If you’re planning a trip to Siem Reap during Christmas, you’ll get to soak up warm, comfortable weather while wandering through temples and local neighborhoods. Daytime temperatures usually hit around 80–86°F (27–30°C), and mornings or evenings cool off just enough to make sightseeing pretty pleasant.
December feels a lot nicer than the sticky, hot months. It’s honestly one of the best times to be outside.
You’ll probably notice that rainfall drops off dramatically compared to the wet season. Most days, the sky stays clear or just a bit cloudy, and there’s enough sunshine to fill both your mornings and afternoons.
That mix of warmth, low humidity, and very little rain draws plenty of visitors. December is a favorite month for good reason.
Typical December Weather in Siem Reap
In December, Siem Reap gives you warm days, cooler nights, and mostly dry skies. Sightseeing and outdoor activities feel comfortable, and both rainfall and humidity stay pretty low compared to other times of year.
Temperature Trends Near Christmas
Most afternoons in December reach 30–32°C (86–90°F), so it’s warm but not like the brutal hot season. Nights drop down to about 20–22°C (68–72°F), which is a nice break after a day in the sun.
The temperature doesn’t really swing wildly from day to day. You’ll want lightweight clothes during the day and maybe a light jacket or shirt for the evening.
Compared to April or May, December is a relief. The air feels drier, and the heat isn’t as intense, so you can spend more time outside without getting wiped out.
Precipitation Patterns
December falls in the dry season here. Rainfall averages 10–20 mm for the month, and you’ll probably only see 2–3 wet days.
Showers, if they happen, usually pass quickly and don’t mess up your plans.
With this little rain, you’re looking at mostly clear skies and loads of sunshine. Average daily sunshine clocks in at 7–8 hours, so you’ve got plenty of daylight for temples or markets.
Chances of rain stay under 10% most days. You don’t need heavy rain gear, but tossing a small umbrella or poncho in your bag isn’t a bad idea.
Humidity and Dew Point
In December, relative humidity averages around 60–65%. That’s much lower than the wet season, where it can spike past 80%. The air feels a lot more comfortable, especially when the sun’s out.
The dew point usually sits between 18–21°C (64–70°F). At that range, things feel warm but not sticky—one reason December is such a pleasant time to visit.
Mornings often feel crisp, and afternoons stay warm without that heavy, damp feeling you get during the monsoon. Outdoor activities feel easier and less exhausting.
Average Temperature and Daily Ranges
Around Christmas, Siem Reap feels warm in the daytime and cools off at night, with little risk of crazy heat. The daily temperature range is noticeable, but it stays much more comfortable than the hotter months.
Daytime and Nighttime Averages
In late December, the average high temperature is about 85°F (29°C). That’s warm, but it won’t leave you drenched in sweat, so temple-hopping and market visits are much easier.
At night, the average low temperature drops to around 71°F (22°C). It’s cool enough to sleep comfortably, and you probably won’t even need strong air conditioning.
April can see highs up to 95°F (35°C), so December is a welcome change. The smaller gap between day and night temps also helps cut down on that muggy feeling.
| Time of Day | Average Temp |
|---|---|
| Afternoon High | 85°F / 29°C |
| Evening Avg | 77°F / 25°C |
| Night Low | 71°F / 22°C |
Average Hourly Temperature Variations
December’s hourly temperature pattern is pretty steady. Mornings start off mild, afternoons peak in the mid-80s °F, and by late evening, things cool back down to the low 70s °F.
The warmest hours usually run from 1:00 PM to 3:00 PM, when the sun’s strongest. The coolest hours are before sunrise, often around 5:00 to 6:00 AM.
December skies are clearer than in the wet season, so you get more direct sun in the day and slightly cooler nights. This makes outdoor activities comfortable through most of the day.
Rainfall and Precipitation During Christmas
Rainfall in December is minimal in Siem Reap, and the dry season shapes the weather. You’re likely to see clear skies almost every day, with only the odd light shower.
Average Monthly Rainfall in December
December stands out as one of the driest months in Siem Reap. Rainfall totals usually stay between 7 mm and 50 mm, depending on where you are in Cambodia. In Siem Reap, it’s typically closer to the lower end.
During the wet season, rainfall can be several hundred millimeters, but by December, the monsoon has moved on. Dry air and stable conditions take over.
If it rains, it’s usually just a quick burst. Long stretches of rain are rare, and many days pass without a single drop.
Humidity drops too, making it even more comfortable for sightseeing and exploring Angkor Wat.
Chance of Rainy Days
Late December barely sees any rain. Records show Siem Reap averages just 1–2 rainy days for the whole month. Most travelers get a completely dry trip.
When rain does show up, it’s light and short—no heavy storms to worry about. Flooding or travel delays from weather are almost unheard of at this time.
You probably won’t need to plan around rain. Packing a raincoat is optional, but most people don’t use it. The dry season keeps your holiday running smoothly.
Cloud Cover and Sunshine
December brings drier skies to Siem Reap, though you’ll still get some clouds now and then. Expect a mix of partly cloudy days and long stretches of sunshine—great for being outside.
Typical Cloud Cover in December
Clouds in December are lighter than during the monsoon, so you’ll see clearer skies most of the day. Sometimes clouds drift by, but they rarely turn into rain.
Most days swing between partly cloudy and mostly sunny. That makes it easier to plan trips to Angkor Wat or other temples without worrying about the weather.
Compared to September’s overcast skies, December is much brighter. Lower humidity also means less haze than earlier in the year.
Mornings often start clear, and a few clouds might build up in the afternoon, but they’re usually not thick enough to block the sun.
Sunshine Hours Around Christmas
December is one of the sunniest months in Siem Reap. On average, you’ll get about 8 to 9 hours of sunlight daily, more than during the wet season.
There’s enough daylight for full-day outings, and you won’t lose visibility early. The sun rises just after 6:00 a.m. and sets around 5:30 p.m., so you get steady daylight hours.
Heavy clouds in the rainy season cut sunlight, but December’s clear skies let more sun through. That’s perfect for outdoor markets, bike rides, or even a boat trip on Tonle Sap Lake.
If you like cooler sightseeing, mornings and late afternoons give you good light without the midday heat.
Wind and Comfort Levels
In December, Siem Reap’s weather feels a lot more comfortable than during the rainy months. Winds stay light, and humidity levels drop, making outdoor activities way more enjoyable.
Average Wind Speed in December
Winds in December are calm. Average speeds run between 5 to 8 mph (8 to 13 km/h), with only the occasional stiffer breeze. These light winds don’t mess with your plans.
Most of the time, gentle northeasterly winds blow through. That’s typical for Cambodia’s dry season. The breeze is steady but never strong enough to make walking or cycling tough.
If you’re planning to take a boat ride on Tonlé Sap Lake or wander around temple sites, the wind adds a bit of cooling without causing any problems. The calm air also means less dust than in the hotter months, when winds pick up.
Visitors usually find the wind in December just right—enough to keep things fresh, but never enough to be annoying.
Muggy Days and Comfort
December is one of the least humid months in Siem Reap. Average relative humidity falls to about 65–70%, much lower than the sticky rainy season.
You’ll notice fewer muggy days. Early mornings feel fresh, and evenings are great for walking or eating outside. Midday can still get warm, with highs near 86°F (30°C), but the drier air makes it easier to handle.
Compared to May or September, when humidity often tops 80%, December is a clear winner. Sweat dries faster, so you cool off more quickly.
You’ll still want light clothes and plenty of water, but you won’t be battling the oppressive stickiness that hangs over Cambodia for much of the year. Sightseeing and long days at Angkor Wat are way more manageable.
Weather at Siem Reap International Airport
Around Christmas, Siem Reap International Airport sees warm but not extreme temperatures, low rainfall, and pleasant evenings. The dry season is in full swing, so flights and outdoor plans rarely get disrupted by weather.
Airport-Specific Temperature and Rainfall
In December, daily highs at the airport average 85°F (29°C), and nighttime lows dip to about 70°F (21°C). Days feel warm, but after sunset, the air cools off enough to make evenings comfortable.
Rain is rare now. The chance of a wet day drops from about 6% in early December to 3% by the end of the month. Monthly rainfall averages only 0.1–0.4 inches, which is about as low as it gets all year.
Humidity keeps dropping through the month, so it feels less muggy than during the wet season. With more clear skies, you’ll get plenty of sunshine and fewer weather-related delays at the airport.
| Measure | Typical December Value |
|---|---|
| High Temp | 85°F (29°C) |
| Low Temp | 70°F (21°C) |
| Rainfall | 0.1–0.4 in (3–10 mm) |
| Chance of Rain | 3–6% |
Travel Tips Based on Weather
Pack light clothing for the daytime, but don’t forget a light jacket for those cooler evenings. With less humidity, you’ll probably find it easier to walk around the terminal and the city, though it’s still a good idea to carry water.
You probably won’t need heavy rain gear since rain rarely shows up. Toss a small umbrella or poncho in your bag, just in case there’s a quick shower.
Flights usually run on time in December, since weather delays are pretty rare. Clear skies and lower rainfall help pilots see better for takeoff and landing.
If you’re planning to be outside after you arrive, grab some sunscreen and a hat. The sun’s strong, even in the dry season. Early mornings and late afternoons feel more comfortable for exploring, so maybe plan your outings then.
How December Compares to Other Months
December in Siem Reap brings dry skies, mild humidity, and cooler nights. It’s honestly one of the most comfortable times to visit. Compared to the hotter, wetter months, the weather feels more stable and predictable, which helps if you’re planning outdoor activities or temple visits.
Weather by Month Overview
Siem Reap’s weather falls into three main phases: the hot season, the rainy season, and the cooler dry season. December sits in the cooler dry season, with average highs around 30–32°C (86–90°F) and lows near 21–22°C (70–72°F). Rain barely makes an appearance, maybe just 1–2 days all month.
April gets brutally hot, often hitting 35–37°C (95–99°F) with barely any relief at night. From May to October, the monsoon rolls in with heavy rainfall, high humidity, and frequent storms. Those months can see 200–300 mm of rain, while December usually gets just 15–20 mm.
If you look at December next to January and February, the weather’s pretty similar. January tends to run a bit cooler, while February brings more sunshine and clear days. December really does land in the sweet spot for travel.
Seasonal Changes Leading Into Christmas
December rolls in and the wet season finally ends. By late November, the heavy rains let up, leaving everything looking greener but with way less rain each day.
You’ll find the ground dries out, and the skies clear up, which means getting around Angkor’s temples feels a lot easier.
Humidity drops in December, too—usually around 60–65%. That’s a big change from the muggy 80% you’d get back in September.
Nights actually feel cooler now, and you can actually enjoy being outside after dark, instead of just sweating through the evenings.
There’s more sunshine, with about 8–9 hours of daylight most days. You’ll probably notice more clear skies, making it perfect for exploring outdoors.
You get all the perks of good weather without the crazy heat or the big crowds that show up later in the year.