Advanced Weather API

Introduction

The Advanced Weather API delivers spatio-temporally resolved, real-time weather information. The provided content comprises polygonal information about radar-based current precipitation, precipitation forecasts in different time slices, and local warnings about safety-relevant weather events for the present and future.

Request

Format

https://<baseURL>/weatherpolygons/<version>/<regionCode>?key=<apiKey>

Example

https://api.tomtom.com/weatherpolygons/v1/europe?key=<apiKey>

Parameters

Parameter	Description	Required	Example	Default
baseURL	Base URL for calling TomTom services.	Yes	api.tomtom.com	-
version	The version of the service to call.	Yes	v1	-
regionCode	The name of the product region. See the Region Coverage for supported regionCode values.	Yes	europe	-
apiKey	Authorization key for access to the API.	Yes	-	-

Headers

Header	Description	Required	Example	Default
[Accept-Encoding]	Requests that the response is compressed in the specified way. The fuelprices service supports http compression if desired. Currently, only gzip is supported.	No	gzip	-
[If-None-Match]	Provides the entity-tag (E-tag) of the requested resource as last received by the client. Allows efficient updates of cached information with a minimum amount of transaction overhead: The service can respond with a 304 (not modified) message if the data that would otherwise be provided has the same entity tag.	No	"4f3d2af4"	-
[If-Modified-Since]	Specifies the time stamp of the last actual update of the requested resource received by the client. Allows the service to respond with a 304 (not modified) message if no newer data is available.	No	Sat, 29 Oct 1994 19:43:31 GMT	-

Content

Plain GET messages must be used to create requests.

Response

The weather polygons are served in GeoJSON format. Root level of the response is a single FeatureCollection holding all weather polygons.

Every weather polygon is represented by a Feature, having a unique id and a set of properties. The enclosing FeatureCollection has an additional set of properties holding metadata such as the creation time of the response.

Response Codes

Code	Meaning and possible causes
200	OK
304	Not Modified: The requested content did not change since the last request, as indicated by the value(s) of the If-Modified-Since and/or or If-None-Match http header fields.
401	Unauthorized: The supplied API key is not valid for this request (or missing).
404	Not Found: The specified path was not valid. At least one of the path parameters was omitted or not entered correctly. If an unsupported or invalid country code was specified, the included response message provides a list of valid available country codes.
500	Internal Server Error: Oops.

Response Headers

Header	Description	Values
Content-Encoding	The service supports http compression if desired. Currently, only gzip is supported.	gzip
Content-Type	The format of the served resource. The service always provides data in GeoJSON.	application/json
Date	A timestamp specifying when the response was sent. Can be used by the client in the If-Modified-Since header field of subsequent requests in order to optimize the update procedure.	Example: "Wed, 20 Jul 2016 14:23:59 GMT"
Etag	Entity-tag of the served resource. Can be used by the client in the If-None-Match header field of subsequent requests in order to optimize the update procedure.	Example: "4f3d2af4"

Example Response

{
  "type" : "FeatureCollection",
  "features" : [ {
    "type" : "Feature",
    "id" : "0",
    "properties" : {
      "uniqueId" : "7ffffff",
      "category" : "precip",
      "type" : "rain",
      "level" : 0.86,
      "area" : 80.968,
      "children" : [ ],
      "parent" : "1",
      "countries" : [ "ESP" ]
    },
    "geometry" : {
      "type" : "Polygon",
      "coordinates" : [ [ [ -3.774, 37.513 ], [ -3.68, 37.568 ], [ -3.67, 37.628 ], [ -3.695, 37.653 ], [ -3.759, 37.608 ], [ -3.779, 37.518 ] ] ]
    },
    "bbox" : [ -3.779, 37.513, -3.67, 37.653 ]
  } ],
  "properties" : {
    "forecastOffset" : 15,
    "creationTime" : "2015-10-13T11:14:53.70Z",
    "timeStamp" : "2015-10-13T11:14:53.70Z",
    "rootTimeStamp" : "2015-10-13T11:14:53.70Z"
  }
}

Response Structure

FeatureCollection properties

Property	JSON data type	Description
forecastOffset	Number	The forecast horizon of the weather polygon in minutes. A zero stands for the present time.
creationTime	String	Time of the request in UTC as an ISO-8601-compliant date-time string of the form YYYY-MM-DDThh:mm:ssTZD (Year-Month-DayTHour:Minute:SecondTZD), e.g. "2015-06-09T10:00:00Z".
timeStamp	String	Time of which the weather polygons refer to (may be in the future) in UTC as an ISO-8601-compliant date-time string of the form YYYY-MM-DDThh:mm:ssTZD (Year-Month-DayTHour:Minute:SecondTZD), e.g. "2015-06-09T10:00:00Z".
rootTimeStamp	String	Time at which the weather polygons were measured/predicted in UTC as an ISO-8601-compliant date-time string of the form YYYY-MM-DDThh:mm:ssTZD (Year-Month-DayTHour:Minute:SecondTZD), e.g. "2015-06-09T10:00:00Z".

Feature properties

Property	JSON data type	Description
uniqueId	String	A unique and stable id of the current weather polygon.
category	String	The category of the weather polygon, e.g. "precip" (see section Category Values).
type	String	The type of the weather polygon, e.g. "rain" (see section Type Values).
level	Number	The level of the weather atom, i.e. a numeric value describing its magnitude.
area	Number	The area of the weather polygon in square kilometers (km²).
children	Array[String]	A list of Feature-Ids that represent polygons of the same category and type with the next higher level which lie inside the weather polygon. An empty array means no children.
parent	String	A single Feature-Id that represents the polygon of the next lower level which contains the weather polygon. An empty string means no parent.
countries	Array[String]	The list of countries, given as ISO 3166-1 alpha-3 country codes that intersect with the weather polygon.

Note: The Feature-Id is given by the id of the Feature object, see also the Feature specification.

Category values

Category	Description
precip	Regional information about the precipitation in the form of regions with different precipitation levels.
warning	Regional information about severe-weather conditions.

Type values

The type values are depending on the category value.

Type values for category "precip"

rain
snow
mixed
hail

Level values

The level values are depending on the category.

Level values for category "precip"

The value of a level specifies the precipitation intensity in mm/h.

Level values for category "warning"

Value	Description
0	moderate
1	heavy
2	extreme

Usage and Freshness

The weather polygons are updated regularly, typical frequencies being in the order of 15 minutes. Using the support for If-None-Match or If-Modified-Since header fields, higher update request frequencies can be used to minimize the delay between updated information being available in the server and being received by the client.

Region Coverage

Region	RegionCode
Europe	europe
USA	usa