Cambodia Phnom Penh Weather in May — Climate Guide
May in Phnom Penh is moderate
May is moderate for Phnom Penh.
May is the transition month — monsoon onset + value pricing returns. Rainfall jumps from April's 75mm to 145mm (rainy days 6 → 13), with afternoon thunderstorms 14:00-17:00 the new pattern. Mornings remain mostly clear and humid. The big positive: heat eases from April's 36°C / 97°F peak back to 34°C / 93°F. Pricing drops 30-40% from January-February peak — boutique hotels $40-90/night, Raffles + Rosewood + Sofitel luxury $250-500. Visak Bochea (Buddha's Birthday, May full moon — varies year-by-year) brings temple ceremonies at all Phnom Penh wats with morning monk processions. Royal Plowing Ceremony (varies, traditional Khmer agricultural ritual in front of Royal Palace) is a unique cultural-photography opportunity. Mornings outdoor + afternoons indoor pattern is the right schedule. Yangon and Phnom Penh share similar monsoon timing but Phnom Penh has less extreme rainfall.
Travel score
Monsoon onset + Buddha's Birthday + value pricing returns
May Weather at a Glance
May averages 93°F / 34°C highs and 77°F / 25°C lows with 13 rainy days and 145mm of rain. Humidity 75%. UV 11. Sunshine 7.5 hours. Daily afternoon thunderstorms 14:00-17:00; mornings often clear.
May Travel Advice
Schedule outdoor activities for mornings (07:00-13:00). Afternoon thunderstorms 14:00-17:00 = museum, spa, cafe, cooking class time. Pre-book Royal Palace + Killing Fields for early morning to beat storms. Visak Bochea wat ceremonies are pre-dawn (05:00-06:30) — beautiful cultural photography. Late May (May 16-31) is the year's best value window — 50-60% of high-season pricing.
Flying In from Overseas
Monsoon onset + low season = year's lowest tourist arrivals from Western markets. Direct connection via Bangkok or Singapore $400-800. European pre-summer shoulder.
May Pricing Trends
30-40% off peak: boutique $40-90/night, Raffles $250-500, Rosewood $230-450. Flights $400-800 from East Asia. Year's best value window starts May 16.
Phnom Penh May Weather Stats
Avg High
34°C
Avg Low
25°C
Rainy Days
13
145mm total
Sunshine
7.5h
Daily avg
Humidity
75%
humid
UV Index
11
Extreme
Wind
8 km/h
Gusts 22
Sea Temp
29°C
Mekong River swim not recommended (rising muddy water)
Crowds
Moderate
At attractions
May Sunrise & Sunset
Air Quality
PM2.5
35 μg/m³
PM10
60 μg/m³
Status
moderate
Feels-Like Temperature & Wind
Feels like
Daytime
38°C
Nighttime
27°C
Humidity and wind affect how the actual temperature feels.
Wind
8 km/h
Max gust 22 km/h
Activities Recommended for May
May Travel Pros & Cons
Pros
- Heat eases from April peak
- 30-40% off peak hotel pricing
- Lush green landscapes start
- Visak Bochea + Royal Plowing Ceremony cultural depth
Cons
- Daily afternoon thunderstorms
- Some Mekong cruises cancel during heavy rain
- Photography limited to mornings
May Events & Festivals
- Monsoon officially starts mid-month
- Visak Bochea (Buddha's Birthday, May full moon) — temple ceremonies at all wats
- Royal Plowing Ceremony (varies, in front of Royal Palace) — ancient Khmer agricultural ritual
- Low-season pricing begins — 30-40% off peak
Phnom Penh in May — Full Picture
May is the transition month — monsoon onset + value pricing returns. Rainfall jumps from April's 75mm to 145mm (rainy days 6 → 13), with afternoon thunderstorms 14:00-17:00 the new pattern. Mornings remain mostly clear and humid. The big positive: heat eases from April's 36°C / 97°F peak back to 34°C / 93°F. Pricing drops 30-40% from January-February peak — boutique hotels $40-90/night, Raffles + Rosewood + Sofitel luxury $250-500. Visak Bochea (Buddha's Birthday, May full moon — varies year-by-year) brings temple ceremonies at all Phnom Penh wats with morning monk processions. Royal Plowing Ceremony (varies, traditional Khmer agricultural ritual in front of Royal Palace) is a unique cultural-photography opportunity. Mornings outdoor + afternoons indoor pattern is the right schedule. Yangon and Phnom Penh share similar monsoon timing but Phnom Penh has less extreme rainfall.
What to Wear & What to Pack
Monsoon onset — afternoon thunderstorms 14:00-17:00 become the daily pattern. Quick-dry clothes + packable rain shell + waterproof phone case essential. Days 34°C / 93°F + nights 25°C / 77°F. Light layer for AC restaurants.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
Current35°C
25°C
7.3/mo
Summer (Jun·Jul·Aug)
32.3°C
25°C
17.7/mo
Autumn (Sep·Oct·Nov)
31°C
23.7°C
15/mo
Winter (Dec·Jan·Feb)
31.3°C
22°C
1.7/mo
Phnom Penh Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| January (Best) | 31° | 22° | 1d·10mm | 9h | 65% | 9 | Very busy | Peak |
| February (Best) | 33° | 23° | 1d·10mm | 9.5h | 60% | 10 | Very busy | Peak |
| 35° | 24° | 3d·35mm | 9h | 65% | 11 | Busy | Shoulder | |
| 36° | 26° | 6d·75mm | 8.5h | 70% | 12 | Busy | Peak | |
| 34° | 25° | 13d·145mm | 7.5h | 75% | 11 | Moderate | Shoulder | |
| 33° | 25° | 16d·200mm | 6.5h | 80% | 10 | Quiet | Low season | |
| 32° | 25° | 18d·220mm | 6h | 82% | 10 | Moderate | Shoulder | |
| 32° | 25° | 19d·220mm | 6h | 82% | 10 | Moderate | Shoulder | |
| 32° | 25° | 19d·250mm | 6h | 82% | 9 | Quiet | Low season | |
| 31° | 24° | 17d·240mm | 7h | 80% | 9 | Moderate | Low season | |
| November (Best) | 30° | 22° | 9d·100mm | 8h | 70% | 9 | Very busy | Peak |
| December (Best) | 30° | 21° | 3d·25mm | 9h | 65% | 9 | Busy | Peak |
View Other Months
Phnom Penh May Hotel Picks
Frequently Asked Questions
Is May a good time to visit Phnom Penh?
Phnom Penh in May is moderate. Tourist crowds are moderate and flight/hotel prices are shoulder.
What's the average temperature in Phnom Penh in May?
Phnom Penh May averages a high of 34°C and a low of 25°C.
Does it rain much in Phnom Penh in May?
Phnom Penh May averages 145mm of rainfall over about 13 rainy days.
What should I wear in Phnom Penh in May?
Monsoon onset — afternoon thunderstorms 14:00-17:00 become the daily pattern. Quick-dry clothes + packable rain shell + waterproof phone case essential. Days 34°C / 93°F + nights 25°C / 77°F. Light layer for AC restaurants.
What time are sunrise and sunset in Phnom Penh in May?
Phnom Penh May sunrise is 05:40 and sunset is 18:20, with 12h 40min of daylight.
What's the air quality like in Phnom Penh in May?
Phnom Penh May air quality (AQI) averages 70, rated Moderate. PM2.5 averages 35μg/m³.
What activities are recommended in Phnom Penh in May?
In May, Phnom Penh is great for Royal Palace early morning, Killing Fields early morning, Visak Bochea wat ceremonies.
Is May peak season in Phnom Penh?
Phnom Penh May crowds are moderate and prices are shoulder. You can travel relatively comfortably without long queues.
Best Months to Visit Phnom Penh
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.