Siem Reap (Angkor) weather in May

May in Siem Reap: sweltering, rainy, with muggy air — a gamble, with 20 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Siem Reap🇰🇭 Cambodia · Southern Vietnam & Cambodia · City53
  1. 80Jan
  2. 77Feb
  3. 65Mar
  4. 58Apr
  5. 53May
  6. 62Jun
  7. 56Jul
  8. 60Aug
  9. 49Sep
  10. 51Oct
  11. 68Nov
  12. 78Dec

#10 of 12 months in Siem Reap · #1257 of 1413 destinations to visit in May · comfort 53/100 (tier D)

Days
35°C
Nights
26°C
Wet days
20
Sun
10.4 h
Humidity
76%
Daylight
13 h
Siem Reap, Cambodia
Photo: Antonio Serra · Pexels

Traveller notes on Siem Reap in May

Other months in Siem Reap

Regulars are direct that temperatures here are essentially guaranteed to top 35C this month, though generally less humid than the peak of July, with the standard workaround being an early start, a midday retreat to a pool and air conditioning, then heading back out again late in the afternoon. Our row backs that hot, genuinely dry read, 35C reading as a scorching 40C, over 24.3C nights feeling 28C, with rain light at 36.9mm across 6.4 days and humidity at 65 percent. Regulars are consistent some visitors do manage this month and even April despite the intensity, while others avoid it deliberately, the temples themselves offering little shade regardless of timing. Sun protection and a genuinely early start remain the standard advice throughout. The record: 11 hours of sun, a 13.1 kph wind and AQI 78.
GuaranteedOver35CEarlyLateSchedule · March · 1 month ago · Read more on Tripadvisor ↗
Siem Reap-forum threads asking if April is simply too hot don't sugarcoat it - one thread calls the month stinking hot, brain-bakingly hot, everything parched, brown and dusty, with daytime temperatures well into the 40s Celsius on the worst days. Regulars offer the same standing advice: start sightseeing at first light, retreat for a long midday siesta somewhere air-conditioned with a pool, then go back out in the late afternoon once the worst heat breaks. A tuk tuk ride is recommended over an enclosed car, since the breeze dries off sweat rather than trapping heat the way air conditioning does when you step back out. Khmer New Year lands in April too, and mango season is in full swing. The midday temples empty out fast as visitors retreat indoors. The record: a scorching 35.3C by day feeling like a punishing 41C, 25.4C nights, 74mm across 10 days, 67 percent humidity, an unhealthy 77 AQI and 11 hours of sun.
AngkorAprilRegular · April · 1 month ago · Read more on Tripadvisor ↗
Siem Reap-forum threads on November weather call it the downhill side of the wet season - locals treat November through January as their cold season, bundling up for the mornings until around 9:30 or 10am even though visitors mostly find it warm rather than cold. The standard itinerary follows that same schedule: Angkor tours start around 8am while it's still cool, wrapping up by midday once it gets too warm to keep walking. The monsoon is winding down but still unpredictable enough that a poncho is standard advice, with any downpour usually arriving in a concentrated morning or evening window rather than spread through the day. Posters call the November-to-mid-January stretch one of the best climate windows of the year, which is exactly why it's also peak season. The record: 31.5C days feeling like a sticky 37C, 23.6C nights, 98mm across 12.9 days, 79 percent humidity and 9.4 hours of sun.
AngkorEarlyMorningRegular · November · 1 month ago · Read more on Tripadvisor ↗
February is the last comfortable month at Angkor. It is firmly inside the dry season - our row gives 15.5mm across 2.9 days - and the mornings are still among the year's coolest, which matters when the plan is a sunrise at the temples. What regulars warn about is the dust, because months without rain leave the roads and the causeways powdery, and about the direction of travel: February is where the temperature begins its climb towards 39 or 40C by April. Tonle Sap still has enough water for the boat trips in this month, which stops being true later. It is high season, so the temples are busy. The record: 32.8C days that feel like 36C, 21.9C nights, humidity 61 percent and 10.6 hours of sun.
DustyButStillCoolMornings · February · 1 month ago · Read more on Tripadvisor ↗

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Siem Reap climate normals — May

Daytime high35°C / 95°F🔥 sweltering
Nighttime low26°C / 78°F
Feels like (high)42°C / 108°F
Rainfall140 mm / 5.5 in🌧 rainy
Rainy days20 days
Humidity76%💦 very humid
Dew point25°C / 77°F
Sunshine10.4 h/day
Daylight12.7 h
Wind12 km/h / 7 mph
Air quality (US AQI)58🙂 moderate

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Siem Reap in May

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Quietschool holidays in 2 of the markets that fill it, one of its worst months for weather(estimated)

JFMAMJJASOND

Peak crowdsBusyShoulder seasonQuiet

Best months for Siem Reap's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Toughest weatherSiem Reap's weather peaks December–February, best around January.

JFMAMJJASOND

Best weatherFair weatherToughest weather

What's on in Siem Reap in May

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Season

    Southwest monsoon

    15 May – 31 Oct · usually

    Afternoon rain, empty temples in the mornings and the moats full enough to give the reflections the postcards use. The unpaved roads out to the far temples are the catch.

What's on around the world in May →

Where is Siem Reap?

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Siem Reap in May — FAQ

Is May a good time to visit Siem Reap?
May in Siem Reap: sweltering, rainy, with muggy air — a gamble, with 20 rainy days. It ranks #10 of 12 months for Siem Reap on SeasonMap's comfort score (53/100).
What is the weather like in Siem Reap in May?
In May, Siem Reap averages a daily high of 35°C and a low of 25.7°C, with about 140.4 mm of rain over roughly 20.3 rainy days.
What is the air quality in Siem Reap in May?
Siem Reap has a mean US Air Quality Index of about 58 in May.