# METAR & NWS Weather Station Observations API (`bigdavidson/metar-nws-weather-station-observations`) Actor

Raw METAR strings and decoded NWS ASOS hourly observations by ICAO station or lat/lon: temp, wind, ceiling, visibility, flight category. The official station data Kalshi weather markets settle on. No login, no API keys. From $0.50 per 1,000 records.

- **URL**: https://apify.com/bigdavidson/metar-nws-weather-station-observations.md
- **Developed by:** [Jack Sheward](https://apify.com/bigdavidson) (community)
- **Categories:** Other, Travel, Developer tools
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, NaN bookmarks
- **User rating**: No ratings yet

## Pricing

from $0.50 / 1,000 observation records

This Actor is paid per event and usage. You are charged both the fixed price for specific events and for Apify platform usage.

Learn more: https://docs.apify.com/platform/actors/running/actors-in-store#pay-per-event

## What's an Apify Actor?

Actors are a software tools running on the Apify platform, for all kinds of web data extraction and automation use cases.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.
Actors are written with capital "A".

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.
The best way to integrate Actors is as follows.

In JavaScript/TypeScript projects, use official [JavaScript/TypeScript client](https://docs.apify.com/api/client/js.md):

```bash
npm install apify-client
```

In Python projects, use official [Python client library](https://docs.apify.com/api/client/python.md):

```bash
pip install apify-client
```

In shell scripts, use [Apify CLI](https://docs.apify.com/cli/docs.md):

````bash
# MacOS / Linux
curl -fsSL https://apify.com/install-cli.sh | bash
# Windows
irm https://apify.com/install-cli.ps1 | iex
```bash

In AI frameworks, you might use the [Apify MCP server](https://docs.apify.com/platform/integrations/mcp.md).

If your project is in a different language, use the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).


# README

<!-- Console SEO fields (set manually, separate from this README):
SEO title (40-50 ch):  METAR & NWS Weather Station Observations API
SEO description (140-156 ch): Pull raw METAR strings and NWS ASOS hourly observations by ICAO station or lat/lon. Decoded temp, wind, ceiling, visibility, flight category. JSON/CSV.
-->

## METAR & NWS Weather Station Observations API

Pull **raw METAR strings** and **hourly ASOS/NWS weather station observations** for any ICAO station (KORD, KJFK, KLAX…) or any lat/lon point — decoded into clean JSON with temperature, dewpoint, wind, ceiling, visibility, and **flight category** (VFR/MVFR/IFR/LIFR). Up to **30 days of hourly history** per station.

This is the observation data that aviation tools, weather dashboards, and **prediction markets (Kalshi/Polymarket weather contracts)** actually resolve on — straight from official sources (aviationweather.gov + the ASOS archive), not scraped weather websites that break.

### What you get

One record per station per observation:

| Field | Example |
|---|---|
| `station_id` | `KORD` |
| `station_name` | `Chicago O'Hare Intl` |
| `lat`, `lon` | `41.97`, `-87.9` |
| `utc_time` | `2026-06-09T18:52:00Z` |
| `temp_f`, `dewpoint_f` | `78.8`, `60.1` |
| `wind_dir`, `wind_speed_kt` | `240`, `12` |
| `ceiling_ft` | `5500` |
| `visibility_sm` | `10` |
| `flight_category` | `VFR` |
| `metar_raw` | `KORD 091852Z 24012KT 10SM BKN055 26/16 A3002 …` |
| `source` | `aviationweather.gov` |

Export as JSON, CSV, or Excel directly from the dataset.

### Input

```json
{
  "stationIds": ["KORD", "KMDW"],
  "latLon": [{ "lat": 40.78, "lon": -73.97 }],
  "hoursBack": 24
}
````

- `stationIds` — ICAO codes. US ASOS stations fully supported; international stations supported up to 72h lookback.
- `latLon` — optional points, resolved to the nearest official observation station automatically.
- `hoursBack` — 1 to 720. Up to 72h is served from aviationweather.gov (freshest); longer lookbacks from the ASOS archive.
- `fields` — optional list to slim the output (e.g. just `["temp_f"]`).

### Pricing

Pay per observation record — no subscription. A 24h pull for one station is ~24 records.

### Why this instead of scraping a weather website?

- **Primary sources.** aviationweather.gov + ASOS archive — the same observations NWS publishes, with raw METAR included for auditability.
- **No scrape fragility.** Public JSON/CSV APIs, not HTML scraping that breaks on redesigns.
- **Resolution-grade.** If you settle weather derivatives or prediction-market positions, you need the observation of record, not a weather app's interpolation.

### FAQ

#### Which stations are supported?

Any ICAO station reporting METAR. Deep history (beyond 72h) covers US ASOS stations (K-prefix).

#### How fresh is the data?

aviationweather.gov observations typically appear within minutes of the station report.

#### Can I get the exact raw METAR string?

Yes — every record carries `metar_raw` exactly as published.

#### How do I get daily max/min temperature for Kalshi weather markets?

Pull `hoursBack: 24` for the station (e.g. `KNYC` markets resolve on Central Park-area stations) and take the max/min of `temp_f` — or watch this developer's other actors for a dedicated Kalshi weather-markets feed.

#### Does it work for a lat/lon with no airport nearby?

Yes — `latLon` resolves through the official NWS station registry to the nearest observing station.

### Use with AI agents (MCP)

Connect your agent to the Apify MCP server (mcp.apify.com) and it can call this actor as a tool: ask for "the latest METAR observations at KNYC" or "hourly temperatures at KMDW for the last 24 hours" and the agent fills the input schema (stationIds, hoursBack) itself. Useful as a ground-truth weather lookup for trading agents, aviation assistants, and research pipelines.

### More prediction-market data actors

- [Kalshi Weather Markets Data (KXHIGH & KXLOW)](https://apify.com/bigdavidson/kalshi-weather-markets) - live bracket prices and settlement history for the markets these observations resolve.
- [Prediction Market Resolution Evidence Checker](https://apify.com/bigdavidson/prediction-market-resolution-evidence) - paste a Kalshi weather market URL, get the live observation that resolves it, graded.

# Actor input Schema

## `stationIds` (type: `array`):

Weather station ICAO codes, e.g. KORD, KJFK, KLAX. US ASOS stations have full support; international ICAO stations are served for lookbacks up to 72 hours.

## `latLon` (type: `array`):

Lat/lon points to resolve to the nearest observation station, e.g. \[{"lat": 41.97, "lon": -87.9}]. Each resolves via the NWS station registry and is added to the station list.

## `hoursBack` (type: `integer`):

How many hours of hourly observations to pull per station. Up to 72h is served from aviationweather.gov (freshest, sub-hour latency); 73-720h is served from the Iowa State Mesonet ASOS archive.

## `fields` (type: `array`):

Subset of output fields to keep (station\_id and utc\_time always included). Leave empty for all fields.

## Actor input object example

```json
{
  "stationIds": [
    "KORD"
  ],
  "latLon": [],
  "hoursBack": 24,
  "fields": []
}
```

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "stationIds": [
        "KORD"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("bigdavidson/metar-nws-weather-station-observations").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "stationIds": ["KORD"] }

# Run the Actor and wait for it to finish
run = client.actor("bigdavidson/metar-nws-weather-station-observations").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print("💾 Check your data here: https://console.apify.com/storage/datasets/" + run["defaultDatasetId"])
for item in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "stationIds": [
    "KORD"
  ]
}' |
apify call bigdavidson/metar-nws-weather-station-observations --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "command": "npx",
            "args": [
                "mcp-remote",
                "https://mcp.apify.com/?tools=bigdavidson/metar-nws-weather-station-observations",
                "--header",
                "Authorization: Bearer <YOUR_API_TOKEN>"
            ]
        }
    }
}

```

## OpenAPI specification

```json
{
    "openapi": "3.0.1",
    "info": {
        "title": "METAR & NWS Weather Station Observations API",
        "description": "Raw METAR strings and decoded NWS ASOS hourly observations by ICAO station or lat/lon: temp, wind, ceiling, visibility, flight category. The official station data Kalshi weather markets settle on. No login, no API keys. From $0.50 per 1,000 records.",
        "version": "0.1",
        "x-build-id": "uV9cLzlhpv8uAbaDx"
    },
    "servers": [
        {
            "url": "https://api.apify.com/v2"
        }
    ],
    "paths": {
        "/acts/bigdavidson~metar-nws-weather-station-observations/run-sync-get-dataset-items": {
            "post": {
                "operationId": "run-sync-get-dataset-items-bigdavidson-metar-nws-weather-station-observations",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor, waits for its completion, and returns Actor's dataset items in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK"
                    }
                }
            }
        },
        "/acts/bigdavidson~metar-nws-weather-station-observations/runs": {
            "post": {
                "operationId": "runs-sync-bigdavidson-metar-nws-weather-station-observations",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor and returns information about the initiated run in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK",
                        "content": {
                            "application/json": {
                                "schema": {
                                    "$ref": "#/components/schemas/runsResponseSchema"
                                }
                            }
                        }
                    }
                }
            }
        },
        "/acts/bigdavidson~metar-nws-weather-station-observations/run-sync": {
            "post": {
                "operationId": "run-sync-bigdavidson-metar-nws-weather-station-observations",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK"
                    }
                }
            }
        }
    },
    "components": {
        "schemas": {
            "inputSchema": {
                "type": "object",
                "properties": {
                    "stationIds": {
                        "title": "Station IDs (ICAO)",
                        "type": "array",
                        "description": "Weather station ICAO codes, e.g. KORD, KJFK, KLAX. US ASOS stations have full support; international ICAO stations are served for lookbacks up to 72 hours.",
                        "default": [
                            "KORD"
                        ],
                        "items": {
                            "type": "string"
                        }
                    },
                    "latLon": {
                        "title": "Coordinates (optional)",
                        "type": "array",
                        "description": "Lat/lon points to resolve to the nearest observation station, e.g. [{\"lat\": 41.97, \"lon\": -87.9}]. Each resolves via the NWS station registry and is added to the station list.",
                        "default": []
                    },
                    "hoursBack": {
                        "title": "Hours of history",
                        "minimum": 1,
                        "maximum": 720,
                        "type": "integer",
                        "description": "How many hours of hourly observations to pull per station. Up to 72h is served from aviationweather.gov (freshest, sub-hour latency); 73-720h is served from the Iowa State Mesonet ASOS archive.",
                        "default": 24
                    },
                    "fields": {
                        "title": "Fields filter (optional)",
                        "type": "array",
                        "description": "Subset of output fields to keep (station_id and utc_time always included). Leave empty for all fields.",
                        "default": [],
                        "items": {
                            "type": "string"
                        }
                    }
                }
            },
            "runsResponseSchema": {
                "type": "object",
                "properties": {
                    "data": {
                        "type": "object",
                        "properties": {
                            "id": {
                                "type": "string"
                            },
                            "actId": {
                                "type": "string"
                            },
                            "userId": {
                                "type": "string"
                            },
                            "startedAt": {
                                "type": "string",
                                "format": "date-time",
                                "example": "2025-01-08T00:00:00.000Z"
                            },
                            "finishedAt": {
                                "type": "string",
                                "format": "date-time",
                                "example": "2025-01-08T00:00:00.000Z"
                            },
                            "status": {
                                "type": "string",
                                "example": "READY"
                            },
                            "meta": {
                                "type": "object",
                                "properties": {
                                    "origin": {
                                        "type": "string",
                                        "example": "API"
                                    },
                                    "userAgent": {
                                        "type": "string"
                                    }
                                }
                            },
                            "stats": {
                                "type": "object",
                                "properties": {
                                    "inputBodyLen": {
                                        "type": "integer",
                                        "example": 2000
                                    },
                                    "rebootCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "restartCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "resurrectCount": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "computeUnits": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            },
                            "options": {
                                "type": "object",
                                "properties": {
                                    "build": {
                                        "type": "string",
                                        "example": "latest"
                                    },
                                    "timeoutSecs": {
                                        "type": "integer",
                                        "example": 300
                                    },
                                    "memoryMbytes": {
                                        "type": "integer",
                                        "example": 1024
                                    },
                                    "diskMbytes": {
                                        "type": "integer",
                                        "example": 2048
                                    }
                                }
                            },
                            "buildId": {
                                "type": "string"
                            },
                            "defaultKeyValueStoreId": {
                                "type": "string"
                            },
                            "defaultDatasetId": {
                                "type": "string"
                            },
                            "defaultRequestQueueId": {
                                "type": "string"
                            },
                            "buildNumber": {
                                "type": "string",
                                "example": "1.0.0"
                            },
                            "containerUrl": {
                                "type": "string"
                            },
                            "usage": {
                                "type": "object",
                                "properties": {
                                    "ACTOR_COMPUTE_UNITS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_WRITES": {
                                        "type": "integer",
                                        "example": 1
                                    },
                                    "KEY_VALUE_STORE_LISTS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_INTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_EXTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_RESIDENTIAL_TRANSFER_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_SERPS": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            },
                            "usageTotalUsd": {
                                "type": "number",
                                "example": 0.00005
                            },
                            "usageUsd": {
                                "type": "object",
                                "properties": {
                                    "ACTOR_COMPUTE_UNITS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATASET_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "KEY_VALUE_STORE_WRITES": {
                                        "type": "number",
                                        "example": 0.00005
                                    },
                                    "KEY_VALUE_STORE_LISTS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_READS": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "REQUEST_QUEUE_WRITES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_INTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "DATA_TRANSFER_EXTERNAL_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_RESIDENTIAL_TRANSFER_GBYTES": {
                                        "type": "integer",
                                        "example": 0
                                    },
                                    "PROXY_SERPS": {
                                        "type": "integer",
                                        "example": 0
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}
```
