Koh Samui weather, right now and for the rest of your trip

On Samui

A prolonged dry spell (El Nino cited) emptied local raw-water sources and cut tap-water production by about 40 percent. Disruptions reported from 27 July, worst in higher areas. The PWA Samui branch started rotating supply (a yellow zone and a red-green zone) for seven days from 3 August; some communities had weak pressure or no running water for several days and families bought tanker water. Whether rationing went on after the first seven days: unverified.

Impact

Demand about 34,000 m3/day against about 16,000 m3/day through the mainland pipeline (shortfall 18,000). PWA trucked 16,000 m3/day from its Surat Thani branch and added 4,000 m3/day via the underwater pipeline; a damaged reverse-osmosis plant was being repaired; cloud seeding was requested; hotels and larger businesses bought tanker water in peak season. Deputy Interior Minister ordered a long-term water security plan.

Sources: pattayamail.com, aseannow.com, bluewin.ch. Confidence: verified (3 sources).

On Samui

Cold air over the Gulf with easterly and southeasterly winds converging. Waves about 1-2 m on Chaweng and Lamai (above 2 m in thunderstorms); lifeguards and hotels raised red flags and swimming was banned along the whole shoreline because of rip currents.

Impact

Ferries to and from Samui kept running, delays possible; forecast to last until 20-21 Feb. No damage reported.

Sources: khaosodenglish.com. Confidence: verified (1 source).

On Samui

Surat Thani-Koh Tao and return ferries were suspended 19-21 Nov for strong winds and high waves; Lotus, Lomprayah and express boats also cancelled single sailings. A TAT-based update of 27 Nov says tourists on Ko Samui, Ko Pha-ngan and Ko Tao enjoyed uninterrupted activities with hotels, transport and attractions operating normally despite strong winds and waves, and airports in the region were operating with limited delays.

Impact

The disaster was elsewhere: Hat Yai had 335 mm in one day on 21 Nov 2025 (heaviest in at least 300 years), Thailand at least 297 deaths (229 in Songkhla) from Cyclone Senyar, a rare Malacca Strait system. The ferry notice also quoted a forecast of over 1,000 mm in ten days for the region (a forecast, not a Samui measurement).

Sources: pattayamail.com, pattayamail.com, en.wikipedia.org. Confidence: verified for ferries and TAT status; Samui rainfall unknown (GHCN file ends 23 Aug 2025).

On Samui

Samui station Tmax 37.9 C on 1 Jun 2025 (highest since 38.0 C on 11 Apr 2016). Days at or above 36 C: 23 in 2025 up to 23 Aug, 14 in 2024, 15 in 2023, against 0 to 6 in most earlier years; days at or above 35 C: 50 in 2025 up to 23 Aug. Other 2023-25 peaks: 37.7 (5 Jul 2023), 37.3 (28 Jun 2023, 15 Jun 2024), 37.2 (20-21 May 2023).

Impact

Long-term monthly record highs (TMD extremes since 1968, via Wikipedia): Jan 33.4, Feb 35.1, Mar 36.0, Apr 38.0, May 37.8, Jun 38.2, Jul 37.7, Aug 37.2, Sep 36.4, Oct 35.8, Nov 34.0, Dec 32.3 C. A travel blog says 37.2 C in May 2023 broke the island record; the station file shows higher values earlier (38.0 in 2016), so that claim is unverified. Missing days in the file mean counts are lower bounds.

Sources: ncei.noaa.gov, en.wikipedia.org. Confidence: verified from station file; blog record claim unverified.

On Samui

Station: 87 mm on 12 Dec, 96 mm on 13 Dec, 207.8 mm on 14 Dec (largest daily total in the file since 28 Mar 2011), 81 mm on 16 Dec; 530 mm on 10-17 Dec (8 days of data). The Department of Mineral Resources issued a landslide warning for Samui sub-districts on 14 Dec. About 04:30 and 05:40 on 15 Dec two landslides hit a villa-construction workers' camp on Himatong Soi, Moo 1, Maret sub-district (hillside); two Myanmar workers (aged 19 and 39) were found dead 10 m away; work suspended. On 16 Dec Surat Thani declared eight districts disaster areas, including Koh Samui and Koh Phangan, after three days of heavy rain plus runoff from the Nakhon Si Thammarat range.

Impact

2 deaths (landslide). A Thaiger headline reports 8 villas collapsing at Merit Resort Samui after rain and a landslide on an early Saturday; its date could not be confirmed (it could be 14 Dec 2024 or 13 Nov 2021): unverified. Airport and ferry status in Dec 2024: not found.

Sources: khaosodenglish.com, pattayamail.com, ncei.noaa.gov. Confidence: verified (2 sources + station).

On Samui

M2.4 at 08:24 on 30 May (Ang Thong sub-district, 4 km deep; the Department of Mineral Resources linked it to geothermal energy), then two more on Saturday 1 June (Pattaya Mail: M2.4 and M2.2; the M2.2 struck at 08:31, 2 km deep, in Bo Phut). Felt by residents in Ang Thong, Bo Phut and Na Mueang; no damage, no aftershocks. The Natural Resources Minister ordered a seismometer for the island; seismology officials said Samui is geologically stable. Another M2.4 at 00:47 on 13 Nov 2025 (9.550N 99.956E) was heard as a loud boom and felt in Bo Phut.

Impact

None. Officials: unlikely to see significant seismic activity.

Sources: pattayamail.com, pattayamail.com, infoquest.co.th, thansettakij.com. Confidence: verified.

On Samui

Bangkok Post, 2 Jul 2023: low rainfall and high demand left the island with about 30 days of local freshwater; Phru Na Mueang and Phru Krajud reservoirs and the Hin Lad waterfall were sharply down; taps ran dry for days; locals paid 250-300 baht for about 2,000 litres. The deputy mayor asked residents and tourists to save water so the province would not declare a disaster zone; El Nino was expected to make it worse.

Impact

PWA stations could make about 15,000 m3/day and the 250-300 baht price came from the Bangkok Post piece (both seen only through a search summary, the page is paywalled); more underwater-pipeline supply from the mainland planned. SCMP (13 Jul 2023): the shortage dates from the mid-1990s.

Sources: dailyo.in, scmp.com, bangkokpost.com. Confidence: verified (secondary reports of Bangkok Post, which is paywalled).

On Samui

Station: 160 mm on 12 Nov and 152 mm on 13 Nov (467 mm on 9-15 Nov), 141 mm on 29 Nov, November total 1,079 mm (29 days of data). Surat Thani floods from 23 Nov hit 13 districts including the island districts Koh Samui and Koh Phangan; by 2 Dec 6,134 households (18,712 people) were affected across the province. Thaiger reports a hillside landslide that collapsed 8 villas at Merit Resort Samui on an unconfirmed Saturday (13 Nov 2021 was a Saturday): unverified.

Impact

AHA Centre 23 Nov-7 Dec: 70,771 households in 10 provinces, 2 deaths (1 in Surat Thani, 1 in Chumphon).

Sources: bangkokbiznews.com, adinet.ahacentre.org, floodlist.com, ncei.noaa.gov. Confidence: verified (province report + station); resort landslide date unverified.

On Samui

Russian tourist drowned off Koh Samui on 2 Jan ignoring warnings. On 3-4 Jan Bangkok Airways cancelled all Samui flights and Gulf ferries were suspended (2 days); Surat Thani airport closed from the afternoon of 4 Jan to Saturday noon; red flags and swimming bans on Samui, Phangan and Tao; NDWC alarms urged people in high-risk beach areas to move to higher ground. Waves up to 3 m reaching far inland on Samui (Al Jazeera), up to 5 m offshore (AFP); power blackout across swathes of Surat Thani and Nakhon Si Thammarat. About 20,000 tourists were stuck on Samui (island chief), 15,000 on Tao and 4,000 on Phangan (Khaosod; AFP said 10,000 on Phangan). The eye passed over Nakhon Si Thammarat (landfall Pak Phanang 12:45 on 4 Jan), so the islands avoided a direct hit. Station 124.5 mm on 4 Jan.

Impact

Flights and ferries resumed on Saturday 5 Jan, Bangkok Airways added extra flights. Thailand: 8 deaths (10 including Vietnam and Malaysia), about US$95 million damage; first tropical storm to make landfall in southern Thailand since Linda in 1997 (Wikipedia). A search summary of AP says over 28,000 people sheltered in seven provinces (unverified).

Sources: khaosodenglish.com, aljazeera.com, thejakartapost.com, theaseanpost.com. Confidence: verified (5 sources).

On Samui

Station 113 mm on 16 Dec (December total 669 mm). AHA Centre 18 Dec lists Ko Samui district among the eight Surat Thani districts flooded (with Tha Chang, Chaiya and others).

Impact

Worst on the mainland: Nakhon Si Thammarat 377 villages in 17 districts, 1 dead and 1 missing (FloodList, 16-18 Dec).

Sources: adinet.ahacentre.org, floodlist.com. Confidence: verified list entry; depth and damage unverified.

On Samui

Passenger boats from Don Sak pier to Koh Phangan and Koh Tao stayed suspended for a second day on Thursday 21 Dec with waves up to 4 m; boats to Koh Samui could still leave but daytime sailings depended on sea conditions; the governor ordered marine police to the pier. Typhoon Tembin (Vinta) was in the South China Sea on 24-25 Dec and hit southern Vietnam (Vietnam Airlines cancelled flights on 25 Dec); its path through the Gulf and any Samui effect are unverified. Samui station rain 27, 50 and 24 mm on 26-28 Dec.

Impact

No casualties found for Samui in this episode.

Sources: nationthailand.com, en.wikipedia.org. Confidence: verified for ferries (1 source); the later Tembin link is unverified.

On Samui

Rain from 1 Jan; station 44 mm on 4 Jan, 159.3 mm on 5 Jan, 56 mm on 6 Jan (352 mm on 1-8 Jan). Flooded roads and an overflowing lake on the island, tourists floating on inflatables, traffic snarled and flights to and from Samui delayed (AP, 5 Jan). Boat services between the Gulf islands (ferry, speedboat, longtail) discontinued until conditions improved; Na Muang and Hin Lat waterfalls closed on 6 Jan; a guesthouse owner called it the worst flooding on the island in over a decade; Samui and Phangan deluged in peak season (AFP, 6 Jan).

Impact

South-wide: 8 dead and 120,000 households by 6 Jan (AFP); at least 25 dead and 1.1 million affected by 10 Jan (Deccan Herald, seen only in a search summary); final 96 deaths, about 1.8 million people and roughly 120 billion baht damage across 12-13 provinces (Wikipedia, DDPM). Nakhon Si Thammarat airport shut for two days, main southbound road cut, trains stopped.

Sources: gulfnews.com, foxnews.com, en.wikipedia.org, 12go.com. Confidence: verified (4 sources).

On Samui

Rain from 1 Dec. On Sat 3 Dec the TMD Samui station measured 90.4 mm from the afternoon of 2 Dec; 17 spots on the ring road (Highway 4169) flooded, worst at Big C in Bo Phut about 1.2 m deep over 200 m and Chaweng (Wat Sawang Arom to the post office) about 50 cm over 1 km. Station daily totals: 175 mm (3 Dec), 144 mm (7 Dec), 493 mm on 1-10 Dec. By 6 Dec the Phru Chaweng swamp overflowed onto Chaweng Beach Road, 40-50 cm deep; hotels lost water and power; boats were laid on to reach the airport and flights were delayed, ferries kept running; Samui and Phangan were declared disaster areas. On Phangan a 20-ton boulder and four power poles blocked a road for about 4 hours. Officials blamed rubbish blocking drains, building across waterways and high tide slowing drainage; a shop owner on Chaweng said the water was under 1 m against over 2 m in 2011.

Impact

South-wide: 11 dead by 5 Dec, 14 by 7 Dec (2 in Surat Thani), 350,000 people in 10 provinces; parts of 11 provinces declared disaster zones; UK FCO warned of widespread flooding incl. Koh Samui and Koh Phangan.

Sources: matichon.co.th, thaipbs.or.th, matichon.co.th, khaosodenglish.com. Confidence: verified (6 sources + station).

On Samui

Koh Samui Waterworks office scrambled as taps ran dry in some areas after several months of low rainfall; untreated water available fell from 31,800 to 21,600 m3/day.

Impact

A raw-water pipe project was due to finish in 2016.

Sources: reliefweb.int. Confidence: verified (1 source).

On Samui

Downpour early on 26 Nov flooded many areas, some up to 30 cm; officials kept key tourist roads clear but most of the island flooded. District chief put staff on 24-hour alert. Station 105.2 mm on 26 Nov.

Impact

Samui-mainland ferries not disrupted, but surges up to 2 m were forecast. Heavy rain warned for the whole East and South until 28 Nov.

Sources: pattayamail.com. Confidence: verified (1 source + station).

On Samui

Station rain: 177 mm (27 Mar), 307 mm (28 Mar, the wettest March day on record), 252 mm (29 Mar), 147 mm (30 Mar) = 884 mm in four days and 1,069 mm in the seven days to 30 Mar; March total 1,137 mm against a normal 115 mm. Flash floods came down from the hills after days of rain; the mayor called it the worst in a decade (ScandAsia, seen only in a search summary). Samui airport suspended services indefinitely because roads around it flooded and a power blackout hit the airport; Bangkok Airways cancelled 36 flights on 28 Mar and all 53 on 29 Mar; ferries halted by 3 m waves between Samui and Surat Thani; FireFly suspended Subang flights. Bangkok Airways said about 2,000 people (mostly tourists) were stuck at the airport or in hotels; AFP-based reports put stranded tourists at 13,000 to 15,000. Flights and ferries resumed on 30-31 Mar; the mayor said 80 percent of the island was back to normal by 1 Apr, Chaweng the worst hit with pumps deployed.

Impact

At least 21 dead in the south by 30 Mar (3 along the Surat Thani coast); later tolls at least 53, roughly 9 million affected and over US$500 million damage (Wikipedia). Thai Airways flew three relief flights (600 passengers) and Bangkok Airways 19 flights (about 2,000 passengers). March normally brings about 115 mm over 4-5 days.

Sources: aljazeera.com, ttgasia.com, nbcnews.com, travelmole.com. Confidence: verified (5 sources + station).

On Samui

Station: 315.2 mm on 2 Nov (the biggest daily total at the station since 24 Nov 1988), 278 mm on 9 Nov, November total 1,113 mm and December 936 mm. On 2-3 Nov Samui airport suspended services after the runway flooded and Bangkok Airways could not say when service would resume (flights set to resume that afternoon, with a backlog); about 100 foreign tourists were stranded on Ang Thong island by high waves.

Impact

Thailand-wide 2010 floods: 232 deaths by 19 Nov, about 50 billion baht damage (Wikipedia); 76 deaths in the South.

Sources: c9hotelworks.com, en.wikipedia.org, ncei.noaa.gov. Confidence: verified for airport (2 sources); other impacts unverified.

On Samui

Heavy rain the night of 7 Nov flooded several locations; flood levels up to 1 m in parts of the commercial centre and tourist sites, 30 cm on the main road. Samui declared a disaster zone on Thursday 8 Nov. Airport suspended service that morning, more than 1,000 travellers stranded (hundreds per another line of the same text); weather had stopped aircraft from taking off since late Wednesday. Station 138 and 105 mm on 7-8 Nov (also 324 mm on 22-24 Oct 2007).

Impact

Ferries ran as usual. Authorities pumped water into rivers.

Sources: aseannow.com. Confidence: verified (Bangkok Post / TNA text on a forum; 1 source + station).

On Samui

After devastating the Philippines and southern Vietnam as Typhoon Durian, it entered the Gulf as a depression about 50 km east of Samui on 6 Dec and made landfall over Surat Thani and Nakhon Si Thammarat. Heavy rain on Samui, Phangan and Tao; all boat services halted except Samui ferries; about 5,000 tourists stranded on Phangan and Tao. Station 46 mm on 6 Dec and 45 mm on 8 Dec.

Impact

Local civil defence on standby for landslides. No Samui casualties found.

Sources: aseannow.com, en.wikipedia.org. Confidence: verified (1 source) + station.