According to the Hong Kong Observatory ordinance, classes will be cancelled under:
1) the Rainstorm Black Warning Signal; or
2) the local Storm Warning Signal No. 8 or above.
The classes will be cancelled 2 hours prior to the lectures when a signal is hoisted. Please check the update from the Hong Kong Observatory. 2 hours before the class to see whether your class will be cancelled.
For details, please visit the website of Hong Kong Observatory: www.hko.gov.hk/contente.htm