Krabi Diving Season: Best Months & Sites by Month
Plan Krabi diving by month: when Hin Daeng and Hin Muang open, what green season really means, and which sites suit your certification level.
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Last updated November 2026: Krabi diving season splits into a dry-season peak from November to April and a green season from roughly June to October. Hin Daeng and Hin Muang usually open from mid to late October until April, and both need Advanced Diver level. Ao Nang's islands, Phi Phi and Shark Point stay workable in between, and our Krabi diving guide covers the wider picture.
Featured image: (c) portioid, some rights reserved (CC BY-SA), CC BY-SA 4.0, via Wikimedia Commons.
Krabi Diving Season at a Glance
The Andaman Sea gives you two phases. From November to April the dry season brings the most settled seas, and the farther pinnacles at Hin Daeng, Hin Muang and Koh Haa run most regularly. From June to October the southwest monsoon brings rain, rougher crossings and more cancelled departures. Day trips to nearer reefs still go on calmer days. Do not copy Phuket's Similan rules onto Krabi. The Similan national park is officially open 15 October to 15 May, but that calendar covers a different area.
| Phase | Months | What changes | Best for |
|---|---|---|---|
| Best | November to February | Most settled seas; far sites run regularly | Advanced divers, big-site day trips |
| Shoulder | March to April, plus late October | Far sites still open; weather less predictable | Open Water divers, flexible travelers |
| Green season | June to October | Fewer boats; trips depend on the sea; far sites closed for part of it | Beginners, budget travelers, divers with spare days |
Month-by-Month Krabi Diving Calendar
Sea surface temperature in the Andaman typically stays near 28°C (82°F) to 30°C (86°F) all year, which is why season here is about sea state and access rather than cold water. You can check measured data in the NOAA sea surface temperature archive. Daytime air highs around 32°C (90°F) are common on the coast. Our Krabi water temperature guide helps you pick an exposure suit.
| Month | Rating | Reliable sites | Suits |
|---|---|---|---|
| January | Best | Ao Nang islands, Phi Phi, Shark Point, Hin Daeng, Koh Haa | All levels |
| February | Best | Same as January | All levels |
| March | Good | Same as January | All levels |
| April | Good | Ao Nang islands, Phi Phi, Shark Point, Hin Daeng until season end | Open Water and up |
| May | Mixed | Phi Phi, Ao Nang islands, Shark Point on calmer days | Flexible divers |
| June to August | Mixed to limited | Nearer sites on calmer days | Beginners, patient divers |
| September | Limited | Nearer sites only; Hin Daeng and Hin Muang not diveable mid-month | Divers with buffer days |
| October | Mixed, improving | Nearer sites; Hin Daeng and Hin Muang usually reopen mid to late month | Advanced divers watching park notices |
| November to December | Best | All main sites | All levels |
Which Dive Sites Are Open When
Match the site to the month before you pick a shop. Hin Daeng and Hin Muang sit in national park waters, so check current notices on the national parks department portal. Our Krabi dive sites guide goes deeper on each reef. Operators use "verify" for any window they have not confirmed with the park, so treat the entries below the same way.
Similan's 15 October to 15 May window covers a different area. Treat Hin Daeng's mid to late October opening as the Krabi date to track.
| Site | Usually diveable | Level | What to expect |
|---|---|---|---|
| Ao Nang islands | Most of the year, weather permitting | Ask the operator | Small reefs close to shore |
| Phi Phi Islands | Most of the year; daily trips run | Ask the operator | Reefs and sheltered bays |
| Shark Point, Anemone Reef, King Cruiser Wreck | Weather permitting | Wreck often needs more experience; verify | Reef fish, a wreck, soft coral |
| Hin Daeng and Hin Muang | Mid to late October to April | Advanced Diver | Open-water pinnacles; no sightings guaranteed |
| Koh Haa | Mainly the dry season; verify | Verify with the operator | Walls and swim-throughs |
| Koh Lanta area | Mainly the dry season; verify | Verify with the operator | Day trips from Lanta |
Green Season Diving (June to October): Worth It?
Green season suits flexible divers. You gain quieter boats and lower hotel prices. You risk cancelled departures, rougher crossings and reduced visibility, and Hin Daeng and Hin Muang are not available in September. Phi Phi and Ao Nang's islands remain the realistic choices on calm days. Book trips after you arrive when you can. Keep one spare day in your schedule so a cancelled boat does not wipe out your plan.
Best Month for Your Level: Beginner, Open Water, Advanced
Discover Scuba Diving works in any month because the dives stay at nearby reefs and a cancelled day is easy to rebook. Open Water students should avoid November to February only if they want the quietest boats. A multi-day course also needs a buffer, so start it on day two or three of your stay, not on the last. Our PADI courses in Krabi guide explains the course structure. Certified Open Water divers get the widest choice from November to April. Advanced divers should aim for late October to April, when Hin Daeng and Hin Muang are open.
- Discover Scuba: any month, with a spare day.
- Open Water course: December to April for the calmest teaching days.
- Certified Open Water: November to April for Phi Phi and Shark Point.
- Advanced: late October to April for Hin Daeng and Hin Muang.
Costs, Time and Booking Trade-offs
Prices and hours checked November 2026. Krabi shops quote day trips from Ao Nang or Railay, so farther sites mean longer boat time and a higher fare. For comparison, a Phuket operator lists a Similan day trip at ฿5,600 and a two-day, one-night trip at ฿13,900. Those are Phuket departures, not Krabi fares. Read our Krabi diving price guide for local rates. Peak months fill earlier, so reserve far-site days ahead in December and January. Green season usually costs less and lets you book on arrival.
Phuket's Similan day trip at ฿5,600 is only a benchmark. Ao Nang is the simpler base, since most day-trip shops sit near the beach road.
Practical Logistics: Piers, Boat Times, Cancellations, No-Fly Rule
Ao Nang is the simpler base because most day-trip shops are close to the beach road. Browse the Krabi dive shops guide before choosing, or start with diving from Ao Nang. Railay needs a longtail boat, and the crossing depends on the tide, so allow extra time. The Railay dive center page covers that departure. Ask the shop how it handles sea-condition cancellations: refund, reschedule or credit. Follow Divers Alert Network guidance on the no-fly interval before any flight home.
Common Mistakes to Avoid
Four errors cause most disappointed bookings.
- Booking Hin Daeng or Hin Muang in the closed window, such as mid-September.
- Assuming Phuket's Similan season applies unchanged to Krabi.
- Starting a course in the last days of your trip.
- Expecting guaranteed manta or whale shark sightings.
Snorkelers Traveling With Divers
Snorkelers can join Phi Phi and Ao Nang island trips in the same months divers do. Green-season swells make crossings rougher, so choose calmer days and ask whether the shop runs a separate snorkel group.
Notes for your next dive trip
Optional updates to our Thai diving guides.
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