Hong Kong Observatory Open Data HKO Open Data Portal

Overview

The Hong Kong Observatory (HKO) Open Data portal is the official open data initiative of the Hong Kong Observatory, a government department established in 1883. Through its open data program, HKO releases weather, climate, seismic, and tidal datasets in machine-readable formats free of charge for both commercial and non-commercial use, via the Government Open Data Portal (DATA.GOV.HK) and the Common Spatial Data Infrastructure (CSDI) portal.

History and Background

The Hong Kong Observatory was established on 2 March 1883 by Governor Sir George Bowen, with William Doberck as its first director. Originally known as the Royal Observatory, Hong Kong (a designation granted by King George V in 1912), the institution reverted to its current name following Hong Kong's handover to China in 1997. The Observatory has released weather data in machine-readable format since 2012 and continues to expand its open data offerings annually. As of 2025, HKO provides more than 48 datasets on the Government Open Data Portal, covering weather observations, forecasts, earthquake data, tidal information, and radiation levels. In June 2025, HKO released four additional datasets as part of its ongoing commitment to open data.

Collections and Data Offerings

The HKO Open Data portal provides datasets through a documented Application Programming Interface (API), enabling machine-to-machine data retrieval. Key data categories include real-time weather conditions (temperature, wind, humidity, pressure), nine-day weather forecasts, weather warnings and advisories, UV index readings, earthquake notifications, tidal data, solar radiation, and experimental smart lamppost sensor readings. All datasets adhere to international open data standards and are provided in standard formats such as JSON.

Access and Usage

All data is freely accessible without registration via the HKO website and the DATA.GOV.HK portal. An Open Data API with full technical documentation is available for developers. HKO publishes annual Open Data Plans outlining datasets to be released over the following three years, allowing developers and researchers to plan for future data integration. The Observatory's headquarters in Tsim Sha Tsui has been accredited by the World Meteorological Organization (WMO) as a Centennial Observing Station, reflecting over 140 years of continuous surface weather observations.