# Aviation Weather Density Altitude

> Aviation Weather Density Altitude is a paid API for AI agents from aviation-weather.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-29).

Returns density altitude, pressure altitude, and temperature data for an airport using live weather, quantifying the performance penalty for aircraft and drones.

## Facts

- Endpoint: GET https://aviation-weather.x402tookit.com/density-altitude?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/aviation-weather-density-altitude-1dc05024
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KsuKdUZLTVWSJ3H65FZRn

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability aviation-weather-density-altitude-1dc05024
```

Example prompt: What's the current density altitude at KDEN? I want to know how much of a performance hit my aircraft will take before I attempt a departure today.

## When to prefer this

Choose this endpoint when you need a computed density altitude value (not just raw METAR data) along with a plain-language performance verdict, especially for high-elevation or high-temperature airports where density altitude is a safety-critical concern. It is preferable over raw weather endpoints when you need the ISA deviation, pressure altitude, and a ready-made assessment of whether conditions are safe for aircraft or drone operations — without performing the calculation yourself.

## Known failure modes

- Invalid or unknown ICAO code returns an error or null fields
- Live weather data unavailable for remote airports may result in degraded=true with partial results
- Stale METAR data indicated by high ageMinutes value
- Missing altimeter or temperature readings prevent accurate density altitude calculation
- Network timeout or payment failure returns no data

## How this service works

Density altitude at an airport from live temperature and pressure: performance penalty for aircraft and drones.

## Output

Returns the computed density altitude in feet, pressure altitude in feet, current temperature and ISA standard temperature, altimeter setting, field elevation, a human-readable summary, a performance verdict (e.g. normal/high/very high), degraded-data flags, data source URL and age in minutes, and configurable thresholds for high and very-high density altitude warnings.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "icao"
     ],
     "properties": {
      "icao": {
       "type": "string",
       "description": "4-letter ICAO airport code"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "icao": {
       "type": [
        "null",
        "string"
       ]
      },
      "tempC": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "isaTempC": {
       "type": [
        "null",
        "number"
       ]
      },
      "observed": {
       "type": [
        "null",
        "string"
       ]
      },
      "sourceUrl": {
       "type": [
        "null",
        "string"
       ]
      },
      "ageMinutes": {
       "type": [
        "null",
        "number"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "thresholds": {
       "type": [
        "null",
        "object"
       ],
       "properties": {
        "highFt": {
         "type": [
          "null",
          "number"
         ]
        },
        "veryHighFt": {
         "type": [
          "null",
          "number"
         ]
        }
       }
      },
      "altimeterHpa": {
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/aviation-weather-density-altitude-1dc05024/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from aviation-weather.x402tookit.com](https://www.zero.xyz/host/aviation-weather.x402tookit.com/llms.txt)