PSI (Air Quality)

Returns Singapore's air quality Pollutant Standards Index (PSI) readings from data.gov.sg.

GET /sg/psi

Parameters

Parameter	Required	Default	Description
dateTime	No	Latest	Specific date-time to query in YYYY-MM-DDTHH:mm:ss format
metric	No	psi_twenty_four_hourly	PSI metric to use (see below)

Available metrics

Metric	Description
psi_twenty_four_hourly	24-hour PSI (default)
psi_three_hourly	3-hour PSI
pm25_sub_index	PM2.5 sub-index
pm10_sub_index	PM10 sub-index
o3_sub_index	Ozone sub-index
so2_sub_index	Sulphur dioxide sub-index
co_sub_index	Carbon monoxide sub-index

Example

curl "https://api.uwuapps.org/sg/psi"

Response

{
  "success": true,
  "timestamp": "2025-01-15T10:00:00+08:00",
  "metric": "psi_twenty_four_hourly",
  "national": {
    "value": 45,
    "band": {
      "max": 50,
      "name": "Good",
      "cls": "good"
    }
  },
  "primaryPollutant": {
    "key": "pm25_sub_index",
    "name": "PM2.5",
    "value": 45
  },
  "regions": [
    {
      "region": "west",
      "value": 42,
      "band": { "name": "Good", "cls": "good" },
      "pm25": 42,
      "pm10": 30,
      "o3": 20,
      "so2": 5,
      "co": 3
    },
    { "region": "east", "value": 48, "band": { "name": "Good", "cls": "good" }, "pm25": 48, "pm10": 35, "o3": 22, "so2": 6, "co": 4 },
    { "region": "central", "value": 45, "band": { "name": "Good", "cls": "good" }, "pm25": 45, "pm10": 32, "o3": 21, "so2": 5, "co": 3 },
    { "region": "south", "value": 44, "band": { "name": "Good", "cls": "good" }, "pm25": 44, "pm10": 31, "o3": 20, "so2": 5, "co": 3 },
    { "region": "north", "value": 43, "band": { "name": "Good", "cls": "good" }, "pm25": 43, "pm10": 30, "o3": 19, "so2": 5, "co": 3 }
  ]
}

PSI bands

Range	Name	Class
0–50	Good	good
51–100	Moderate	moderate
101–200	Unhealthy	unhealthy
201–300	Very Unhealthy	very-unhealthy
301+	Hazardous	hazardous

Notes

• Returns the most recent reading if dateTime is not specified.

• Returns 404 if no readings are available for the requested time.

• Returns 502 if data.gov.sg is unreachable.