Window Close: AQI, PM2.5, Dust

Window Close tells you in one line whether it is safe to open your window right now.

It combines real-time PM10 and PM2.5 levels with yellow dust, ozone and Korea Meteorological Administration weather data. No need to interpret numbers - just look for "Open the window" or "Keep it closed".


■ Open or Close

Most apps stop at showing you numbers. Window Close weighs air quality against rain and wind, then tells you whether now is a good time to air out your home.


■ Real-Time Air Quality

- PM10, PM2.5, yellow dust, ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide
- Grading based on Korea Environment Corporation and WHO reference levels
- Official AirKorea monitoring station data
- Shows the nearest station and its distance


■ Forecast

Three-day PM10 forecast for today, tomorrow and the day after, plus hourly changes.


■ Weather

Temperature, feels-like, daily high and low, humidity, chance of rain, hourly and weekly forecast.


■ 7 Home Screen Widgets

PM10 widget, PM2.5 widget, weather widget, combined air quality and weather widget, and clock widgets in small and large sizes.
Adjust background transparency, text size and color so you can check everything without opening the app.


■ Alerts

Get notified at the times and on the days you choose, and whenever air quality gets worse.


■ Favorites

Save the places you check often - home, work, anywhere - and switch between them with one tap.


Covers all regions of South Korea - Korean, English and Japanese - last known data available offline

We collect no personal information. Location is used only to look up conditions for your area, and favorites and your recent location stay on your device.

We run only the minimum advertising needed to keep the app running, and we're deliberate about where and how often ads appear, with your experience in mind.


▶ Data Sources
Air quality: Korea Environment Corporation AirKorea (https://www.airkorea.or.kr)
Weather: Korea Meteorological Administration (https://data.kma.go.kr)

▶ Notice
This app does not represent any government agency. It is independently developed using public data Open APIs.
Readings may differ from actual measurements.

Recent changes:
- Fixed hourly forecasts not matching actual data
- Fixed previous location info showing after switching locations
- Fixed wrong region shown when location couldn't be found
- Fixed missed alerts and alerts for the wrong region
- Improved home screen widget refresh accuracy
- Recent info now shows even on slow connections