Trip base · Thailand
Similan Islands
Four sites in the Andaman Sea, mostly dived by liveaboard from Khao Lak. Koh Bon has manta cleaning stations and Richelieu Rock is known for whale sharks. The national park closes every year from 16 May to 14 October.
Strong fit for February
28°C+
- Strength: Water 28–29°C in February
- Strength: 4 of 4 sites are in season in February
- Strength: Calm seas on almost every day
- Strength: Mostly dry: rain on about 1 day in 10
Pack a 3 mm wetsuit for February.
Why this match: 40 + 27 + 20 + 12 = 99
- Season40 / 40
- 4 of 4 sites are in season in February; calm on almost every day.
- Water27 / 27
- Average 29°C; your minimum is 28°C. Pack a 3 mm wetsuit.
- Your level20 / 20
- No level picked, so all 4 sites count.
- Weather12 / 13
- Rain on about 1 day in 10; no real storm risk.
Month by month
Season: best December to April. Marine life uses the same scale (Best = reliable, Good = likely, Possible = possible, Off = not seen; ? = we don't know yet). Water and rain are 1991–2020 averages.
| Month | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Season | January: Best | February: Best | March: Best | April: Best | May: Off season | June: Off season | July: Off season | August: Off season | September: Off season | October: Off season | November: Good | December: Best |
| Mantas | January: Likely | February: Likely | March: Likely | April: Likely | May: Possible | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: Possible | November: Likely | December: Likely |
| Whale sharks | January: Possible | February: Likely | March: Likely | April: Likely | May: Possible | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: Possible | November: Possible | December: Possible |
| Hammerheads | January: We don't know yet | February: We don't know yet | March: We don't know yet | April: We don't know yet | May: We don't know yet | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: We don't know yet | November: Possible | December: We don't know yet |
| Reef sharks | January: Likely | February: Likely | March: Likely | April: Likely | May: Likely | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: Likely | November: Likely | December: Likely |
| Turtles | January: Likely | February: Likely | March: Likely | April: Likely | May: Likely | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: Likely | November: Likely | December: Likely |
| Dolphins | January: We don't know yet | February: We don't know yet | March: Possible | April: Possible | May: We don't know yet | June: Not seen | July: Not seen | August: Not seen | September: Not seen | October: We don't know yet | November: We don't know yet | December: We don't know yet |
| Water | 28° | 29° | 29° | 30° | 30° | 29° | 29° | 29° | 29° | 29° | 29° | 29° |
| Rain days | 6 | 3 | 10 | 17 | 27 | 27 | 28 | 28 | 28 | 27 | 18 | 9 |
| Calm days | 31 | 28 | 31 | 30 | 28 | 24 | 22 | 22 | 26 | 29 | 29 | 30 |
| Storm risk | – | – | – | – | – | – | – | – | – | – | 7% | – |
Rain days: days with 1 mm or more in the ERA5 grid cell (about 30 km across); over tropical seas it counts more light-rain days than a local rain gauge would. Calm days: waves under 1.5 m and wind under 25 km/h. Storm risk: share of years with a named storm within 250 km that month (– means under 5%).
Dive sites here
4 sites on Divetip. Today's Dive scores are for reference only: live scores cover the next 48 hours, not your trip month.
Getting there
Fly to Phuket (HKT). Road to Thap Lamu pier, where most liveaboards leave: about 1 h.
Liveaboard or day boat.
What diving costs
A day of diving from about €136
A day of diving
Sea Bees Diving (MC Stingray, Khao Lak): THB 5,600 for 2 dives (about €149)
Similan Islands day trip (Thu-Sun, Islands 5-9); Koh Bon/Koh Tachai days 5,800 THB, Richelieu Rock 6,000 THB. Includes tanks, weights, lunch, coffee/tea/water/fruit, divemastering, free pick-up from Khao Lak/Bang Niang/Pakarang. Excludes Similan National Park fee (diver 700 THB, non-diver 500 THB); equipment rental listed separately (full set 750 THB). Schedule valid 01.11-30.04 (year not stated).
Sunrise Divers (Sundancer catamaran, from Khao Lak): THB 5,100 for 2 dives (about €136)
2-dive Similan day trip (Islands 5-9 or Koh Bon); Tuesday 3-dive trip (Koh Tachai, Koh Bon, Premchai Wreck) 6,500 THB. Includes breakfast, lunch, soft drinks, transfers from Khao Lak. Excludes equipment (900 THB), National Park fee (700 THB diver / 500 THB non-diver, cash on board), Phuket transfer (2,400 THB per car one way). Season November-April (year not stated).
Wetzone Divers (Khao Lak): THB 6,800 for 2 dives (about €182)
'Day trip (2 dives) all inclusive from 6.800 THB'. Lunch included; page does not itemise whether park fee, equipment or transfers are in the price.
Liveaboards
Oceanic Dive Center (Manta Queen 1/3/6/7): THB 21,500 for 4 nights (about €574)
4 days/4 nights, 15 dives, 4-berth cabin (twin/double 23,500). Includes equipment rental. National Park fees extra (4 days 1,800 THB). Undated; page shows other conflicting figures (e.g. 'Prices start at 25,500').
Wetzone Divers (MV Manta Queen 2): THB 20,000 for 3 nights (about €534)
4 days/3 nights, 10 dives, 4-bed non-ensuite (twin/double 22,000). National park fees 2,300 THB and equipment (600 THB/day) extra. Departures Oct 2026-May 2027.
Wetzone Divers (MV Bavaria): THB 35,900 for 3 nights (about €958)
4 days/3 nights, 13 dives to Koh Bon, Koh Tachai, Richelieu Rock and Surin, Standard Twin (Similan-only 4D/3N 10 dives from 26,500). Fuel surcharge and park fees extra 'depending on the safari length'; equipment 600 THB/day.
Prices as published by each operator (a few by a named booking agent), read on 8 November 2026. Euro amounts at the ECB reference rate of 6 November 2026. Park fees, permits and equipment are often extra. Prices change, so check with the operator before you book.
Non-divers: snorkeling by boat only
Snorkeling is by boat only: speedboat snorkel day trips from Khao Lak visit the islands' beaches and reefs between mid-October and mid-May, and non-divers can also ride along on dive day boats for a reduced fare.
Sources: discoverykhaolak.com, sunrise-divers.com
Book your Similan Islands trip
- Find Similan Islands trips on Klook (partner link, opens in a new tab)
- Search flights on Aviasales (partner link, opens in a new tab)
Partner links: we may earn a commission if you book, at no extra cost to you. Partners never change the ranking.
Where this comes from
- Water temperature: NOAA OISST v2.1 daily sea surface temperature, 1991–2020.
- Storms: NOAA IBTrACS tracks, 1991–2020. Rain, waves and wind: ERA5 reanalysis, 1991–2020. Contains modified Copernicus Climate Change Service information 2026.
- Coral heat stress: Bleaching Watch (The water is warmer than its usual warmest month, NOAA's lowest heat-stress level. Satellite data, highest level in the 7 days to 7 November 2026.) Coral bleaching: NOAA Coral Reef Watch daily 5 km Bleaching Alert Area (7-day maximum), checked twice a day.
- Seasons by site: our dive site pages. Getting there: transfer source.
Marine life sources (6 species)
- Mantas: bluewaterdivetravel.com, dive-the-world.com, mantatrust.org, thailand.prd.go.th
- Whale sharks: dive-the-world.com, bluewaterdivetravel.com, thethaiger.com, divephotoguide.com, thailand.prd.go.th
- Hammerheads: notroublesjustbubbles.com, thailand.prd.go.th
- Reef sharks: oceanicdivecenter.com, bluewaterdivetravel.com, thailand.prd.go.th
- Turtles: bluewaterdivetravel.com, oceanicdivecenter.com, thailand.prd.go.th
- Dolphins: 12go.asia, nationthailand.com, thailand.prd.go.th
Typical values are 1991–2020 averages and our site seasons. Always check local conditions with your dive centre. Spotted something wrong? Report a correction.