January is the coolest month in the north and the peak of the beach season on the Andaman coast. Below are Thai Meteorological Department (TMD) normals for ten stations, TMD’s outlook for January 2027, the PM2.5 watch periods, national park status, hotel occupancy and events with confirmed dates. Checked on 25 October 2026.
January weather by region: TMD normals
These are 1991-2020 normals from the TMD report; the Krabi station (48 563) has a shorter 1994-2020 record. A rainy day means 0.1 mm or more. Khao Lak uses the nearest TMD station, Takua Pa (individual beaches may differ). Koh Phangan and Koh Tao have no TMD station, so Samui is the nearest reference. Hotel occupancy is from the Ministry of Tourism and Sports (MOTS) for the whole province, not a resort: January 2025, the latest January in the MOTS file.
| Region, TMD station | High, °C | Low, °C | Rain, mm | Rainy days | Hotel occupancy Jan 2025, % |
|---|---|---|---|---|---|
| Phuket (Phuket, 48 564) | 33.0 | 25.0 | 49.9 | 5.6 | 86.41 |
| Khao Lak (Takua Pa, 48 561) | 32.6 | 22.1 | 62.1 | 6.3 | 79.31 (Phang Nga) |
| Krabi (Krabi, 48 563, 1994-2020) | 32.6 | 21.5 | 96.8 | 7.7 | 77.07 |
| Koh Lanta (Ko Lanta, 48 566) | 32.6 | 24.1 | 31.0 | 3.9 | 77.07 (Krabi) |
| Koh Samui, Phangan, Tao (Ko Samui, 48 550) | 29.0 | 24.2 | 126.8 | 11.1 | 81.97 (Surat Thani) |
| Pattaya (Phatthaya, 48 461) | 30.6 | 23.5 | 16.3 | 2.5 | 82.12 (Chon Buri) |
| Hua Hin (Hua Hin, 48 475) | 29.9 | 22.8 | 25.0 | 1.9 | 77.72 (Prachuap Khiri Khan) |
| Bangkok (Bangkok Metropolis, 48 455) | 32.7 | 23.4 | 23.6 | 2.6 | 82.67 |
| Chiang Mai (Chiang Mai, 48 327) | 30.0 | 15.7 | 11.3 | 1.3 | 89.92 |
| Chiang Rai (Chiang Rai, 48 303) | 28.6 | 13.8 | 16.5 | 2.0 | 88.16 |
TMD outlook for January 2027
TMD issued its cool season outlook on 9 October 2026. For January:
| Region | Minimum temperature | Rain |
|---|---|---|
| Upper north | 17-19 °C | light rain in places |
| Bangkok and suburbs | 23-25 °C | light rain in places |
| East including the coast (Pattaya) | 22-24 °C | light rain in places |
| South, Andaman coast (Phuket, Krabi) | 24-26 °C | rain over 10-20% of the area |
| South, Gulf coast (Samui) | 23-25 °C | rain over 20-40% of the area, heavy in places, mostly in the lower south |
TMD expects heavy rain on the Gulf side of the south to last until early January, and then to decrease. The coldest spell in the north is expected from late December to early February, with dense fog possible in December and January. In January and February westerly waves coming from Myanmar may bring thunderstorms, gusts and local hail to the upper part of the country. TMD expects El Niño to strengthen, so the season may be warmer than usual. The outlook runs until mid-February 2027 and will be updated in the last week of October.
Where to go in January
Phuket, Khao Lak, Krabi, Koh Lanta. Dry and busy: 31.0 mm on Koh Lanta, 49.9 mm in Phuket, 62.1 mm at the Takua Pa station near Khao Lak and 96.8 mm in Krabi, on 3.9-7.7 rainy days. Highs are around 33 °C and TMD expects rain over only 10-20% of the Andaman coast. January was Phuket’s busiest month of 2025, see Phuket by month and Krabi.
Koh Samui, Koh Phangan, Koh Tao. Better than December but still the wettest place in the table: 126.8 mm on 11.1 days, against 263.1 mm in December. TMD expects rain over 20-40% of the Gulf coast, mostly in the lower south. February is drier (64.3 mm). More in the Koh Samui holiday guide.
Pattaya and Hua Hin. Dry: 16.3 mm on 2.5 days and 25.0 mm on 1.9 days. Nights are 23.5 and 22.8 °C. The PM2.5 watch period starts in January: January to March for the east and January to April for the west.
Bangkok. 23.6 mm on 2.6 days, highs of 32.7 °C. The Bangkok Art Biennale runs until 28 February 2027. January is in PCD’s PM2.5 watch period for Bangkok and its suburbs (November-March).
Chiang Mai and Chiang Rai. The coolest month of the year: nights of 15.7 °C in Chiang Mai and 13.8 °C in Chiang Rai, highs of 30.0 and 28.6 °C, almost no rain (11.3 and 16.5 mm). Hotels were 89.92% and 88.16% full in January 2025. The PM2.5 watch period for the north runs from January to May, see below.
PM2.5 watch periods: where air quality needs attention in January
PCD’s notice of 10 August 2026 gives each region a period of increased attention to PM2.5:
| Region | PM2.5 watch period |
|---|---|
| Bangkok and suburbs | November-March |
| Central region | November-May |
| East (Chon Buri, Pattaya) | January-March |
| West (Prachuap Khiri Khan, Hua Hin) | January-April |
| North and northeast | January-May |
| South (Phuket, Krabi, Samui) | July-September |
Provinces in brackets are our mapping to PCD’s regions. PCD names traffic, burning of agricultural waste, forest fires, industry and cross-border haze as the main sources. A watch period is not a daily forecast and does not mean smoke every day. The TMD station in Chiang Mai records haze on 18.7 days in January, but haze is a visibility observation and not a PM2.5 measurement. How to check a station and plan around it: Chiang Mai smoke season.
National parks and islands in January
| Park | Status in January 2027 | Source |
|---|---|---|
| Ang Thong Marine Park (Samui) | open (annual closure 1 November-15 December) | DNP |
| Similan Islands | open (annual closure 16 May-14 October) | DNP |
| Surin Islands | open (annual closure 16 May-14 October) | DNP |
| Maya Bay, Phi Phi | open (annual closure 1 August-30 September) | DNP |
| Ko Rok (Lanta) | open (annual closure 16 May-15 November) | DNP park page |
The table is from the Department of National Parks (DNP) closure list for 2026, with data as of 7 January 2026. Parks can change their rules, so check with the park before you book a trip. The 2027 table is not published yet, so we use the annual periods from the 2026 table.
Events in January 2027
| Event | 2027 date | Where | Source |
|---|---|---|---|
| New Year’s Day | Friday 1 January, bank holiday | nationwide | Bank of Thailand |
| Bangkok Art Biennale | until 28 February | Bangkok: temples, museums, public spaces | TAT |
The Bank of Thailand’s list for 2027, announced on 17 August 2026, has no other holiday in January. In 2026 an additional special holiday was added on 2 January, and we have not found one announced for 2027. As of 25 October TAT had not published its January 2027 calendar, and we will add events when it appears.
Hotel occupancy in January
MOTS counts occupancy by province, not by resort, and it is not a price. January 2025: Phuket 86.41% (the highest month of that year), Chiang Mai 89.92%, Chiang Rai 88.16%, Bangkok 82.67%, Chon Buri, the province of Pattaya, 82.12%, Surat Thani, the province of Samui, 81.97%, Phang Nga, the province of Khao Lak, 79.31%, Prachuap Khiri Khan, the province of Hua Hin, 77.72%, and Krabi 77.07%. We do not publish accommodation prices until we collect our own dated measurements.
Should you go to Thailand in January?
Yes for a dry beach holiday on the Andaman coast, in Pattaya and in Hua Hin, and for cool days in Chiang Mai and Chiang Rai. Plan for peak-season crowds, and check air quality if you visit the north, Pattaya or Hua Hin. Koh Samui is better from February. The month before is covered in Thailand in December, the month after in Thailand in February. How beaches change by region and month is covered in Thailand beaches.
FAQ
Is January a good time to visit Thailand?
For most of the country, yes. January is dry and cool in the north (Chiang Mai 11.3 mm), dry in Bangkok, Pattaya and Hua Hin, and mostly dry on the Andaman coast (Koh Lanta 31.0 mm, Phuket 49.9 mm). The trade-offs are peak-season crowds, the start of the PM2.5 watch period in the north and east, and rain on Koh Samui (126.8 mm).
Where is Thailand dry in January?
By TMD normals it is driest in Chiang Mai (11.3 mm), Pattaya (16.3 mm), Bangkok (23.6 mm) and Hua Hin (25.0 mm). Koh Lanta gets 31.0 mm, Phuket 49.9 mm, Khao Lak (Takua Pa station) 62.1 mm, Krabi 96.8 mm and Samui 126.8 mm.
How cold is northern Thailand in January?
TMD normals give 30.0 °C by day and 15.7 °C at night at the Chiang Mai station, and 28.6 and 13.8 °C at Chiang Rai. TMD expects minimum temperatures of 17-19 °C in the upper north in January 2027, a warmer season than usual, with frost possible on mountain tops.
Is there smoke or haze in Thailand in January?
PCD sets a PM2.5 watch period from November to March for Bangkok and its suburbs, January to March for the east, January to April for the west and January to May for the north and northeast. A watch period is not a daily forecast: check an Air4Thai station on the day.
Is the sea calm in Thailand in January?
TMD expects waves of 1-2 m in the Andaman Sea through the 2026-2027 cool season. On the Gulf side TMD expects waves of 2-4 m at times until early January, with rain easing afterwards. Follow the beach flag on any coast.
Is Koh Samui good in January?
Better than in December, but still wet by Thai standards: 126.8 mm on 11.1 days by TMD normals, against 263.1 mm in December. TMD expects rain over 20-40% of the Gulf coast in January 2027, mostly in the lower south. February is the island's driest month (64.3 mm).
Sources
- TMD. Climatological Data for the Period 1991-2020 (stations 48 303, 48 327, 48 455, 48 461, 48 475, 48 550, 48 561, 48 563, 48 564, 48 566)
- TMD. Cool season outlook 2026-2027 (issued 9 October 2026), PDF pp. 1-4
- MOTS. Tourism statistics by province 2025 (xlsx)
- PCD. Regional PM2.5 risk periods, 10 August 2026
- Air4Thai. Official air quality map
- DNP. National park closures 2026 (data as of 7 January 2026)
- DNP. Mu Ko Lanta National Park (Ko Rok season)
- Bank of Thailand. Notification No. 37/2569, holidays for 2027 (unofficial English translation)
- Bank of Thailand. Financial institutions holidays 2026
- TAT. Bangkok Art Biennale 2026 (29 October 2026 to 28 February 2027)
- TAT. October event and calendar 2026 (published 29 September 2026)
Found an error or outdated fact? Tell the editors, we will fix it and update the check date.