Current Weather Readings (HKO)

Source

Hong Kong Observatory (HKO)

Department URL: https://www.hko.gov.hk/
API Endpoint: https://data.weather.gov.hk/weatherAPI/opendata/weather.php?dataType=rhrread&lang=en
API Docs: https://www.hko.gov.hk/en/abouthko/opendata_intro.htm

Format

JSON Updated every ~10 minutes. No API key. CORS-enabled.

~10 min

Update Interval

Free

No Auth Required

~50

Weather Stations

Schema / Fields

Field	Path	Type	Example	Description
`temperature.data[].value`	root	float	`28.4`	Temperature (°C) at station
`temperature.data[].station`	root	string	`"HKO"`	Station code
`humidity.data[].value`	root	integer	`82`	Relative humidity (%)
`rainfall.data[].main`	root	string	`"Sha Tin"`	District rainfall zone
`rainfall.data[].amount`	root	float	`2.4`	Rainfall (mm) in past hour
`uvindex.data[].value`	root	integer	`3`	UV Index level
`updateTime`	root	string	`"2024-01-15T08:30:00+08:00"`	Last update timestamp
`warningMessage`	root	array	`["Amber Rainstorm Warning"]`	Active weather warnings

Example API Call

curl "https://data.weather.gov.hk/weatherAPI/opendata/weather.php?dataType=rhrread&lang=en" \
  | jq '{temp: .temperature.data[0], humidity: .humidity.data[0], warnings: .warningMessage}'

Example Response

{
  "rainfall": {
    "data": [
      {"unit": "mm", "main": "Hong Kong Observatory", "amount": 0.0, "place": "HKO"},
      {"unit": "mm", "main": "Sha Tin", "amount": 2.4, "place": "SHA TIN"}
    ]
  },
  "temperature": {
    "data": [
      {"unit": "C", "value": 28.4, "place": "Hong Kong Observatory", "station": "HKO"},
      {"unit": "C", "value": 27.8, "place": "King's Park", "station": "KP"}
    ],
    "recordTime": "2024-01-15T08:30:00+08:00"
  },
  "humidity": {
    "data": [{"unit": "percent", "value": 82, "place": "Hong Kong Observatory"}]
  },
  "uvindex": {
    "data": [{"unit": ".", "value": 3, "desc": "Moderate", "message": ""}]
  },
  "warningMessage": [],
  "updateTime": "2024-01-15T08:30:00+08:00"
}

Used By

Model	How
ABM Theory	Weather state modifies agent foot traffic probability — rain/heat suppress outdoor movement
LLM-Powered Agents	Real-time weather context fed to agent prompt as situational modifier

Notes / Gotchas

warningMessage array is empty on clear days — parse defensively
Temperature at “HKO” station (Tsim Sha Tsui) is the reference; urban heat island makes Sheung Wan ~1-2°C warmer in summer
UV Index correlates with outdoor dining willingness — UV 7+ (Very High) reduces outdoor seating occupancy
API is free but rate limiting applies: poll no more frequently than every 5 minutes per IP