Siem Reap climate
Siem Reap (Cambodia) has a tropical savanna (dry winter) climate (Köppen Aw). The average temperature over the year is 28 °C82 °F, and about 1,261 mm50 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Siem Reap climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 3492 | 2169 | 2781 | 120.5 |
| Feb | 3696 | 2373 | 2985 | 160.6 |
| Mar | 3697 | 2577 | 3187 | 461.8 |
| Apr | 3696 | 2678 | 3187 | 752.9 |
| May | 3493 | 2578 | 3085 | 1405.5 |
| Jun | 3289 | 2576 | 2883 | 1686.6 |
| Jul | 3087 | 2475 | 2781 | 1977.8 |
| Aug | 3087 | 2475 | 2781 | 1957.7 |
| Sep | 3086 | 2475 | 2781 | 2319.1 |
| Oct | 3187 | 2374 | 2781 | 1385.4 |
| Nov | 3188 | 2271 | 2780 | 371.5 |
| Dec | 3290 | 2068 | 2679 | 70.3 |
| Year | 3697 | 2068 | 2882 | 1,26150 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 57% | 43% | 5.0 | 11:25 |
| Feb | 53% | 39% | 5.3 | 11:41 |
| Mar | 57% | 61% | 5.4 | 12:01 |
| Apr | 64% | 70% | 5.8 | 12:25 |
| May | 75% | 83% | 5.7 | 12:44 |
| Jun | 82% | 86% | 5.4 | 12:54 |
| Jul | 85% | 88% | 5.2 | 12:50 |
| Aug | 86% | 90% | 5.0 | 12:34 |
| Sep | 87% | 90% | 4.8 | 12:11 |
| Oct | 84% | 75% | 4.8 | 11:49 |
| Nov | 78% | 60% | 4.8 | 11:29 |
| Dec | 65% | 52% | 4.8 | 11:20 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Siem Reap is like
The warmest month is April, with an average high of 36 °C96 °F and a low of 26 °C78 °F. The coldest is December, when highs average 32 °C90 °F and lows 20 °C68 °F. Seasonal differences are small — just 4.6 °C8.3 °F between the warmest and the coolest month.
It is wet, with about 1,261 mm50 in of precipitation per year. The wettest three-month stretch is July–September, which brings 49% of the annual total. Months with less than 20 mm0.8 in on average: December–February. The wettest month is September (231 mm9.1 in), the driest is December (7 mm0.3 in).
Relative humidity ranges from 53% in February to 87% in September. The clearest skies (lowest average cloud amount, 39%) are typical of February. Average wind speed near the ground ranges from 5 km/h (3 mph) in October to 7 km/h (4 mph) in August. Daylight lasts from about 11.3 hours in December to 12.9 hours in June.
Best time to visit Siem Reap
Based on these averages, the most comfortable months for sightseeing and outdoor activities are November and December: average highs of 31 °C88 °F to 32 °C90 °F with 7 mm0.3 in to 37 mm1.5 in of precipitation per month.
The most challenging month is September, which is hot, with average highs of 30 °C86 °F, very wet (231 mm9.1 in) and humid (87% relative humidity).
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Siem Reap
- Wetter months (May–October) — highs 3086 to 34 °C93 °F, lows 2374 to 25 °C78 °F, about 178 mm7.0 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water and an umbrella or light rain jacket.
- Drier months (November–April) — highs 3188 to 36 °C97 °F, lows 2068 to 26 °C78 °F, about 32 mm1.3 in of precipitation a month. Pack very light, breathable clothing, a sun hat and plenty of water.
How Siem Reap compares
Compared with Phnom Penh, about 231 km to the southeast, Siem Reap has practically the same average temperature and receives a similar amount of precipitation. The difference is largest in January (0.6 °C1 °F cooler).
Of the 4 places in Cambodia covered by World Climates, Siem Reap is the 2nd warmest by annual mean temperature and the 3rd wettest by annual precipitation. See all of them on the Cambodia climate page.
Places in other countries with the most similar temperature and rainfall pattern: Khlong Luang (Thailand, Aw), Bangkok (Thailand, Aw) and Kanchanaburi (Thailand, Aw).
Nearby places
- Battambang 77 km · 27 °C81 °F · 1,821 mm72 in
- Phnom Penh 231 km · 28 °C83 °F · 1,242 mm49 in
- Ubon Ratchathani 234 km · 27 °C81 °F · 1,523 mm60 in
- Kabin Buri 241 km · 27 °C81 °F · 1,533 mm60 in
- Nakhon Ratchasima 261 km · 27 °C80 °F · 1,220 mm48 in
- Si Maha Phot 262 km · 27 °C81 °F · 1,546 mm61 in
- Takeo 282 km · 28 °C82 °F · 1,287 mm51 in
- Rayong 292 km · 28 °C82 °F · 2,064 mm81 in
Frequently asked questions
What is the warmest month in Siem Reap?
April is the warmest month in Siem Reap, with an average high of 36 °C (96 °F) and an average low of 26 °C (78 °F).
What is the coldest month in Siem Reap?
December is the coldest month, with an average high of 32 °C (90 °F) and an average low of 20 °C (68 °F).
When does it rain the most in Siem Reap?
September is the wettest month with about 231 mm (9.1 in) of precipitation; December is the driest with about 7 mm (0.3 in).
What is the best time to visit Siem Reap?
Judging by long-term averages, the most comfortable months are November and December.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.