Yr alerts API

openapi: 3.0.3
info:
  title: Locationforecast alerts API
  description: Weather forecasts for any location on Earth up to nine days ahead, returning temperature, wind, precipitation, cloud cover, humidity, and more. Available in compact JSON, complete JSON with probabilistic percentiles, and legacy XML formats. Data is open under CC BY 4.0 and requires only a User-Agent header.
  version: '2.0'
  contact:
    name: Developer Support
    url: https://developer.yr.no/
    email: weatherapi-adm@met.no
  license:
    name: CC BY 4.0
    url: https://creativecommons.org/licenses/by/4.0/
  termsOfService: https://developer.yr.no/doc/TermsOfService/
servers:
- url: https://api.met.no/weatherapi/locationforecast/2.0
  description: MET Norway Locationforecast API
tags:
- name: alerts
  description: Weather alert endpoints
paths:
  /current:
    get:
      tags:
      - alerts
      operationId: getCurrentAlerts
      summary: Get active weather alerts
      description: Returns all currently active weather alerts and warnings. Supports filtering by event type, geographic domain, county, and coordinates.
      parameters:
      - $ref: '#/components/parameters/lang'
      - $ref: '#/components/parameters/event'
      - $ref: '#/components/parameters/geographicDomain'
      - $ref: '#/components/parameters/county'
      - $ref: '#/components/parameters/lat'
      - $ref: '#/components/parameters/lon'
      - $ref: '#/components/parameters/sort'
      - $ref: '#/components/parameters/cap'
      responses:
        '200':
          description: Active alerts
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AlertCollection'
            application/xml:
              schema:
                type: string
                description: CAP XML alert feed
            application/rss+xml:
              schema:
                type: string
                description: RSS feed of active alerts
        '204':
          description: No Content - no active alerts matching criteria
        '400':
          description: Bad Request
        '401':
          description: Unauthorized
        '403':
          description: Forbidden
        '404':
          description: Not Found
        '422':
          description: Unprocessable Entity
        '429':
          description: Too Many Requests
        '500':
          description: Internal Server Error
        '502':
          description: Bad Gateway
        '503':
          description: Service Unavailable
        '504':
          description: Gateway Timeout
  /all:
    get:
      tags:
      - alerts
      operationId: getAllAlerts
      summary: Get all alerts from the last 30 days
      description: Returns both active and inactive weather alerts from the last 30 days. Useful for reviewing recent alert history.
      parameters:
      - $ref: '#/components/parameters/lang'
      - $ref: '#/components/parameters/event'
      - $ref: '#/components/parameters/geographicDomain'
      - $ref: '#/components/parameters/county'
      - $ref: '#/components/parameters/lat'
      - $ref: '#/components/parameters/lon'
      - $ref: '#/components/parameters/sort'
      - $ref: '#/components/parameters/cap'
      responses:
        '200':
          description: All recent alerts
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AlertCollection'
            application/xml:
              schema:
                type: string
            application/rss+xml:
              schema:
                type: string
        '204':
          description: No Content
        '400':
          description: Bad Request
        '429':
          description: Too Many Requests
        '500':
          description: Internal Server Error
  /archive:
    get:
      tags:
      - alerts
      operationId: getArchivedAlerts
      summary: Get archived historical alerts
      description: Retrieve archived alerts by month or specific date. Historical data available from January 2019 onwards. Filter heavily to avoid timeouts on large result sets, especially for GeoJSON format.
      parameters:
      - $ref: '#/components/parameters/lang'
      - $ref: '#/components/parameters/event'
      - $ref: '#/components/parameters/geographicDomain'
      - $ref: '#/components/parameters/county'
      - name: period
        in: query
        required: false
        description: Archive period in YYYY-MM format
        schema:
          type: string
          pattern: ^\d{4}-\d{2}$
          example: 2024-01
      - name: date
        in: query
        required: false
        description: Specific archive date in YYYY-MM-DD format
        schema:
          type: string
          format: date
          example: '2024-01-15'
      - $ref: '#/components/parameters/sort'
      responses:
        '200':
          description: Archived alerts
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AlertCollection'
            application/xml:
              schema:
                type: string
            application/rss+xml:
              schema:
                type: string
        '400':
          description: Bad Request
        '429':
          description: Too Many Requests
        '500':
          description: Internal Server Error
  /test:
    get:
      tags:
      - alerts
      operationId: getTestAlerts
      summary: Get active test alerts
      description: Returns currently active test warning alerts for development and testing.
      parameters:
      - $ref: '#/components/parameters/lang'
      responses:
        '200':
          description: Test alerts
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AlertCollection'
            application/xml:
              schema:
                type: string
            application/rss+xml:
              schema:
                type: string
        '204':
          description: No Content
        '500':
          description: Internal Server Error
  /test_all:
    get:
      tags:
      - alerts
      operationId: getAllTestAlerts
      summary: Get all test alerts from the last 30 days
      description: Returns all test warning alerts from the last 30 days.
      parameters:
      - $ref: '#/components/parameters/lang'
      responses:
        '200':
          description: All test alerts
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AlertCollection'
            application/xml:
              schema:
                type: string
        '204':
          description: No Content
        '500':
          description: Internal Server Error
  /example:
    get:
      tags:
      - alerts
      operationId: getExampleAlerts
      summary: Get example alerts for development
      description: Returns sample alert messages that expire in 2034, intended for development and integration testing.
      parameters:
      - $ref: '#/components/parameters/lang'
      responses:
        '200':
          description: Example alerts
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AlertCollection'
            application/xml:
              schema:
                type: string
        '500':
          description: Internal Server Error
components:
  parameters:
    lat:
      name: lat
      in: query
      required: false
      description: Latitude for coordinate-based geographic search
      schema:
        type: number
        format: float
        example: 59.91
    event:
      name: event
      in: query
      required: false
      description: Filter by weather warning event type
      schema:
        type: string
        enum:
        - blowingSnow
        - forestFire
        - gale
        - ice
        - icing
        - lightning
        - polarLow
        - rain
        - rainFlood
        - snow
        - stormSurge
        - wind
        example: wind
    lon:
      name: lon
      in: query
      required: false
      description: Longitude for coordinate-based geographic search
      schema:
        type: number
        format: float
        example: 10.75
    county:
      name: county
      in: query
      required: false
      description: Two-digit Norwegian county number (land alerts only)
      schema:
        type: string
        pattern: ^\d{2}$
        example: '11'
    lang:
      name: lang
      in: query
      required: false
      description: Output language
      schema:
        type: string
        enum:
        - 'no'
        - en
        example: en
    geographicDomain:
      name: geographicDomain
      in: query
      required: false
      description: Filter by geographic domain
      schema:
        type: string
        enum:
        - land
        - marine
    cap:
      name: cap
      in: query
      required: false
      description: CAP identifier to retrieve a specific CAP XML message
      schema:
        type: string
    sort:
      name: sort
      in: query
      required: false
      description: Sort RSS result items by field
      schema:
        type: string
        enum:
        - area
        - event
        - incidentName
        - t_onset
        - t_published
        - type
  schemas:
    AlertCollection:
      title: Alert Collection
      type: object
      description: GeoJSON FeatureCollection of weather alert features. Each feature represents one alert with geographic and attribute data.
      properties:
        type:
          type: string
          enum:
          - FeatureCollection
        features:
          type: array
          items:
            $ref: '#/components/schemas/AlertFeature'
    AlertProperties:
      title: Alert Properties
      type: object
      description: Properties of a weather alert
      properties:
        id:
          type: string
          description: CAP message identifier
        title:
          type: string
          description: Alert title
        description:
          type: string
          description: Detailed alert description
        event:
          type: string
          description: Weather event type (e.g., wind, rain, snow)
        eventAwarenessName:
          type: string
          description: Human-readable event awareness name
        severity:
          type: string
          enum:
          - Extreme
          - Severe
          - Moderate
          - Minor
          description: Alert severity level
        certainty:
          type: string
          enum:
          - Observed
          - Likely
          - Possible
          - Unlikely
        awareness_level:
          type: string
          description: Color-coded awareness level (red, orange, yellow, green)
        onset:
          type: string
          format: date-time
          description: When the alert period begins
        expires:
          type: string
          format: date-time
          description: When the alert expires
        published:
          type: string
          format: date-time
          description: When the alert was published
        msgType:
          type: string
          enum:
          - Alert
          - Update
          - Cancel
          description: CAP message type
        county:
          type: array
          items:
            type: string
          description: Affected Norwegian county codes
        geographicDomain:
          type: string
          enum:
          - land
          - marine
        incidentName:
          type: string
          description: Named incident identifier (red alerts only)
        resources:
          type: array
          items:
            type: object
            properties:
              description:
                type: string
              mimeType:
                type: string
              uri:
                type: string
                format: uri
    AlertFeature:
      title: Alert Feature
      type: object
      description: GeoJSON Feature representing a single weather alert
      properties:
        type:
          type: string
          enum:
          - Feature
        geometry:
          type: object
          description: Geographic area covered by the alert (Polygon or MultiPolygon)
        properties:
          $ref: '#/components/schemas/AlertProperties'
externalDocs:
  description: Official documentation
  url: https://api.met.no/weatherapi/locationforecast/2.0/documentation