THW comfort index API

Computes the Temperature-Humidity-Wind index used by personal weather stations: the heat index reduced by a Davis-style wind-cooling term. Answers 'What is the THW index at 35C, 60% RH, 15 km/h wind?', 'How much does wind offset this heat?'.

Price$0.04per request

MethodPOST

Route/v1/climate/thw-index

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

thwtemperature-humidity-windfeels-likedavisweather-stationthermal-comfortheatwind

API URLhttps://x402.hexl.dev/v1/climate/thw-index

Integration docs

Example request

{
  "tempC": 35,
  "relativeHumidity": 60,
  "windSpeedKmh": 15
}

Example response

{
  "thwC": 39.5,
  "thwF": 103.1,
  "heatIndexC": 45.05,
  "windSpeedKmh": 15,
  "windCoolingF": 9.99,
  "interpretation": "THW 39.5°C — heat index reduced by 10°F of wind cooling.",
  "formula": "THW = HeatIndex(°F) − 1.072·wind(mph), per Davis weather-station convention"
}

Input schema

{
  "type": "object",
  "required": [
    "tempC",
    "relativeHumidity",
    "windSpeedKmh"
  ],
  "properties": {
    "tempC": {
      "type": "number",
      "description": "Air temperature in Celsius",
      "examples": [
        35
      ]
    },
    "relativeHumidity": {
      "type": "number",
      "description": "Relative humidity in percent (0-100)",
      "examples": [
        60
      ]
    },
    "windSpeedKmh": {
      "type": "number",
      "description": "Wind speed in km/h",
      "examples": [
        15
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}