental flights, try and go through smaller airports or fly direct to avoid layovers.”
LIST OF TOP 20 UK AIRPORTS WITH LEAST DELAYS IN 2024
Please note the below is listed with the smallest percentage of flights delayed.
| AIRPORT | CITY | AVERAGE DELAY | % OF FLIGHTS DELAYED | % OF CANCELLATION | ||||
|---|---|---|---|---|---|---|---|---|
| EMA | Nottingham | 19 min | 15% | 0.2% | ||||
| LPL | Liverpool | 19 min | 16% | 0.6% | ||||
| BHD | Belfast (George Best) | 17 min | 17% | 1.3% | ||||
| BOH | Bournemouth | 19 min | 18% | 0.1% | ||||
| CWL | Cardiff | 20 min | 18% | 0.3% | ||||
| NCL | Newcastle upon Tyne | 20 min | 18% | 0.5% | ||||
| LBA | Leeds | 21 min | 20% | 0.3% | ||||
| INV | Inverness | 22 min | 21% | 0.9% | ||||
| ABZ | Aberdeen | 24 min | 23% | 3.1% | ||||
| BFS | Belfast | 23 min | 24% | 0.6% | ||||
| LCY | London (City) | 23 min | 25% | 2.7% | ||||
| BRS | Bristol | 26 min | 32% | 0.5% | ||||
| GLA | Glasgow | 26 min | 32% | 0.9% | ||||
| EDI | Edinburgh | 29 min | 38% | 1.0% | ||||
| ABZ | Londin (Luton) | 32 min | 39% | 0.4% | ||||
| BHX | Birmingham | 31 min | 40% | 0.6% | ||||
| STN | London (Stansted) | 32 min | 43% | 0.2% | ||||
| MAN | Manchester | 32 min | 45% | 0.7% | ||||
| LHR | London (Heathrow) | 35 min | 49% | 1.6% | ||||
| LGW | London (Gatwick) | 37 min | 57% | 1.3% |
Notes
About KAYAK
KAYAK, part of Booking Holdings (NASDAQ: BKNG), is the world’s leading travel search engine. With billions of searches on our platforms, we help people find their perfect flight, accommodation, car rental and holiday package. We also support business travellers with our corporate travel solution.
KAYAK Data Methodology:
Airport selection
KAYAK considered the 20 most searched departure airports in the United Kingdom based on flight search data from KAYAK.co.uk between 1 January 2024 and 31 December 2024.
Selected airports are: London Gatwick (LGW), London Heathrow (LHR), Manchester (MAN), London Stansted (STN), Birmingham (BHX), London Luton (LTN), Edinburgh (EDI), Bristol (BRS), Glasgow (GLA), London City (LCY), Belfast International (BFS), Aberdeen (ABZ), Inverness (INV), Leeds Bradford (LBA), Bournemouth (BOH), Cardiff (CWL), Newcastle (NCL), George Best Belfast City (BHD), Liverpool John Lennon (LPL), and East Midlands (EMA).
Data on the most searched destinations by British travellers is based on flight search data between 1 Jan and 10 Feb 2025, for travel between 1 Jun – 1 Oct 2025. Airports in the Top 25 most searched destinations were analysed.
Aviation Edge
Aviation Edge is a comprehensive aviation database providing real-time information on flights, airports, and airlines. https://aviation-edge.com/ (Data was collected on January 28, 2025).
Full-year analysis: Covers flights between 1 January 2024 and 31 December 2024, to provide an annual overview.
Summer travel season analysis: Focuses on peak holiday months, covering 1 Jun – 15 Sep 2024, and 1 Jun – 15 Sep 15, 2023, for comparison.
For the 15 selected airports, data from Aviation Edge is used to calculate the percentage of flights delayed (departure delays) and cancelled for each date, hour and airport. Only flights designated for passenger travel are considered.
In this analysis, a flight is categorised as delayed if its departure is postponed by 30 minutes or more.
In Aviation Edge, flight delay is calculated based on the “wheels-off” approach. This means the delay is measured from the moment the aircraft takes off rather than when it departs from the gate.
Cirium
Cirium is a leading aviation analytics provider (https://www.cirium.com/).
The traffic growth data for the 15 German airports is coming from Cirium (Data was collected on 28 January 2025).
It covers travel periods Jun – Sep 2024 and Jun – Sep 2025, comparing total flight numbers year-over-year.
KAYAK-Data
The busiest and most expensive dates to depart were based on KAYAK flight data from searches between 1 January 2025 and 10 February 2025 for travel between 1 June 2025 and 1 October 2025.
