Siem Reap air quality

Latest reading · 5 Nov 2026, 21:00–22:00 Cambodia time

• Siem Reap: PM2.5 4.7 µg/m³ · Good · US AQI ≈ 26

Good for outdoor activities. The air is clean. A great time to be outside.

The latest PM2.5 and air quality index (AQI) from monitors in Siem Reap, updated every hour.

• Is the air safe right now, and what should you do
• The cleanest hours for a run along the riverside
• How bad the dry season (November–April) gets, by month and by day
• A map of air quality across Cambodia

Telegram: @hazekh · a morning update and alerts when the air turns unhealthy

Data & method

PM2.5 comes from low-cost AirGradient monitors in Siem Reap, published hourly by OpenAQ, with the US EPA correction for this sensor type. The city’s value is the median across its monitoring sites, so one faulty sensor can’t move it. Levels and AQI follow the US EPA’s PM2.5 breakpoints (2024 revision). Times are Cambodia time (UTC+7).

About HazeKH

HazeKH is an independent project. It isn’t part of any government agency, OpenAQ or AirGradient. Each monitor’s owner shares its readings publicly on OpenAQ.

Contact: @chenmengky