What to Wear in Bangkok in January

Hot in the afternoon, warm at night, with very little rain. The Thai Meteorological Department's (TMD) normals for its Bangkok Metropolis station give January an average high of 32.7°C / 91°F and a low of 23.4°C, with 23.6mm of rain on about two days and 67.9% relative humidity. Thailand's seasons page, sourced to the meteorological department, puts winter "between mid-October and mid-February", but an average January night stays above the 22.9°C top of TMD's cool band. Sunrise holds between 6:41am and 6:45am all month, and sunset moves from 6:01pm on 1 January to 6:17pm on the 31st.

A teal long-sleeve linen shirt, a white knit polo, pale sand linen trousers, a saffron tiered midi skirt, a sand linen shirt-dress, tan leather slides, a white N95 and a sand bucket bag. That covers Wat Pho's rules, two more temple venues on the Biennale route, a guided morning at the Jim Thompson House and a 33°C afternoon. Leave the shorts at home; Wat Pho prohibits them above the knee for women.

Temple clothes, because three of the venues are temples. TAT lists Wat Arun, Wat Pho and Wat Prayoon among the 2026 venues, alongside Museum Siam, the Bangkok Art and Culture Centre, One Bangkok, centralwOrld, Siam Paragon, the National Museum Bangkok and the Art Centre at Silpakorn University. The fifth edition runs from 29 October 2026 to 28 February 2027 under an Angels & Mara theme. Temple rules come from the temples: Wat Pho asks for polite dress, bars shorts above the knee for women and has you leave your shoes on a shelf, and covered shoulders and knees are the safe choice at Wat Arun and Wat Prayoon. TAT's governor, Thapanee Kiatphaibool, framed the edition this way: "Bangkok Art Biennale 2026 reflects TAT’s direction to position Thailand as a high-value and meaningful destination, where culture, creativity and contemporary identity create deeper reasons to travel."

Early January has the holidays and the families. New Year's Day, Friday 1 January, is the month's only bank holiday on the Bank of Thailand's 2027 list; the next is Monday 22 February. Saturday 9 January is National Children's Day, set on the second Saturday of January by a 1965 cabinet resolution, and last year Government House opened to families from 8am to 3pm. In mid-January last season, PM2.5 averaged 55.18 µg/m³ from 12 to 15 January 2026 against a 37.5 standard, according to the Bangkok Metropolitan Council's record, so check Air4Thai whatever the date. Late January brings longer evenings, with sunset at 6:17pm on the 31st, and the Biennale stays open until 28 February.

December is cooler, drier and less humid. TMD's normals give January 32.7°C by day and 23.4°C at night against December's 32.3°C and 23.2°C, twice the rain (23.6mm on about two days, against 11.6mm on about one) and 67.9% humidity against 65.6%. Sunset moves from 5:53pm in mid-December to 6:09pm in mid-January. The calendars differ more than the weather. December is the old city's ceremonial month, with the Grand Palace closed on 5 December and the royal cremation ceremonies for Queen Sirikit The Queen Mother on 15–19 December; our December guide covers both. In January the palace calendar shows every day open as of late October, and the month belongs to the Biennale's temple venues.

It is the home of the American whose company, as the brand puts it, helped bring Thai silk to global prominence. The James H.W. Thompson Foundation dates the company: "In 1950, The Thai Silk Company was founded and it has become the leading exporter of Thai silk that soon became renowned worldwide." The brand's About page gives the same year, and its timeline credits Thai silk's appearance in The King and I (1956) with lifting demand. Thompson was awarded the Order of the White Elephant in 1962. He built the house in 1958–59 from old teak houses, across the klong from the Bahn Krua silk-weaving community, and it is open daily from 9am to 6pm on guided tours only. For the visit, the white polo and the sand trousers are enough.