Andaman sea conditions vary by season and by day. The historical regional wave series below has higher monthly median daily maxima in June–September than in February–April. It cannot predict conditions on a specific ferry crossing, establish which route is safest, or guarantee that a sailing will operate.
Historical regional wave heights by month
These are published historical model statistics for 2015–2024, not current observations or route forecasts. A median daily maximum is the middle value of the daily maximum wave heights in that month’s sample; it is not the height throughout an average ferry trip.
| Month | Median daily maximum | Days reaching 1.25 m in the regional model |
|---|---|---|
| January | 0.78 m | 7% |
| February | 0.73 m | 5% |
| March | 0.57 m | 1% |
| April | 0.56 m | 3% |
| May | 0.91 m | 32% |
| June | 1.45 m | 66% |
| July | 1.55 m | 72% |
| August | 1.49 m | 68% |
| September | 1.30 m | 54% |
| October | 0.85 m | 22% |
| November | 0.77 m | 11% |
| December | 0.89 m | 21% |
The series describes seasonal variation in the sampled region, not a promise of calm weather in March or a cancellation forecast for July. December is not the lowest month in this particular statistic. Tourist demand, timetable availability and wave conditions are different measures.
What this means for planning a ferry trip
Check date-specific departures, rather than assuming an operator’s seasonal timetable guarantees a seat. For October travel, our October ferry-planning guide covers itinerary and booking checks. The best-time guide puts ferry planning into a seasonal context.
Do not use the monthly table to choose a “safe” boat, rank routes for roughness or assume all morning sailings are calmer. The model grid is too coarse to resolve individual channels. Local shelter, the vessel and conditions on the day can affect the actual crossing; this dataset does not quantify those effects.
If motion sickness is a concern, read our comfort guidance and ask a pharmacist or clinician about your circumstances. No operator or ticket class guarantees a nausea-free journey.
Weather advisories and cancellations
For current information, consult the INCOIS ocean-state forecast, official weather advisories and your operator’s sailing updates. A historic monthly average is not a substitute for those checks. Do not infer a cancellation or a safe crossing solely from the distance of a storm on a map.
Sailings may change for weather, port restrictions, technical or operational reasons. Follow the port and crew instructions. For a BookYourFerry booking, the published cancellation policy explains passenger cancellations and operator-cancelled sailings; operator-direct and government tickets have separate terms.
Avoid a tight ferry-to-flight connection. Returning to Port Blair before the day of your flight creates a buffer, but prolonged disruption can exceed one day. Confirm practical alternatives with your operator and accommodation provider rather than relying on a guaranteed rebooking or flight connection.
Frequently asked questions
Which months have lower historical regional wave heights?
March and April have the lowest median daily maximums in this published 2015–2024 series, followed by February. That does not predict conditions on your travel date.
Does the monsoon table tell me whether my ferry will be cancelled?
No. We have not established a cancellation probability from this wave dataset. Check current advisories and operator updates.
Which Andaman ferry route is roughest?
This regional model cannot resolve the routes well enough to answer that question. Do not read its wave heights as measurements inside individual channels.
Is a ferry suitable for children or older travellers?
Suitability depends on the traveller, accessibility needs and conditions. Confirm boarding assistance and seating with the operator, and seek individual medical advice where needed. A monthly climate statistic is not a personal safety assessment.
Methodology and limits
The existing published series attributes its wave figures to NOAA/NCEP WAVEWATCH III: hourly significant wave height for 2015–2024, reduced to a maximum per IST day and monthly summaries. The model grid is approximately 55 km. It cannot resolve individual ferry channels or establish conditions experienced on board. The historical numeric values are retained here, not newly recomputed or independently validated in the September 2026 wording review.
Download the published monthly CSV. Figures do not establish real-time conditions, future schedules, route-level safety or the percentage of trips cancelled. Guidance and methodological qualifications updated 17 September 2026.