Best Time to Visit Siem Reap: Heat, Rain and Angkor

When is the best time to visit Siem Reap?

December and January are the best months for most visitors: WMO averages show almost no rain and the coolest nights of the year. November and February are good shoulders. March to May is the hottest stretch, with May averaging 35.3°C, and September is the wettest month, averaging over 300 mm of rain.

Siem Reap is hot all year. The WMO averages for Siem Reap never show a monthly average high below 30.7°C, so the cool season is cool only by comparison. What really changes through the year is rain: under 10 mm a month from December to February against 305 mm in September.

For Angkor, the season decides how you split each day rather than whether you can go. Angkor Enterprise sells passes for entry from 05:00 to 18:30 (Angkor Enterprise tickets), so in every season the best temple hours are the first three and the last two of the day.

If you are still deciding how long to stay or which pass to buy, read is the Angkor temple pass worth it and is Angkor Wat sunrise worth it alongside this page.

What is Siem Reap’s weather month by month?

Highs stay between about 31°C and 35°C all year, so the real variables are rain and humidity. December to February average under 10 mm of rain a month; the monsoon builds from May and peaks at 305 mm in September. April and May are the hardest months for long temple days.

Figures come from the World Meteorological Organization’s World Weather Information Service for the Siem Reap station, where the published series runs from 1982 to 2024. They are averages: a dry-season shower or a dry week in August is entirely possible.

Read the rain column as a guide to disruption rather than to comfort. Even the dry months reach 31–32°C by day, and the wettest months are no cooler, so sun protection and water matter in every season.

Why are December to February the easiest months?

Because they combine the least rain with the coolest nights: December averages 7.4 mm of rain, January 4.3 mm and February 3.8 mm, with lows around 20–21°C. Days still reach 31–32°C, so temple time is best before about 10:00 and after 15:00. Book refundable rooms early for Christmas and New Year dates.

Dry ground matters beyond comfort. The outer sites sold separately by Angkor Enterprise, such as Koh Ker ($15), Beng Mealea ($10) and Kbal Spean ($5), lie well beyond the main park (Angkor Enterprise tickets), and those journeys are simplest in the dry months.

Cooler mornings also make sunrise worthwhile. If you buy a one-day pass for the next day after 16:45, Angkor Enterprise lets you enter that evening for sunset and still use the pass for the full following day (Angkor Enterprise FAQ), a useful trick on a short dry-season trip.

Families benefit too: children under 12 do not need a ticket, though they may be asked for a passport as proof of age, and they are not allowed to climb Angkor Wat’s steep upper tower.

How hot is Siem Reap from March to May?

Very. WMO averages put highs at 34.6°C in March, 34.8°C in April and 35.3°C in May, with lows near 24°C, so nights bring little relief. Temple days still work if you start at the 05:00 opening, retreat from late morning to mid-afternoon, and return for the last hours before closing.

Plan the heat into the pass you buy. A 3-day pass ($62) can be used on any three days within a week, and a 7-day pass ($72) within 30 days (Angkor Enterprise tickets), which lets you do shorter morning visits on more days instead of a single punishing marathon.

April also brings Khmer New Year, a three-day national holiday, which in 2027 falls in April under the sub-decree signed on 16 September 2026 (Cambodianess, 19 September 2026). Holiday crowds and peak heat together make it the most demanding time to visit.

Dress for the temples rather than the weather. The FCDO says visitors can be refused entry to religious sites, including Angkor Wat, in skirts or shorts above the knee, and should cover bare shoulders; light, loose, long layers solve both problems.

Is the rainy season a bad time for Angkor?

Not necessarily. June to August average roughly 170–195 mm of rain a month, far below September’s 305 mm, and the countryside around the temples is green. September and October are the riskiest months: the most rain falls then, and outer-temple trips and lake boat rides are most likely to be disrupted.

A flexible pass is the best wet-season insurance. With the 7-day pass valid for 30 days, you can wait out a stormy morning instead of losing a paid day (Angkor Enterprise tickets). Keep sunrise plans loose and decide the night before.

Roads are the bigger hazard than temples. The FCDO says Cambodia has one of the highest road-accident rates in south-east Asia, that travel after dark significantly increases the risk, and that mined areas are often unmarked, so stay on main routes in rural areas, including around temple complexes.

The Chong Kneas boat rides on the Tonlé Sap are sold only at the counter, 11.4 km from the city, from $28 for a small boat carrying one to five people; Angkor Enterprise suggests sunset departures between 16:30 and 17:15 (Angkor Enterprise boat rides).

Which holidays affect a Siem Reap trip in 2026 and 2027?

Three long national breaks matter most: the Water Festival on 23–25 November 2026 and 12–14 November 2027, Khmer New Year over three days in April 2027, and Pchum Ben on 29 September–1 October 2027. Temples and roads can be busier with domestic visitors then, so book rooms and transport early.

The 2026 dates come from Sub-Decree No. 167, issued on 18 September 2025 (Andersen Cambodia); the 2027 dates come from the sub-decree signed on 16 September 2026, which sets 22 public holidays (Cambodianess). The exact April 2027 dates for Khmer New Year were not given in that report.

Siem Reap marks the Water Festival with its own events: Angkor Enterprise’s gallery shows the tourism minister opening the 2025 Angkor Water Festival in Siem Reap (Angkor Enterprise). Check local event listings if you want to join the celebrations or avoid them.

Which Angkor pass suits each season?

In the dry season, a 3-day pass ($62, valid on any three days within a week) lets you split temples into cool mornings and late afternoons. In hot or wet months, the 7-day pass ($72, valid within 30 days) gives room to dodge heat and storms. The 1-day pass costs $37.

Angkor Enterprise says a 1-day pass is built around the Small Circuit, including Angkor Wat, Bayon, Ta Prohm, Banteay Kdei and Phnom Bakheng, while 3-day and 7-day passes add the Grand Circuit, including Preah Khan, Neak Pean, Ta Som, East Mebon and Pre Rup (Angkor Enterprise FAQ). Multi-day passes need a photo; the 1-day pass does not.

Buy from the official site or the Angkor Pass app, and screenshot the ticket. Koh Ker, Beng Mealea and Kbal Spean need their own tickets, so add them only on dry, early-start days (Angkor Enterprise tickets). Our Angkor temple pass guide weighs the options in more detail.

What should you know about arrival and safety before you pick dates?

Flights now use Siem Reap–Angkor International Airport (SAI), which opened on 16 October 2023 about 55 km from town, so allow for a longer transfer. Air arrivals must submit Cambodia’s free e-Arrival card within seven days before landing. The FCDO advises against all but essential travel within 20 km of the Thai border.

SAI replaced the old Siem Reap International Airport when seven regional airlines moved across on its opening day (TTR Weekly). For entry, the FCDO says tourist visas last 30 days, recommends applying for an e-visa at least four days ahead, and confirms that visas on arrival are available for a photo and a fee in US dollars.

The border warning follows heavy fighting along parts of the Thailand–Cambodia border in 2025; a ceasefire was signed on 27 December, but land crossings remain suspended and border-area temples such as Preah Vihear are closed (FCDO). Check the FCDO map before booking any trip north of the Angkor park.

In town, the FCDO notes bag snatching by passing motorbikes, advises tuk-tuks with protective grills, and reports sexual assaults on lone women by men claiming to be motorbike taxi drivers around Pub Street. Use booked transport at night in every season.

Who should go to Siem Reap when?

Choose by your tolerance for heat and rain. First-timers and families do best from December to February; travellers who like green landscapes and have flexible plans can aim for July and August; festival seekers should time trips to Khmer New Year in April or the Water Festival in November and accept busier roads and temples.

The table pairs each type of trip with the months that suit it, using the WMO averages above and the official holiday dates. Whatever the month, plan temple time around the 05:00 opening and the last hours before 18:30.

For where to base yourself and how to pace the temples, continue with where to stay in Siem Reap and the Siem Reap 3-day itinerary.

So when should you go to Siem Reap?

Go in December or January if you can, November or February if you cannot, and July or August if you want greenery and can live with rain. Avoid April and May unless you handle heat well, and keep September and October for flexible travellers with spare days on a 7-day pass.

Whatever the month, hold a refundable room until your flights are fixed, and check whether the hotel includes a transfer from SAI, which sits well outside town. For longer stays, the Siem Reap 7-day itinerary and things to do in Siem Reap help you fill the extra days.

Sort mobile data before you land with eSIM vs pocket Wi-Fi vs roaming; you will need it for the e-Arrival card, the Angkor Pass app and booking rides at night.