Siem Reap in May

In May, Siem Reap averages 34°C (93°F) during the day and 25°C (77°F) at night, with around 11 days of rain (170 mm total).

Off-peak

Conditions are very hot — early-morning and evening sightseeing recommended. Plan for unsettled weather and bring rain gear.

May in Siem Reap is outside the typical sweet spot for sightseeing weather. It can still be a great time to visit if you have specific reasons (festivals, off-season pricing, etc.).

34°C
Avg high
25°C
Avg low
11
Rain days
170 mm
Rainfall

How May compares to the rest of the year in Siem Reap

3rd
warmest month of the 12
6th
wettest month of the 12
10%
of yearly rainfall falls in May
12 h 44 min
daylight on the 15th

May is one of the warmest months in Siem Reap (3rd of 12) and moderately rainy compared to the rest of the year (6th of 12). Daytime temperature runs 2°C above the annual average (33°C). May runs 1°C cooler than April (35°C) and cools 1°C in June (33°C).

May sunrise & sunset in Siem Reap

🌅
Sunrise (15th)
5:38 AM
🌇
Sunset (15th)
6:23 PM
Day length
12 h 44 min

Times shown for Siem Reap local time (Asia/Phnom_Penh), calculated for the 15th of May. They shift by a few minutes day to day across the month.

Photography light in Siem Reap — May

Golden-hour and blue-hour windows for the 15th of May, in Siem Reap's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).

🌅 Blue hour (AM)
4:38 AM – 5:18 AM
🌄 Golden hour (AM)
5:18 AM – 6:18 AM
🌇 Golden hour (PM)
5:43 PM – 6:43 PM
🌆 Blue hour (PM)
6:43 PM – 7:23 PM
Milky Way galactic core
Good
Galactic core is up but lower on the horizon; head well outside city limits for a clean view.

📅 When to book — Siem Reap in May

Travel writers usually only tell you when to go. Here's when to book flights and lodging for the best mix of price and availability, based on May's tier (Off-peak) and Siem Reap's popularity.

✈ Flights — lead time
3-6 weeks
Cheapest flights of the year. Last-minute deals are real if you can be flexible.
🏨 Lodging — lead time
2-4 weeks
Last-minute bookings work fine. Some seasonal properties close — call ahead if it's a small boutique or beach resort.

Crowds & pricing — May in Siem Reap

Off-peak

This is off-peak for Siem Reap — the lowest prices of the year and the fewest crowds, but with real trade-offs: some restaurants, hotels, and beach businesses may close for the season; weather conditions can make outdoor activities unpredictable; and a handful of seasonal sights run reduced hours or close entirely. Great if you prefer a quiet local rhythm and don't mind the climate giving you reasons to choose indoor activities.

Why this tier: challenging tourism weather

Sun & mosquito risk — May in Siem Reap

☀️ UV Index (noon, 15th)
12.9
Extreme
Stay indoors during midday hours; SPF 50+ even briefly outside, UPF clothing, wide-brim hat, sunglasses essential.
🦟 Mosquito risk
●●●●●
Severe
Severe mosquito season with active disease transmission risk. DEET 30%+, picaridin 20%, long sleeves day and night, treated nets, and check CDC/WHO travel advisories before going.

UV is a clear-sky sea-level estimate — clouds, altitude, and reflective surfaces (snow, water) shift it ±30%. Mosquito risk is climate-derived only; for current disease advisories (dengue, malaria, zika) check the CDC or WHO travel pages before your trip.

Siem Reap in other months

MonthAvg highAvg lowRainfallRain daysSnow days
January 32°C / 90°F 20°C / 68°F 5 mm 1 0
February 33°C / 91°F 21°C / 70°F 5 mm 1 0
March 35°C / 95°F 23°C / 73°F 30 mm 3 0
April 35°C / 95°F 25°C / 77°F 90 mm 7 0
May 34°C / 93°F 25°C / 77°F 170 mm 11 0
June 33°C / 91°F 25°C / 77°F 210 mm 15 0
July 32°C / 90°F 25°C / 77°F 200 mm 16 0
August 32°C / 90°F 25°C / 77°F 230 mm 18 0
September 31°C / 88°F 25°C / 77°F 275 mm 18 0
October 31°C / 88°F 24°C / 75°F 260 mm 15 0
November 31°C / 88°F 23°C / 73°F 135 mm 9 0
December 31°C / 88°F 21°C / 70°F 30 mm 3 0

Other cities with similar May weather

🌍 See the full ranked list of climate twins for Siem Reap in May →

Frequently asked questions

How hot is Siem Reap in May?

In May, Siem Reap averages a high of 34°C (93°F) and a low of 25°C (77°F) — generally hot.

Does it rain a lot in Siem Reap in May?

May can be fairly wet in Siem Reap, with about 11 rainy days on average.

Is May a good time to visit Siem Reap?

May is hot. It suits travelers who are comfortable with hot weather; check the month-by-month ranking to compare it against the rest of the year.

What should I pack for Siem Reap in May?

Pack lightweight, breathable clothing, sunglasses and sunscreen, plus a compact umbrella or rain jacket. See the full May packing list for Siem Reap for a complete, climate-based checklist.

Open Siem Reap on the interactive map

Check the live 10-day forecast and sunrise/sunset.