Climate averages 1991–2020
Siem Reap weather
by month.
See how the year changes. April has the highest average daily maximum; January has the lowest average monthly rainfall.
Long-term climate patterns, not a forecast for a particular trip.
Across the year Siem Reap averages a daytime high of 31.7°C and a nighttime low of 24.3°C, with about 1,289 mm of rain on roughly 175 days. April is the warmest month (average high 34.2°C) and October the coolest (30.0°C). September is the wettest month with 244 mm; January is the driest with 9.0 mm.
The annual picture
A year in Siem Reap
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 | 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
Nearby cities
- BattambangCambodia · 77 kmHigh 32.5°C · Low 24.1°C · 1,052 mm rain a year
- Paoy PaetCambodia · 144 kmHigh 31.6°C · Low 23.6°C · 1,214 mm rain a year
- Kampong ChhnangCambodia · 151 kmHigh 32.2°C · Low 24.4°C · 1,343 mm rain a year
- ChanthaburiThailand · 208 kmHigh 29.8°C · Low 24.2°C · 2,333 mm rain a year
- Phnom PenhCambodia · 231 kmHigh 32.2°C · Low 24.4°C · 1,374 mm rain a year
- Ubon RatchathaniThailand · 234 kmHigh 31.3°C · Low 23.0°C · 1,441 mm rain a year
- DangkaoCambodia · 234 kmHigh 32.2°C · Low 24.4°C · 1,374 mm rain a year
- Kabin BuriThailand · 241 kmHigh 31.2°C · Low 23.0°C · 1,499 mm rain a year
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 limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC+7, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 13.40°, 103.90° (6 km from the city centre), adjusted down by 0.1°C for the difference between the city's elevation (18 m) and the cell's (10 m). Rain comes from the 0.25° cell at 13.25°, 103.75°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.