The Community Weather Observing Scheme (CWOS) is an initiative of the Community Weather Information Network (Co-WIN) jointly established by the Hong Kong Observatory (HKO), the Hong Kong Polytechnic University (PolyU) and the Chinese University of Hong Kong (CUHK). Through offering various online platforms for everyone to upload weather photos and observation reports to share with others, we hope to encourage members of the public to carry out first-hand weather observations so as to broaden their knowledge on weather and climate.

Photos and images uploaded by users should meet the following criteria:

-       They should be users’ own work;

-       Their theme should be related to weather, including clouds, optical phenomena, weather phenomena and impacts of severe weather;

-       The date, time and place of the photos and images should be specified. We welcome photos taken outside Hong Kong; 

-       While minor processing of photos and images (such as brightness, contrast and saturation) is acceptable, they must genuinely reflect the actual weather situation.


Apart from this website, please also join the CWOS Facebook Group and download our smartphone app iCWeatherOS.

Under inclement weather, please beware of your personal safety and avoid taking photos outdoors. Please also pay attention to the weather information from the Observatory.


User Categories:


Basic User

Anyone with a valid email address may register on this website to become a Basic User. A Basic User can upload weather photos and observation reports on this website, and can view his/her own submissions in ‘My Album’


Advanced User

Based on the level of participation on our website and the quality of uploaded weather photos, a Basic User may be invited to become an Advanced User. Latest photos uploaded by Advanced Users will be shown on the front page of this website.


Taking part as Co-WIN member schools and organisations:


If members of Co-WIN would like to participate as a school / organisation so as to display all the weather photos and observation reports from the school / organisation within a single album, please apply by following these steps:


1. Teachers, students and members of the school / organisation should first register to become Basic Users on this website;


2. The person-in-charge or representative of the school / organisation should send the name of the school / organisation and the list of email addresses of these accounts to This email address is being protected from spambots. You need JavaScript enabled to view it.;


3. After the application is approved, the users may choose to upload weather photos and observation reports to the exclusive album of the school / organisation on the ‘Upload’ page. These users will also be automatically upgraded as ‘Advanced Users’;


4. By accessing Album Setting under 'User Menu', the person-in-charge may set the default location of the school / organisation album, and add or remove users under this album.


Browser requirements and configuration


This website is best viewed with Google Chrome (version 30 or above), Mozilla Firefox (version 4 or above), Microsoft Internet Explorer (version 11), Safari (version 5 or above) or Opera (version 22 or above). If you are using older versions of these browsers, you are recommended to update your browsers to the latest versions. In addition, Javascript has to be enabled on your browser to make full use of functions on this website.


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