Siem Reap weather in December
December in Siem Reap: hot, dry, with clean air — one of the best months to visit.
#2 of 12 months in Siem Reap · #177 of 604 destinations to visit in December · comfort 79/100 (tier B)
Updated June 2026 · climate normals from ERA5 reanalysis
Siem Reap climate normals — December
| Daytime high | 30°C / 85°F | 🥵 hot |
|---|---|---|
| Nighttime low | 21°C / 70°F | |
| Feels like (high) | 33°C / 91°F | |
| Rainfall | 20 mm / 0.8 in | ☀️ dry |
| Rainy days | 4 days | |
| Humidity | 72% | 💧 humid |
| Dew point | 20°C / 67°F | |
| Sunshine | 9.9 h/day | |
| Daylight | 11.4 h | |
| Wind | 14 km/h / 8 mph | |
| Air quality (US AQI) | 38 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Siem Reap in December — FAQ
- Is December a good time to visit Siem Reap?
- December in Siem Reap: hot, dry, with clean air — one of the best months to visit. It ranks #2 of 12 months for Siem Reap on SeasonMap's comfort score (79/100).
- What is the weather like in Siem Reap in December?
- In December, Siem Reap averages a daily high of 29.6°C and a low of 21.1°C, with about 19.6 mm of rain over roughly 3.6 rainy days.
- What is the air quality in Siem Reap in December?
- Siem Reap has a mean US Air Quality Index of about 38 in December.