Siem Reap in December
In December, Siem Reap averages 31°C (88°F) during the day and 21°C (70°F) at night, with only about 3 rainy days.
High seasonConditions are warm and beach-friendly. Skies are generally dry and clear.
December 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.).
How December compares to the rest of the year in Siem Reap
December is one of the coolest months in Siem Reap (12th of 12) and one of the driest months (10th of 12). Daytime temperature runs 2°C below the annual average (33°C). December runs roughly the same as November (31°C) and warms a further 1°C into January (32°C).
December sunrise & sunset in Siem Reap
Times shown for Siem Reap local time (Asia/Phnom_Penh), calculated for the 15th of December. They shift by a few minutes day to day across the month.
Photography light in Siem Reap — December
Golden-hour and blue-hour windows for the 15th of December, in Siem Reap's local time. Use these for soft warm light (golden) or cool architectural twilight (blue).
📅 When to book — Siem Reap in December
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 December's tier (High season) and Siem Reap's popularity.
Crowds & pricing — December in Siem Reap
This is a busy month in Siem Reap — not the absolute peak, but tourist numbers are clearly elevated. You'll feel it at headline attractions on weekends and in the historic centre, though side streets and lesser-known sights stay manageable. Prices are above off-season but not at their summit. A good week for first-time visitors who want everything open without the worst of the crush.
Why this tier: comfortable tourism weather Christmas / New Year travel surge
Sun & mosquito risk — December in Siem Reap
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
| Month | Avg high | Avg low | Rainfall | Rain days | Snow 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 December weather
🌍 See the full ranked list of climate twins for Siem Reap in December →
Frequently asked questions
How hot is Siem Reap in December?
In December, Siem Reap averages a high of 31°C (88°F) and a low of 21°C (70°F) — generally hot.
Does it rain a lot in Siem Reap in December?
December is generally dry in Siem Reap, with about 3 rainy days on average.
Is December a good time to visit Siem Reap?
December is hot and mostly dry. 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 December?
Pack lightweight, breathable clothing, sunglasses and sunscreen. See the full December packing list for Siem Reap for a complete, climate-based checklist.
Check the live 10-day forecast and sunrise/sunset.