Siem Reap is rarely comfortable to be outside at midday. It comes closest in late December, and even then it is too hot. For sun, aim for December to January.
When to go five ratings · thirty-six ten-day sections · click a cell to read it
The sun season here runs from December to January, with a second spell in mid and late February. It peaks in early January, at 71. The weakest stretch is from mid April to June, when it drops to 18, mostly because it is too hot. The clearest skies come in February, when the sky is typically 37% covered at midday (partly cloudy).
Being outside is not what Siem Reap is for: the Easy outdoors rating tops out at 31, mostly because it is too hot.
Walking is not what Siem Reap is for: the Active outdoors rating tops out at 11, mostly because it is too warm.
The year, measured
The average temperature in Siem Reap over the whole year is 28°C. April is the hottest month, with highs of about 34°C; January is the coldest, with lows of about 23°C. Siem Reap has no sharply defined rainy season: the chance of rain on a given day runs from 5% in January, the driest month, to 19% in July, the wettest. Winds in Siem Reap are highest in August, averaging 2.0 m/s (7 km/h), and lightest in January, at 1.4 m/s (5 km/h). The prevailing wind is from the S. The clearest skies in Siem Reap come in February, when the sky is typically 33% covered; September is the cloudiest month, at 63%.
Month by month Siem Reap climate by month: average temperatures year round · click a month to read it
| Month | High | Low | Feels like | Chance of rain | Cloud | Wind | Being outside | Sun | Walking |
|---|---|---|---|---|---|---|---|---|---|
| January | 30°C | 23°C | 30°C | 5% | 38% | 1.4 m/s | 24 | 67 | 7 |
| February | 31°C | 24°C | 32°C | 5% | 33% | 1.6 m/s | 13 | 57 | 2 |
| March | 33°C | 26°C | 35°C | 6% | 40% | 1.5 m/s | 5 | 34 | 0 |
| April | 34°C | 27°C | 36°C | 8% | 44% | 1.5 m/s | 4 | 25 | 0 |
| May | 33°C | 27°C | 36°C | 12% | 53% | 1.5 m/s | 5 | 20 | 0 |
| June | 32°C | 27°C | 35°C | 14% | 55% | 1.7 m/s | 6 | 21 | 1 |
| July | 31°C | 26°C | 34°C | 19% | 60% | 1.9 m/s | 7 | 32 | 0 |
| August | 32°C | 26°C | 35°C | 12% | 59% | 2.0 m/s | 4 | 33 | 0 |
| September | 30°C | 26°C | 34°C | 15% | 63% | 1.7 m/s | 8 | 36 | 1 |
| October | 30°C | 25°C | 33°C | 12% | 57% | 1.5 m/s | 11 | 38 | 3 |
| November | 30°C | 24°C | 33°C | 12% | 49% | 1.4 m/s | 14 | 47 | 3 |
| December | 29°C | 23°C | 30°C | 5% | 42% | 1.5 m/s | 28 | 61 | 9 |
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Siem Reap weather by season
Year round, Siem Reap has days of about 29°C at their warmest in December, its coolest month, and 34°C in April, its warmest; the coolest hours of the day run from 23°C to 27°C through the year, and the average temperature over the year is 28°C around the clock. Rain is most likely around July and least likely around January. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Siem Reap weather in winterDecember to February
Winter in Siem Reap has typical daily highs of about 30°C and lows of about 23°C, with a 5% chance of rain on a given day.
Siem Reap weather in springMarch to May
Spring in Siem Reap has typical daily highs of about 33°C and lows of about 26°C, with a 9% chance of rain on a given day.
Siem Reap weather in summerJune to August
Summer in Siem Reap has typical daily highs of about 32°C and lows of about 26°C, with a 15% chance of rain on a given day.
Siem Reap weather in autumnSeptember to November
Autumn in Siem Reap has typical daily highs of about 30°C and lows of about 25°C, with a 13% chance of rain on a given day.
When is the rainy season in Siem Reap?
Siem Reap has no sharply defined rainy season: the chance of rain on a given day runs from 5% in January, the driest month, to 19% in July, the wettest.
What time of year is Siem Reap windiest?
Winds in Siem Reap are highest in August, averaging 2.0 m/s (7 km/h), and lightest in January, at 1.4 m/s (5 km/h). The prevailing wind is from the S.
What is the average temperature in Siem Reap year round?
The average temperature in Siem Reap over the whole year is 28°C. April is the hottest month, with highs of about 34°C; January is the coldest, with lows of about 23°C.
Where to go instead in late April, the weakest time here for being outside
How this is worked out
Every figure is a decade of weather-station observations blended into one typical year, in ten-day sections. The ratings, the chart and the feels-like column are read at midday local solar time. Being outside is the Easy outdoors rating, Sun is Sunbathing and Walking is Active outdoors, each out of 100: Good from 55, Ideal from 80. They describe what a time of year is usually like here, not a forecast. The dotted links open the map at that time of year; set its time of day to midday to see these numbers.