The Observatory provides new service on "Hot Weather Special Advisory"

To raise public awareness on the impact of hot weather, the Hong Kong Observatory (HKO) enhances its hot weather related services by introducing the "Hot Weather Special Advisory" (Figure 1) this summer to remind members of the public to remain vigilant under hot weather. Under such situations as high temperature, high humidity and light winds while the weather conditions remain below the level for issuing Very Hot Weather Warning, people may still be exposed to the risk of heat stroke if they do not take appropriate precautions. In view of this, the Observatory will issue the "Hot Weather Special Advisory" through the mobile app "MyObservatory" and the HKO website when such weather conditions are expected. The advisory serves to remind the public as early as possible to avoid being affected by hot weather, especially for those engaging in outdoor work or activities. They should pay attention to their health conditions, drink enough water and take appropriate protective measures against sunshine.

To monitor hot weather conditions, the HKO adopts a trial "Hong Kong Heat Index" (http://www.weather.gov.hk/wxinfo/ts/index_hkhi_e.htm) (Figure 2). This index reflects the combined effect of temperature, humidity, wind speed and solar radiation. In issuing the "Hot Weather Special Advisory" and the Very Hot Weather Warning, the HKO will monitor the atmospheric environment, consider the weather conditions at different places of Hong Kong and also make reference to this trial "Hong Kong Heat Index".

Figure 1 Hot Weather Special Advisory on HKO website

Figure 2 Time Series of Hong Kong Heat Index