Hong Kong’s Labour Department will introduce two measures to make its workplace heat-warning system more sensitive from August 28, 2026, allowing higher-level warnings to be activated earlier during extreme heat and automatically raised when temperatures reach 35°C or above in multiple districts.
Under the first measure, the monitoring threshold for higher-level workplace heat warnings will be lowered while the Observatory’s Special Weather Tip on Extreme Heat is in force. This is intended to allow higher-level warnings to be issued earlier.
Under the second, if measured temperatures reach 35°C or above in multiple areas across Hong Kong, the warning level will automatically rise by one grade. Star Headline reported that conditions meeting the existing yellow-warning threshold would therefore be raised to red, while conditions already meeting the red-warning threshold would be raised to black.
Reports differ over whether the Observatory’s extreme-heat tip will itself automatically trigger a yellow workplace heat warning. Star Headline said it would, while Ming Pao described the measure as lowering the threshold for higher-level warnings. The specific effect of the tip therefore remains unclear from the reports.
The Labour Department said the changes would not create extra work for employers or employees. It reminded both sides to continue monitoring workplace heat warnings and their levels, and to make suitable work arrangements.
The department also encouraged employers to assess heat-stress risks according to the nature and location of the work and the specific working environment, then take preventive measures based on the assessment.
The department said it would continue reviewing how the system operates, including whether to add monitoring data such as wet-bulb globe temperature as an indicator. The system had issued only the lowest, yellow-level warning in the more than three years before the changes were announced, including during a recent period of high temperatures, prompting public discussion about whether warnings had been upgraded sufficiently.