Heatmaps

  • The heatmapTiles endpoint delivers pollen heatmaps as tile overlays, which are collections of 256x256 pixel image tiles displayed on top of Google Maps.

  • Tile coordinates (X,Y) determine the grid position, with (0,0) at the northwest corner and increasing values eastward for X and southward for Y.

  • Zoom level (Z) controls map content size and grid dimensions, ranging from 0 (entire world) to 16, influencing tile coordinates validity.

  • To request heatmap tiles, use the heatmapTiles endpoint with required parameters: API key, heatmap type, zoom level, and tile coordinates (X,Y).

  • You can overlay these pollen heatmap tiles onto existing maps for visualization, enhancing applications with pollen information.

The heatmapTiles endpoint provides pollen-related heatmaps through tile overlay. A tile overlay is a collection of image tiles that can be displayed on top of Google Maps. Each image tile is 256 x 256 pixels.

The tile overlay is a grid assembled from a collection of tiles, each assigned (X,Y) coordinates. The tile with coordinates (0,0) is always at the northwest corner of the map. The X values increase from west to east, while the Y values increase from north to south.

The zoom level determines how large or small the contents of a map appear in a map view. The tile grid size is determined by scaling the X and Y coordinates exponentially by the zoom level.

gridSizeX = XzoomLevel
gridSizeY = YzoomLevel

For example, at a zoom level of 2, the world map is represented using a 4 x 4 matrix, for a total of 16 tiles.

The following image shows a TREE_UPI heatmap of the entire world, sectioned into tiles that can be accessed at a zoom level of 2.

A heatmap of the entire world as a 4 by 4 grid.

See Map and Tile coordinates for additional details.

You can request current pollen heatmap tiles using the heatmapTiles endpoint by sending an HTTP GET request to:

https://pollen.googleapis.com/v1/mapTypes/TYPE/heatmapTiles/Z/X/Y?key=YOUR_API_KEY

About the heatmap endpoint

All parameters listed below are required for a successful request:

  • KEY: Your application's API key. This key identifies your application for purposes of quota management. Learn how to get a key.
  • TYPE: The type of heatmap to return. See allowed values.
  • Z: Zoom level that determines how large or small the contents of a map appear in a map view. Allowed values are 0-16, where a value of 0 displays the entire world in a single tile.
  • X,Y: The tile coordinates relatively to the north east corner (0,0). X values increase from west to east and Y values increase from north to south. Coordinates must be valid for the specified zoom level. For example, if you set the zoom level to 2 and request a tile at coordinates (10,10), the API returns an error.

Example heatmap request

The image above shows a TREE_UPI heatmap with a zoom level of 2, along with the coordinates of each tile. The following example uses the heatmapTiles endpoint to request the tile at coordinates (2,1):

https://pollen.googleapis.com/v1/mapTypes/TREE_UPI/heatmapTiles/2/2/1?key=YOUR_API_KEY

The tile appears as an image that can be overlaid on a map:

An example of a heatmap tile using the TREE_UPI map.

For more information on overlaying tiles on top of the default map, see Overlay Map Types.