Accessing and Reading Zarr

This page provides basic information on browsing and accessing the HRRR Zarr archive.

AWS Explorer

You may access the AWS Explorer web page and browse through all available data. While direct download through the browser is supported for individual chunks, you'll need to write code to decompress the data.

Path Format


[YYYYMMDD] - represents the UTC date format (e.g. 20210106).

[00-23]z - The two digits are the model run hour/reference time in UTC

[type] - This is either anl (analysis) for a zarr array with just the F00 analysis data or fcst (forecast) for a zarr array with forecast data at all available nonzero lead times (e.g. F01 - F48)

[level] - This is the model level. More information in the link on the next line

[var] - This is the variable stored in that level. For a complete list of the variables and levels click here

[chunk] - The conus HRRR data is broken up into 96 chunks or sections. View the map for an idea of the size and location of the chunks. The chunk identifier format differs depending on whether you have a anl or a fcst file. For fcst files the format is 0.y.x and for anl the format is y.x where the y and x are the corresponding numbers.

Python Access

We recommend three main ways of accessing the data:

The following code snippets are provided for "quick start" purposes. See the rest of the code documentation for further explanation and usage.

Option 1 - Chunk Access

Option 2 - Zarr library

Option 3 - xarray