When are flights cheapest? The cheapest month on 28 routes
On 28 routes, the cheapest one-way fare of the next ten months was found most often for Dec 2026: 13 of 28 routes. The highest fares against a route's median were found for Jul 2027 (125%).
What this data can and cannot say
Each route has one fare per departure month: the cheapest one-way fare travellers found for a flight in that month. The data has no fare for every day and no price history, so it cannot say which day of the week is cheapest or how far ahead to book.
On 13 routes, the cheapest month is December. Those fares are for departures between 1 and 31 December, so they show where the lower fares were found in the weeks ahead, not what a holiday trip costs.
On 3 routes, two or more months share the lowest fare. The shorter journey decides which month counts as the cheapest, then the earlier month.
What we looked at
For each of 28 routes with a page (fares in at least six of the next ten months, kept while at least three months have a fare), the data gives the cheapest one-way fare that travellers found for each departure month. Routes differ too much to compare in money (a hop between two UK cities and a flight across the Atlantic, in pounds for UK origins and dollars for US ones), so each month's fare is set against the median of that route's own months: 100% is the route's usual fare, 75% is a quarter below it.
Month by month across 28 routes
| Departure month | Routes with a fare | Routes cheapest here | Routes priciest here | Fare against the route's median |
|---|---|---|---|---|
| Nov 2026 | 28 | 3 | 2 | 92% |
| Dec 2026 | 28 | 13 cheapest | 0 | 78% |
| Jan 2027 | 28 | 7 | 2 | 82% |
| Feb 2027 | 22 | 2 | 1 | 95% |
| Mar 2027 | 23 | 2 | 3 | 100% |
| Apr 2027 | 18 | 1 | 0 | 106% |
| May 2027 | 23 | 0 | 4 | 117% |
| Jun 2027 | 11 | 0 | 4 | 116% |
| Jul 2027 | 17 | 0 | 6 | 125% |
| Aug 2027 | 14 | 0 | 6 | 116% |
The last column is the median of the routes' monthly readings. The month with the lowest reading is Dec 2026 at 78%; the highest is Jul 2027 at 125%.
What the table says
The cheapest month of a route fell in Nov 2026, Dec 2026, Jan 2027, Feb 2027, Mar 2027 and Apr 2027, and nowhere else in the window. Dec 2026 was the cheapest month for 13 routes, the most of any month. Readings of 120% or more of the route's median appear for Jul 2027.
That is a statement about the fares found in these ten months. It points to where the lower fares were found, not to a rule that holds every year.
Read it with care
- The fares are the cheapest that travellers found in recent searches, not live quotes. A fare may have changed or sold out.
- Fewer routes have a fare for Jun 2027 and Aug 2027 (11, 14 of 28), because fewer travellers search that far ahead; those readings rest on fewer routes.
- Ten months are not a year. The data cannot say whether the same pattern holds in other seasons, and it has no history yet, so it says nothing about how far ahead to book.
- Each month shows one fare, the cheapest found; a month without a fare is a month nobody searched or found one.
The cheapest month on each route
Sources
Cheapest fares by month and by destination from the Aviasales Flight Data API, as described on How we read fares. No other source is used.