Weather in Siem Reap in October

A hard month. October is a hard month in Siem Reap, and worth planning around. You should expect rain on 18 days of the month, which is more days wet than dry.

October ranks 5 of 12 in Siem Reap: past the worst of the year but short of December, which is the month to book if the dates are open.

Rain on 18 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Natural fibres and a second shirt for the day. At 84% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 23 days top 30 °C, making the heat continuous rather than occasional. Across the twenty years measured, the hottest October day reached 36.3 °C and the coldest night fell to 17.9 °C, and the wettest single day dropped 66 mm — roughly 48% of the month's rain in one day.

October is moderately variable: 25 mm in the driest year against 457 mm in the wettest, around an average of 138 mm. Roughly two Octobers in three land near that average, and the third does something else entirely.

Wind is light at 4.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, high enough to notice on the warm days without dominating them.

How October sits in the year

Temperatures hold steady either side: 30.4 °C in September, 31 here, 31.7 in November. Nothing about the timing within the month matters much. Rain is the thing that moves: November brings 10 days less of it, so pushing the dates later buys drier weather.

Daylight in October

Siem Reap sits close enough to the equator that daylight barely moves all year — 11.9 hours in October, against a range of just 1.6 hours across the whole calendar. Sunrise and sunset land at roughly the same time whenever you come.

An inland climate

Despite being inland, the year stays fairly even: 16.1 °C between the year's warmest afternoons and coldest nights.

How busy it gets

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

October in Siem Reap versus nearby

If Siem Reap is one option among several, the nearby comparison is worth making. Ubon Ratchathani is a better bet in October — within a degree on temperature, 6 days less rain. Nakhon Ratchasima is a better bet in October — within a degree on temperature, 2 days less rain.

So: October is a compromise. December is 28 points better and is what Siem Reap is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Siem Reap

See all twelve months in Siem Reap, or where else to go in October.