Siem Reap weather in May

In May, Siem Reap sees average daytime highs of 34°C and overnight lows near 27°C, with 148 mm of rain across 21.4 wet days and about 12.6 hours of daylight. It is the 3rd-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 34°C through the month. The sky is clear or mostly clear about 10% of the time in May, and the air most often feels miserable.

Daylight stretches from about 12 h 30 min at the start of May to 12 h 42 min by month's end. Set against the rest of the year, May is Siem Reap's 8th-clearest and 10th-windiest month. For the whole year in context, see Siem Reap's year-round climate.

Daytime high
34°
3rd warmest
Overnight low
27°
12th coldest
Rainfall
148 mm
21.4 wet days
Daylight
12 h 36 min
5:42 AM – 6:19 PM
Cloud cover
78%
8th clearest
Wind
7 km/h
10th windiest
Solar energy
5.77 kWh/m²
Travel score
2.2
out of 10

Siem Reap is capital of the same named Cambodian province.

Founded
~802 CE

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 34°C through the month.

A typical May day in Siem Reap reaches about 34°C in the afternoon and slips back to 27°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 31°C and 37°C. Set against its neighbours, May runs about 1°C cooler than April and on par with June.

25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13427
23427
33427
43427
53427
63427
73427
83427
93427
103427
113427
123427
133427
143427
153427
163427
173427
183427
193427
203427
213427
223427
233327
243327
253327
263327
273327
283327
293327
303327
313327

How May really feels in Siem Reap

Once humidity and wind are folded in, May averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
31
31 feel dangerously hot (≥ 39°C)
Days feeling ≤ C
0
wind chill below the day's low

The story in May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Siem Reap weather by month

How May compares with the rest of the year at a glance. May is the 3rd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°91.911.35.5
Feb33° / 24°132.611.64.5
Mar34° / 26°527.811.93.2
Apr35° / 27°9413.512.32.5
May34° / 27°14821.412.62.2
Jun33° / 27°13220.712.82.4
Jul32° / 27°13522.112.72.6
Aug32° / 26°16224.412.42.4
Sep31° / 26°24425.912.12.5
Oct31° / 25°22423.311.73.1
Nov31° / 24°628.811.44.7
Dec30° / 23°162.911.25.7

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 10% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 11% of May, with mostly cloudy or overcast conditions the remaining 80%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13664
23565
33466
43268
53268
63070
72872
82872
92674
102476
112377
122278
132080
141981
151882
161783
171783
181684
191585
201585
211585
221486
231486
241486
251486
261486
271486
281387
291288
301288
311288

Chance of precipitation in May

Any precipitation

Siem Reap gets around 148 mm of rain over 21.4 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 69% and peaks near 77% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
154
255
356
457
558
659
761
862
963
1065
1166
1267
1369
1470
1571
1672
1773
1874
1974
2075
2175
2276
2376
2476
2576
2676
2777
2876
2976
3076
3176

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels miserable — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the miserable band about 90% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Oppressive (%)Miserable (%)
12080
21981
31783
41684
51585
61486
71387
81288
91189
101189
111090
121090
131090
141090
15991
16991
17991
18991
19892
20892
21892
22793
23793
24793
25793
26793
27694
28694
29694
30694
31793

Wind in May

Winds average 7 km/h in May.

Across May, daily wind ranges from about 7 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
318calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 30 min at the start of May to 12 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 12 minutes over May. Sunrise moves from 5:48 AM to 5:40 AM, and sunset from 6:16 PM to 6:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.55:486:16
212.55:476:16
312.55:476:16
412.55:466:16
512.55:466:17
612.55:466:17
712.55:456:17
812.55:456:17
912.65:446:18
1012.65:446:18
1112.65:446:18
1212.65:436:18
1312.65:436:18
1412.65:436:19
1512.65:436:19
1612.65:426:19
1712.65:426:20
1812.65:426:20
1912.65:426:20
2012.65:416:20
2112.75:416:21
2212.75:416:21
2312.75:416:21
2412.75:416:22
2512.75:416:22
2612.75:416:22
2712.75:406:22
2812.75:406:23
2912.75:406:23
3012.75:406:23
3112.75:406:24

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.77 kWh/m².

For context, solar energy here swings from a low near 4.62 kWh/m² to a high of 6.16 kWh/m² in April across the year — May's 5.77 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.0Intense
26.0Intense
36.0Intense
46.0Intense
56.0Bright
66.0Bright
75.9Bright
85.9Bright
95.9Bright
105.9Bright
115.8Bright
125.8Bright
135.8Bright
145.8Bright
155.7Bright
165.7Bright
175.7Bright
185.7Bright
195.7Bright
205.7Bright
215.6Bright
225.6Bright
235.6Bright
245.6Bright
255.6Bright
265.6Bright
275.6Bright
285.6Bright
295.6Bright
305.6Bright
315.6Bright
Planning a trip in May

Hazard calendar for Siem Reap

In seasonPeak

In May, Siem Reap sits inside its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.

Siem Reap sits in the Pacific typhoon belt; the season peaks July–October.

Siem Reap's rainy season runs May–October, when most of the year's rain falls.

Pacific typhoon
Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit Siem Reap?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

2.2
Sightseeing
12th-best month of the year
4.3
Beach & pool
9th-best month of the year

May is a weaker month for outdoor sightseeing in Siem Reap.

What to pack for Siem Reap in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Siem Reap sees daytime highs around 34°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection. About 21 days see rain.

light clothesrain gearsun protection

UV index in Siem Reap in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Siem Reap peaks around August 16 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 22 at about 8 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highAug 16UV 14Nov 22UV 8
UV index (midday)Level
Jan10Very high
Feb10Very high
Mar12Extreme
Apr12Extreme
May11Extreme
Jun12Extreme
Jul13Extreme
Aug14Extreme
Sep12Extreme
Oct11Extreme
Nov8Very high
Dec8Very high

Air quality in Siem Reap in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Siem Reap is worst in February — around 40 µg/m³ PM2.5 (poor), about 2.9× the cleanest month (November, 14 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateFeb 2240 µg/m³Nov 2214 µg/m³
PM2.5 (µg/m³)Level
Jan29Moderate
Feb40Poor
Mar40Poor
Apr37Poor
May19Moderate
Jun15Moderate
Jul16Moderate
Aug15Moderate
Sep15Moderate
Oct17Moderate
Nov14Moderate
Dec14Moderate
Location & terrain

Where is Siem Reap?

Siem Reap sits at 13.4°N, 103.9°E, 18 m above sea level, in Cambodia. The nearest listed city is Yeang, 34 km away.

YeangPhum Ânlŭng VĭlBattambangPhumĭ TnaôtPursatSamraongSisophonAnlong Veaeng

Topography around Siem Reap

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Siem Reap.

Within 3 km, the terrain around Siem Reap has only modest variations in elevation — a maximum elevation change of 28 m around an average of 17 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 123 m; within 80 km, significant variations in elevation — a maximum elevation change of 484 m.

The land around Siem Reap is covered by artificial surfaces (60%) and trees (24%) within 3 km, cropland (45%) and trees (30%) within 16 km, and cropland (48%) and trees (30%) within 80 km.

3 km
28 m
16 km
123 m
80 km
484 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
May weather nearby: Yeang 34 km · Phum Ânlŭng Vĭl 74 km · Battambang 77 km · Phumĭ Tnaôt 89 km · Pursat 92 km · Samraong 98 km · Sisophon 99 km · Anlong Veaeng 100 km

Cambodia travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type A / C / G
230 V · 50 Hz
Prices
≈ 34% of US
price level, 2025
GDP per capita
$2,872
2025
Happiness
4.5 / 10
World Happiness, 2025
Safe drinking water
30%
of population, 2024
Homicide rate
1.8
per 100k, 2011
Road deaths
19.6
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
Very low
EF EPI 390
Religion
Buddhist 97%Muslim 2%other 1%Christian 0%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Siem Reap (13.3618°, 103.8606°, elevation 18 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).