Siem Reap Weather in May

🇰🇭 Cambodia

33°C

High

26°C

Low

Rain Days

11h

Sunshine

82%

Humidity

Asia › 🇰🇭 Cambodia › Siem Reap

Updated: March 2026

Is May a Good Time to Visit Siem Reap?

3/10

Avoid

May is a avoid time to visit Siem Reap (3/10). With 11 daily sunshine hours and only 22 rain days, this month delivers genuinely reliable outdoor conditions, ranking it 4th sunniest of the year in Siem Reap. May suits travellers visiting for indoor culture, food, and architecture rather than outdoor activities. Pack accordingly for 22 potential rain days. June offers a similar profile at lower hotel rates if dates are flexible. Watch out for prolonged rain stretches: with 22 wet days, a fully outdoor itinerary is risky. Build in museum days and covered market visits as contingency. Planning tips: most accommodation categories have availability, and last-minute deals are common. The quieter streets and shorter queues can make this a genuinely enjoyable time to visit for the right type of traveller. Budget-conscious visitors will find the best value of the year in this period.

vs April:34°C avg high

The single most important thing to know about visiting Siem Reap in May: rain is a genuine factor across 22 days of the month, meaning your plans need built-in indoor alternatives. Precipitation totals 154mm for the month, spread across roughly 22 days, and 11 sunshine hours per day give you a reliable window for outdoor plans.

33°C

Avg High

26°C

Avg Low

22 days

Rain Days

11h

Sunshine

82%

Humidity

Temperature in Siem Reap in May

The 7°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. At 82% humidity, the 33°C daytime high feels 2-4°C warmer in practice: quick-dry fabrics and shade-seeking between noon and 3pm are the sensible response. UV index averages 8 this month, classed as high to very high. SPF 30+ sunscreen, a brim hat, and sunglasses are not optional between 10am and 4pm. Winds are calm at an average 12 km/h, so wind-chill is not a factor in planning your clothing. In Fahrenheit: 91°F average high, 79°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).

Temperature in May

Monthly Precipitation (mm)

What to Wear in Siem Reap in May

Morning26°CBefore the day warms up

Afternoon33°CPeak daytime temperature

Evening29°CAfter sunset cools down

Packing for Siem Reap in May means dressing for 33°C days and 26°C evenings. A lightweight linen or cotton shirt with loose-fit trousers or a sundress handles the 33°C daytime heat. Evening temperatures settle at 26°C, a modest 7°C drop that a light cardigan or denim jacket covers. For footwear, breathable walking sandals work for casual exploration, but closed-toe trainers are better for uneven surfaces in the historic centre. With 22 rain days expected, a compact travel umbrella is worth the bag space. A waterproof jacket is better than an umbrella if you plan full-day outdoor routes. For temple and religious site visits, carry a lightweight scarf or sarong to cover shoulders and knees, required at most major sites across the region. At 82% average humidity, quick-dry synthetic or bamboo fabrics dry overnight and stay comfortable longer than cotton.

💡

Local tip: Loose-weave linen and moisture-wicking fabrics are the practical choice in Siem Reap's heat and humidity. Many shopping centres run air conditioning at near-arctic levels, so a thin layer in your bag prevents discomfort indoors.

Events in Siem Reap in May

May has no major festivals or public holidays in Siem Reap, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.

What to Pack for Siem Reap in May

Based on 33°C average highs and 22 rainy days

Lightweight breathable clothing
Linen or bamboo shirts for the hottest hours
Sun hat with a wide brim
UV-protective sunglasses
Hydration bottle (at least 1 litre)
Quick-dry travel towel
Anti-chafe balm for long walking days
Moisture-wicking synthetic fabrics for active days
Compact folding umbrella
Waterproof outer layer or packable rain jacket
Quick-dry clothing that recovers fast after a shower
SPF 30+ sunscreen
Comfortable walking shoes (a second pair lets the first air out overnight)
Universal travel adapter
Small day pack for city exploration
Reusable water bottle

Best Activities in Siem Reap in May

Early morning walk through Siem Reap's historic market districtBest before 9amTemperatures are still manageable at 29°C before the midday heat builds
Open-air rooftop dining at sunsetFrom 6pm onwardsThe 33°C daytime heat drops noticeably after sunset, making al fresco dining comfortable
Waterfront promenade or harbour walkEarly morning or after 5pmSea breezes cut through the humidity, making coastal routes the most pleasant in heat
Guided cycling tour of the old quarterFirst tour of the day (7-9am)The low-traffic window before tourist crowds and the cooler morning air make this the prime riding slot
Spend a morning in the national or city art museumOpens at 10am; arrive earlyWith 22 rain days expected, having a full-day indoor plan is practical insurance
Cooking class focused on regional cuisineHalf-day sessions run 10am-1pm or 3-6pmIndoor activity that fills a rainy half-day with genuine cultural content
Visit covered historical sites: cathedral, palace, or bazaarAny time; most crowded middayRoofed monuments and covered markets provide exploration without weather exposure
Visit the main botanical garden or city park at seasonal peakYear-round; best light in morningMay brings distinct seasonal changes to public green spaces worth exploring
Seek out chilled local specialities: cold-brew tea, ice desserts, or chilled seafood at street-level stallsAny time; most atmospheric in evening marketsHot-weather street food culture peaks in May, with vendors setting up specifically for warm evenings

Why is Siem Reap warm in May?

In May, Siem Reap sits in the dry season corridor, as the ITCZ shifts away from the region and trade winds bring drier, more stable air. This produces reliably sunny days reaching 33°C, with lower humidity than the wet months. Overnight lows of 26°C offer a pleasant reprieve from the midday heat. Climate data: Open-Meteo ERA5 (1991–2020).

Sunshine Hours

The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.

UV Index

A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate -- wear sunscreen. UV 6-7: High -- hat and SPF 30+ essential. UV 8-10: Very High -- limit midday exposure. UV 11+: Extreme -- seek shade between 10am-4pm.

Rain Days

A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.

Humidity

Relative humidity as a percentage. Below 40%: Dry -- skin and throat may feel parched. 40-60%: Comfortable -- ideal for most people. 60-80%: Sticky -- light, breathable fabrics recommended. Above 80%: Muggy -- heat feels more intense; quick-dry clothing is essential.

Frequently Asked Questions: Siem Reap in May

In May, Siem Reap experiences average highs of 33°C (91°F) and lows of 26°C (79°F). Expect around 22 rainy days and 11 hours of sunshine per day, with humidity averaging 82%. The 7°C gap between daytime and overnight temperatures is worth planning around: light layers work for most visitors during the day, but an overshirt or cardigan handles the cooler evenings. UV index averages 8, so sun protection is advisable on clear days.

Siem Reap typically sees 22 rainy days in May, with total precipitation of around 154mm. This is a notably wet period. A waterproof jacket or compact umbrella is essential, and it is worth building indoor alternatives into your daily itinerary for the inevitable rainy stretches. For context, the driest month in Siem Reap typically sees 4-6 fewer rain days than May.

Pack lightweight, breathable clothing (linen or cotton), a wide-brim sun hat, SPF 50+ sunscreen, and a refillable water bottle for Siem Reap in May. The 33°C daytime heat demands sun protection during midday hours, typically 11am to 4pm. A compact travel umbrella is also worth packing, as 22 rainy days means afternoon showers are a real possibility. Quick-dry synthetic fabrics are preferable to cotton in 82% humidity.

May is a reasonable time to visit Siem Reap. Expect 22 rainy days, so pack a light rain layer for flexibility. Average temperatures of 33°C make outdoor exploration comfortable during the dry periods. With 11 daily sunshine hours, there are reliable windows of good weather to plan outdoor activities around, even if the month is not the driest on the calendar.

The average high temperature in Siem Reap in May is 33°C (91°F), and the average low is 26°C (79°F). The mean daily temperature is approximately 30°C (85°F). The day-to-night range of 7°C is moderate, meaning a single light jacket covers most situations. These are 30-year climate normals based on the 1991 to 2020 reference period; individual years will vary, particularly in transitional months like spring and autumn.

The best month to visit Siem Reap is generally February. February offers the most sunshine at 11 hours per day and only 3 rainy days. Average temperatures reach 33°C, making it comfortable for sightseeing, outdoor dining, and exploring the city. If your travel dates are flexible, planning your trip around February gives you the best chance of dry, bright weather.

May is shoulder or low season in Siem Reap, meaning fewer tourists and generally lower prices than peak months. With 11 sunshine hours and 22 rainy days, the weather is less of a draw for mass tourism. This is an advantage for travellers who prefer a quieter, more relaxed experience with shorter queues and easier accommodation availability.

In May, Siem Reap suits a range of activities thanks to warm temperatures of 33°C. With frequent rain, indoor activities and covered attractions are a smart choice. Top options include exploring historic neighbourhoods, visiting museums and galleries, local food markets, and day trips to surrounding areas. With 11 hours of sunshine, parks and waterfront walks are particularly enjoyable.

May ranks 4th sunniest of the year in Siem Reap, with an average 11 daily sunshine hours. The driest months are January, February, and December. March is the hottest month (34°C avg high); September is the coolest (30°C). From here, temperatures fall 1°C into June. Compared to last month (April: 34°C high, 15 rain days), May is cooler and wetter. May sits in the middle of the annual sunshine ranking for Siem Reap, offering a reasonable balance of good weather and manageable crowds.

Year-Round Climate

Month	High	Low	Rain Days	Sun	Details
January	31°C	21°C	2	10h	View
February	33°C	23°C	3	11h	View
March	34°C	25°C	9	11h	View
April	34°C	26°C	15	11h	View
May	33°C	26°C	22	11h	View
June	32°C	26°C	21	10h	View
July	32°C	25°C	22	9h	View
August	31°C	25°C	25	9h	View
September	30°C	25°C	26	8h	View
October	30°C	24°C	23	9h	View
November	30°C	23°C	9	10h	View
December	30°C	21°C	3	10h	View

Other Months in Siem Reap

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Plan Your Trip to Siem Reap

Best Time to Visit Siem Reap Siem Reap vs Bangkok in May Siem Reap vs Ho Chi Minh City in May

Nearby Destinations with Similar Weather

These cities are within 500 km and experience broadly comparable weather conditions during the same calendar month, making them practical standalone alternatives or worthwhile additions to a longer regional itinerary.

Bangkok🇹🇭 Thailand364 km away

33°C26°C low

Ho Chi Minh City🇻🇳 Vietnam414 km away

33°C26°C low

Phnom Penh🇰🇭 Cambodia232 km away

34°C26°C low

Phu Quoc🇻🇳 Vietnam343 km away

29°C26°C low

Data Sources for Siem Reap

Siem Reap on Wikipedia Open-Meteo Climate API NOAA National Centers UK Met Office WMO GeoNames

Climate normals represent 30-year averages (1991-2020). Individual years may vary.