What to Wear in Siem Reap in December
Siem Reap in December: 31°C / 88°F afternoons, 21°C / 70°F nights and a half marathon that starts in front of Angkor Wat at 05:45 on Sunday 6 December.
- White fitted cotton shirt — long sleeves meet Angkor Enterprise's bare-shoulders rule and a 21°C dawn
- Stone linen wide-leg trousers — the code prohibits shorts above the knee in sacred places
- Pale sage short-sleeve midi dress — sleeves and a below-knee hem in one piece for a 31°C afternoon
- Red-and-white checked krama — on UNESCO's list since December 2024, and worn as a scarf
- Off-white chunky trainers — the code discourages high heels inside the temples
- Olive flap crossbody — the same code discourages backpacks inside the temples
- Shorts or a skirt above the knee — Angkor Enterprise prohibits both in sacred places
- A sleeveless top — the code prohibits bare shoulders, at Angkor Wat and every other temple
- A quiet Angkor Wat sunrise on Sunday 6 December — runners gather in front of the temple from 05:15
- A pass bought from anyone but Angkor Enterprise — tickets purchased elsewhere are not valid
December in Siem Reap starts in the dark. On Sunday 6 December the 31st Angkor Wat International Half Marathon sends its 21km field off at 05:45 from in front of Angkor Wat, and every runner is told to be there 30 minutes early. DWD's table for Siemreap-Angkor gives December the lowest mean high of the year, 30.6°C, and a night that falls to 20.7°C. Angkor Enterprise sets the dress terms: "Revealing clothes such as shorts and skirts above the knees and showing bare shoulders are prohibited in sacred places." Pack long sleeves, full-length linen and flat soles in white, khaki, stone and sage, with a red-and-white krama for the sun after 9am.
In December you share Angkor Wat's sunrise with half-marathon runners, so dress for the first gate at dawn: a long sleeve, a hem below the knee, flat soles and a checked krama for the walk back in the heat.
The capsule
01White fitted cotton shirt, long sleeves, buttoned cuffsYour dawn layer and your temple cover in one. Angkor Enterprise prohibits bare shoulders in sacred places, and a long sleeve settles that before you reach the first gate. At 05:45 the night is only just off its 20.7°C low, so cotton sleeves feel right; by 10am you roll the cuffs back. Fitted seams keep it neat under the krama.
02Khaki short-sleeve camp-collar shirtYour second top, for afternoons that reach 30.6°C on DWD's table. A short sleeve still covers the shoulder, which is what Angkor Enterprise's code asks of you, and the open camp collar lets air in at the neck. Khaki sits well on the stone trousers, so one more shirt gives you a second full outfit for a three-day pass.
03Stone linen wide-leg trousers, full lengthThe code's first named prohibition is shorts above the knee, and a full-length linen leg puts that question away at every temple on the pass. A wide cut lets air move as the day climbs from 21°C at dawn to 31°C in the afternoon. Stone sits under the white shirt and the khaki one alike, and takes the krama's red check without a clash.
04Pale sage short-sleeve linen midi dress, tie beltOne piece that meets both halves of the rule. Short sleeves cover the shoulder and the hem falls below the knee, so it passes at Bayon and Banteay Srei, which open at 7:30am, as easily as at Angkor Wat. Linen breathes at December's 64% mean humidity on DWD's table, and pale sage is the quiet colour beside a red krama.
05Red-and-white checked cotton krama, worn as a scarfCambodia's everyday cloth, two years on UNESCO's list this month. UNESCO inscribed the practices linked to krama on its Representative List in December 2024, and lists the scarf first among its everyday uses. Choose cotton, which UNESCO names alongside silk, in a red-and-white check, and knot it loosely at the throat once the sun clears the towers and the race crowd thins.
06White cotton bucket hatDecember brings 7.3mm of rain on about two days on DWD's table, so sun is the weather you dress for after 9am. A soft cotton brim shades your face and neck on the open ground between temples, then squashes into the crossbody when you are inside a gallery. White matches the shirt and reflects light, and the brass eyelets let heat out at the crown.
07Off-white chunky trainers with stone suede panelsAngkor Enterprise's code discourages high heels inside the temples, and a race-day morning means a 05:15 arrival, a sunrise and three temples before lunch. A thick, cushioned sole takes the stone approach and steep temple steps, and laces hold your foot on the climb. Off-white with stone panels repeats the trousers, so the whole outfit stays in one light family.
08Olive waxed-canvas flap crossbodyBackpacks sit on the code's discouraged list beside heels, so carry the day at your hip. The flap holds your pass, and it is worth protecting: a 1-day pass costs $37, and only Angkor Enterprise sells valid ones, from its ticket office on Road 60. Waxed olive canvas copes with the odd shower in a month of two rain days, and it suits khaki and sage.
Day to night
Race morning, as a spectator. White fitted shirt · stone wide-leg trousers · red-and-white krama · white bucket hat for after sunrise · off-white trainers · olive crossbody. Angkor Wat opens at 5:00am; the 21km goes at 05:45, the 5km at 06:10, the 3km fun run at 06:25 and the 10km at 06:40, and sunrise comes at about 6:12am in the first week.
Banteay Srei, then dinner. Pale sage midi dress · khaki camp shirt in the bag · off-white trainers · white bucket hat · olive crossbody. Banteay Srei lies 25km north-east of the main temples and closes at 5:30pm; sunset comes at about 5:40pm in mid-December, and the night falls toward 21°C.
A suggested look — white fitted cotton shirt, red-and-white checked krama scarf, stone linen wide-leg trousers, white cotton bucket hat, off-white chunky trainers.
What to avoid
- Shorts or a skirt above the knee at any temple on the pass
- A sleeveless top in Angkor's sacred places
- Heels or a backpack inside the temples
- A quiet Angkor Wat sunrise on race morning, Sunday 6 December
- A pass bought from anyone but Angkor Enterprise
Frequently asked questions
Hot by day, mild before dawn and nearly dry. Deutscher Wetterdienst's (DWD) climate table for Siemreap-Angkor gives December a mean high of 30.6°C, the lowest of the year, and a mean low of 20.7°C, with 7.3mm of rain, about two days with any measurable rain and 64% relative humidity. NOAA's daily records for the airport, 2006–2020, give 30.5°C and 21.8°C. Cambodia publishes no English normals, so DWD's table is the reference. Sunrise moves from 6:12am on 1 December to 6:27am on the 31st, and sunset from 5:35pm to 5:48pm.
A white fitted cotton shirt, a khaki camp-collar shirt, stone linen wide-leg trousers, a pale sage short-sleeve midi dress, a red-and-white checked krama, a white cotton bucket hat, off-white chunky trainers and an olive crossbody. That covers Angkor Enterprise's dress rule, a 05:15 start in front of Angkor Wat on race morning and a 31°C / 88°F afternoon in the sun. Leave shorts, sleeveless tops and heels at home: the code prohibits the first two in sacred places and discourages the third.
Yes, but you share it. The 31st Angkor Wat International Half Marathon runs on Sunday 6 December 2026, and the organisers tell every participant to be at the race point in front of Angkor Wat at least 30 minutes before their start. The 21km and the wheelchair race go at 05:45, the 5km at 06:10, the 3km fun run at 06:25 and the 10km at 06:40. Registration closed on 23 October, so you are there as a spectator. Angkor Hospital for Children calls it "one of Cambodia’s biggest community events of the year since it first started in 1996". The organisers state its purpose: "Runners from all over the world participate to support a ban on the manufacture and inhumane use of antipersonnel mines." No spectator or road-closure notice had been published by late October, so check the race page before you fix the morning.
Early December has the race and a reopening; late December has a holiday. Race packs are handed out from 3 to 5 December at Angkor Century Resort and Spa, and the half marathon fills the area in front of Angkor Wat on Sunday the 6th. APSARA reports that West Mebon, the island temple in the West Baray, has finished a 14-year, US$12 million Cambodian–French restoration, and writes: "The official inauguration ceremony, marking the opening of the restored temple to visitors, is scheduled for November 2026." Treat it as due to reopen and check before you go. Peace Day, Tuesday 29 December, is a public holiday on the 2026 calendar. Sunrise slips from 6:12am to 6:27am across the month.
December has the lower high, January the lower low. DWD's table gives December 30.6°C by day and 20.7°C at night against January's 31.7°C and 20.4°C, so neither month is simply the cooler one. January is drier, 3.7mm of rain against 7.3mm, and less humid, 59% against 64%. The bigger difference is the crowd. Angkor Enterprise sold 87,936 passes to foreign visitors in December 2025 and 93,491 in January 2026; a season earlier the figures were 125,349 and 146,140. December has the race on the 6th. Our January guide plans the busier month around Angkor Wat's 5:00am opening.
A krama is Cambodia's checked cloth, and since December 2024 it has been on UNESCO's Representative List of the Intangible Cultural Heritage of Humanity, by decision 19.COM 7.B.27, taken in Asunción. Cambodia added it to its own national inventory in 2019. UNESCO describes it plainly: "A rectangular cloth made of either cotton or silk, krama features a variety of grid-pattern motifs." Its white, yellow, red and blue dyes come from plants and insects, and it is woven by hand on a traditional loom. The uses are everyday ones: "krama is used daily through all walks of life, as a scarf, belt, blanket, bandana, lower garment, decorative cloth, and hammock for children." As a visitor, wear yours as a scarf, with covered shoulders underneath.
Sources
- Deutscher Wetterdienst (DWD) — climate normals, Siem Reap stationDeutscher Wetterdienst's climate table for Siemreap-Angkor: temperatures 1997–2010, rain days (0.1 mm or more) 2006–2010. Cambodia publishes no English normals.
- Deutscher Wetterdienst — Klimatafel von Siemreap-Angkor / Kambodscha (48966): temperatures 1997–2010, precipitation 1981–2009, rain days 2006–2010 — accessed 2026-10-26
- NOAA NCEI — Global Summary of the Day, Siem Reap (48966099999): daily maxima and minima, 2006–2020 — accessed 2026-10-26
- Angkor Enterprise — Angkor Visitor Code of Conduct: dress code, high heels and backpacks, monks — accessed 2026-10-26
- The 31st Angkor Wat International Half Marathon, 6 December 2026 — official registration page (start times, race packs) — accessed 2026-10-26
- AIMS — Angkor Wat International Half Marathon race calendar (Sun 6 December 2026) — accessed 2026-10-26
- Angkor Hospital for Children — Angkor Wat International Half Marathon 2026 — accessed 2026-10-26
- Angkor Enterprise — Angkor Wat: opening hours 5:00am–5:30pm — accessed 2026-10-26
- Angkor Enterprise — Available tickets: 1-, 3- and 7-day Angkor passes, entry from 5:00am, the only valid seller — accessed 2026-10-26
- Angkor Enterprise — Bayon: opening hours 7:30am–5:30pm — accessed 2026-10-26
- Angkor Enterprise — Banteay Srei (consecrated 22 April 967, red sandstone, 25 km north-east of the main group) — accessed 2026-10-26
- APSARA National Authority — West Mebon restoration completed after 14 years; inauguration scheduled for November 2026 (20 October 2026) — accessed 2026-10-26
- Andersen Cambodia — Sub-Decree No. 167: 2026 public holidays (Peace Day, 29 December) — accessed 2026-10-26
- Angkor Enterprise — Monthly Angkor Pass statistics (December 2025, January 2026) — accessed 2026-10-26
- UNESCO — Cultural practices and expressions linked to Krama, a traditional woven textile in Cambodia (inscribed 2024, 19.COM) — accessed 2026-10-26
- UNESCO — Decision 19.COM 7.B.27 (Asunción, 2024): krama inscribed; on Cambodia's national inventory since 2019 — accessed 2026-10-26
