Siem Reap is a monsoon-rhythm destination — the year splits into a lush green season and a dry golden one. The numbers below are real — monthly weather computed from the ERA5 climate archive for Siem Reap's exact coordinates — so this page answers the question most guides dodge: which months are actually worth your leave days?
The short answer: aim for January, February, December, skip July if you can, and read the packing notes before you book. Post-monsoon months are the secret: everything is green, waterfalls are full, and crowds haven't returned.
| Month | Day / Night | Rain | Travel score |
|---|---|---|---|
| January | 31.3° / 21.7°C | 2mm | 100 · best |
| February | 32.9° / 23.6°C | 26mm | 97 |
| March | 34.3° / 25.4°C | 55mm | 85 |
| April | 37.4° / 27.7°C | 28mm | 70 |
| May | 34° / 26.6°C | 225mm | 66 |
| June | 33.2° / 26°C | 163mm | 78 |
| July | 30.9° / 24.9°C | 323mm | 60 · toughest |
| August | 32.5° / 25.2°C | 197mm | 75 |
| September | 31.3° / 24.8°C | 317mm | 60 |
| October | 30.9° / 23.9°C | 289mm | 64 |
| November | 31.5° / 23.3°C | 97mm | 88 |
| December | 30° / 21.3°C | 29mm | 96 |
Pack a compact umbrella or poncho, quick-dry layers, and waterproof covers for electronics. Footwear that survives wet streets earns its space twice over.
Give Siem Reap 3–5 focused days. Mornings for the headline sights (crowds arrive after 10), afternoons for neighbourhoods, evenings for food. The free RoamWise planner turns this into a full day-by-day itinerary with budgets in your currency — and shows the crowd calendar for Siem Reap next to 195+ other destinations.
🥷 Plan Siem Reap free — crowd calendar, budget & AI itinerary →January, February, December score highest on our weather-comfort index — daytime around 31.3°C with manageable rainfall. Post-monsoon months are the secret: everything is green, waterfalls are full, and crowds haven't returned.
July is the toughest window (30.9°C days, ~323mm rain). Peak monsoon weeks can disrupt transport and close trails — build slack into plans.
Pack a compact umbrella or poncho, quick-dry layers, and waterproof covers for electronics.
Most travelers are happy with 3–5 focused days; add 2 more if you want day trips around Siem Reap. The free RoamWise planner builds the day-by-day plan.