Climate averages 1991–2020
Siem Reap weather
in December.
A hot, fairly dry month: the joint 10th warmest and the 3rd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a hot month in Siem Reap: daytime highs average 30.1°C and nights cool to about 21.7°C. By daytime temperature it is the joint 10th warmest of the 12 months.
Expect about 16 mm of rain on roughly 3 days, which makes December a fairly dry month (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 21 min on an average December day.
The nearest other city in this atlas is Battambang (77 km away). In December its highs average 30.5°C, about as warm as Siem Reap, with 13 mm of rain.
Among the 8 cities listed in Cambodia, Siem Reap ranks joint 6th of 8 for the warmest December highs and 3rd of 8 for the driest December (rainfall, lowest first). The mean December high of those 8 cities is 30.3°C; Siem Reap is 0.2°C cooler than that mean.
From December to January, average highs rise by 1.2°C to 31.3°C, and monthly rainfall falls from 16 mm to 9.0 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Siem Reap climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 31.3°C21.9°C | 21.9°C | 9.0 | 1.9 | 11.411 h |
| February | 32.8°C23.5°C | 23.5°C | 13 | 2.6 | 11.712 h |
| March | 34.1°C25.4°C | 25.4°C | 52 | 7.8 | 12.012 h |
| April | 34.2°C26.1°C | 26.1°C | 94 | 13.4 | 12.412 h |
| May | 33.0°C26.1°C | 26.1°C | 148 | 21.4 | 12.713 h |
| June | 32.0°C25.7°C | 25.7°C | 131 | 20.7 | 12.913 h |
| July | 31.3°C25.3°C | 25.3°C | 135 | 22.0 | 12.813 h |
| August | 31.0°C25.1°C | 25.1°C | 162 | 24.3 | 12.613 h |
| September | 30.3°C24.5°C | 24.5°C | 244 | 25.9 | 12.212 h |
| October | 30.0°C23.8°C | 23.8°C | 224 | 23.2 | 11.812 h |
| November | 30.1°C22.8°C | 22.8°C | 62 | 8.8 | 11.512 h |
| December, selected | 30.1°C21.7°C | 21.7°C | 16 | 2.9 | 11.411 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Battambang in DecemberCambodia · 77 kmHigh 30.5°C · Low 21.5°C · 13 mm rain
- Paoy Paet in DecemberCambodia · 144 kmHigh 30.1°C · Low 21.0°C · 5.8 mm rain
- Kampong Chhnang in DecemberCambodia · 151 kmHigh 30.5°C · Low 22.4°C · 22 mm rain
- Chanthaburi in DecemberThailand · 208 kmHigh 30.0°C · Low 22.3°C · 16 mm rain
- Phnom Penh in DecemberCambodia · 231 kmHigh 30.5°C · Low 22.7°C · 27 mm rain
- Ubon Ratchathani in DecemberThailand · 234 kmHigh 29.4°C · Low 19.5°C · 6.3 mm rain
- Dangkao in DecemberCambodia · 234 kmHigh 30.5°C · Low 22.8°C · 27 mm rain
- Kabin Buri in DecemberThailand · 241 kmHigh 30.1°C · Low 20.4°C · 5.1 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Siem Reap) is explained once on the Siem Reap year overview and on the Sources, method and limits page.