In 2023–2025, 4,816 of 62,838 records are marked cancelled: 7.7%. September has the largest monthly share in this subset. That does not support a blanket rule that winter is always riskier. Route composition and prolonged cancellation runs can affect the totals.
Why these three complete years?
2023, 2024 and 2025 are the latest three complete calendar years in the frozen archive. All 1,096 dates have records. The archive starts in February 2018 and ends in September 2026, so those partial years are not pooled here. There are 43 empty source dates in 2021. We show 2020–2022 separately below; keeping them separate does not certify that later years were uninterrupted or normal.
| Month | Cancelled / records | Share | Observed days | Directions / vessel types | Status conflicts |
|---|---|---|---|---|---|
| January | 193 / 3,993 | 4.8% | 93 | 11 / 2 | 0 |
| February | 439 / 3,523 | 12.5% | 85 | 10 / 2 | 0 |
| March | 64 / 3,765 | 1.7% | 93 | 14 / 2 | 0 |
| April | 240 / 4,738 | 5.1% | 90 | 18 / 3 | 0 |
| May | 253 / 5,003 | 5.1% | 93 | 16 / 3 | 0 |
| June | 146 / 6,295 | 2.3% | 90 | 29 / 3 | 6 |
| July | 304 / 7,931 | 3.8% | 93 | 36 / 3 | 99 |
| August | 693 / 8,109 | 8.5% | 93 | 31 / 2 | 149 |
| September | 975 / 6,366 | 15.3% | 90 | 31 / 2 | 251 |
| October | 576 / 4,982 | 11.6% | 93 | 22 / 2 | 183 |
| November | 555 / 4,231 | 13.1% | 90 | 14 / 2 | 1 |
| December | 378 / 3,902 | 9.7% | 93 | 13 / 2 | 0 |
Primary and web status disagree on 689 records in this subset, including 251 in the September group. They remain in the denominator and are counted by the primary field. The chart therefore describes that source field, not verified causes or the cancellation experience of every passenger.
The same month does not repeat the same result every year
| Month | 2023 | 2024 | 2025 |
|---|---|---|---|
| January | 32 / 1,455 · 2.2% | 138 / 1,190 · 11.6% | 23 / 1,348 · 1.7% |
| February | 285 / 1,300 · 21.9% | 12 / 1,035 · 1.2% | 142 / 1,188 · 12.0% |
| March | 43 / 1,415 · 3.0% | 7 / 1,052 · 0.7% | 14 / 1,298 · 1.1% |
| April | 105 / 1,544 · 6.8% | 99 / 1,696 · 5.8% | 36 / 1,498 · 2.4% |
| May | 69 / 1,611 · 4.3% | 170 / 1,713 · 9.9% | 14 / 1,679 · 0.8% |
| June | 68 / 2,057 · 3.3% | 45 / 2,206 · 2.0% | 33 / 2,032 · 1.6% |
| July | 51 / 2,544 · 2.0% | 211 / 3,086 · 6.8% | 42 / 2,301 · 1.8% |
| August | 139 / 2,458 · 5.7% | 422 / 3,340 · 12.6% | 132 / 2,311 · 5.7% |
| September | 358 / 1,945 · 18.4% | 566 / 2,622 · 21.6% | 51 / 1,799 · 2.8% |
| October | 137 / 1,318 · 10.4% | 405 / 2,015 · 20.1% | 34 / 1,649 · 2.1% |
| November | 325 / 1,294 · 25.1% | 90 / 1,420 · 6.3% | 140 / 1,517 · 9.2% |
| December | 220 / 1,199 · 18.3% | 39 / 1,308 · 3.0% | 119 / 1,395 · 8.5% |
Why do route and vessel composition matter?
| Source direction | Records | Share of all records | Observed days |
|---|---|---|---|
| Yalova → Pendik | 11,773 | 18.7% | 1,096 |
| Pendik → Yalova | 11,654 | 18.5% | 1,096 |
| Yalova → Yenikapı | 9,338 | 14.9% | 1,096 |
| Yenikapı → Yalova | 9,337 | 14.9% | 1,096 |
| Other 34 directions | 20,736 | 33.0% | — |
| Year | Source vessel type | Records | Share within year |
|---|---|---|---|
| 2023 | Deniz Otobüsü | 6,552 | 32.5% |
| 2023 | Feribot | 29 | 0.1% |
| 2023 | Hızlı Arabalı Vapur | 13,559 | 67.3% |
| 2024 | Deniz Otobüsü | 8,681 | 38.3% |
| 2024 | Hızlı Arabalı Vapur | 14,002 | 61.7% |
| 2025 | Deniz Otobüsü | 6,180 | 30.9% |
| 2025 | Hızlı Arabalı Vapur | 13,835 | 69.1% |
There are 36 observed directions in July and 10 in February. The overall monthly rate therefore does not compare an identical route and vessel mix. See the weekday and departure-time analysis for a comparison holding one direction and vessel type fixed.
Read earlier years separately
| Year | Cancelled / records | Share | Observed days |
|---|---|---|---|
| 2019 | 1,017 / 29,080 | 3.5% | 365 |
| 2020 | 7,202 / 27,140 | 26.5% | 366 |
| 2021 | 1,712 / 22,200 | 7.7% | 322 |
| 2022 | 4,606 / 26,911 | 17.1% | 365 |
Prolonged cancellation runs remain in these tables. A separate weather study excludes March–July 2020 and specified long interruptions; its rate cannot replace this one. The source contains no cancellation reason, so monthly differences cannot be labelled as storm, pandemic, holiday or demand effects.
Sources, method and checking a sailing today
Cancellation counts use the primary status “İptal Edildi”. The cancellation-share denominator is every record in the stated group; status conflicts are disclosed separately. Missing dates do not create invented sailings. Sales tables use the separately defined eligible completed records.
Full archive methodology · Sources and attribution · Official IDO information
These are record-based summaries, not totals of physical sailings, unique passengers or weather-caused cancellations. We do not publish raw CSV/JSON files or record-level data. Verify today’s journey separately by date, direction and time.
Sources and data
İDO: official sailing and ticket information · MGM: Marmara marine forecast
Cite this page
When using this analysis, please credit Sefer İptal and link to this page. İDO supplies the sailing records; Sefer İptal prepares the explanations and calculations on this page.
Sefer İptal. Which months have more IDO cancellations? A 2023–2025 comparison. 2026-09-17. https://seferiptal.com/en/guides/ido-seasonal-cancellations/