Release notes for v2024.09.0 (#9480)

Author: owenlittlejohns

doc/whats-new.rst

@@ -15,15 +15,21 @@ What's New
     np.random.seed(123456)
 
 
-.. _whats-new.2024.07.1:
+.. _whats-new.2024.09.0:
 
-v2024.07.1 (unreleased)
------------------------
+v2024.09.0 (Sept 11, 2024)
+--------------------------
+This release drops support for Python 3.9, and adds support for grouping by :ref:`multiple arrays <groupby.multiple>`, while providing numerous performance improvements and bug fixes.
+
+Thanks to the 33 contributors to this release:
+Alfonso Ladino, Andrew Scherer, Anurag Nayak, David Hoese, Deepak Cherian, Diogo Teles Sant'Anna, Dom, Elliott Sales de Andrade, Eni, Holly Mandel, Illviljan, Jack Kelly, Julius Busecke, Justus Magin, Kai Mühlbauer, Manish Kumar Gupta, Matt Savoie, Maximilian Roos, Michele Claus, Miguel Jimenez, Niclas Rieger, Pascal Bourgault, Philip Chmielowiec, Spencer Clark, Stephan Hoyer, Tao Xin, Tiago Sanona, TimothyCera-NOAA, Tom Nicholas, Tom White, Virgile Andreani, oliverhiggs and tiago
 
 New Features
 ~~~~~~~~~~~~
 
-- Add :py:attr:`~core.accessor_dt.DatetimeAccessor.days_in_year` and :py:attr:`~core.accessor_dt.DatetimeAccessor.decimal_year` to the Datetime accessor on DataArrays. (:pull:`9105`).
+- Add :py:attr:`~core.accessor_dt.DatetimeAccessor.days_in_year` and
+  :py:attr:`~core.accessor_dt.DatetimeAccessor.decimal_year` to the
+  ``DatetimeAccessor`` on ``xr.DataArray``. (:pull:`9105`).
   By `Pascal Bourgault <https://github.com/aulemahal>`_.
 
 Performance
@@ -38,6 +44,8 @@ Performance
   By `Deepak Cherian <https://github.com/dcherian>`_.
 - Allow data variable specific ``constant_values`` in the dataset ``pad`` function (:pull:`9353``).
   By `Tiago Sanona <https://github.com/tsanona>`_.
+- Speed up grouping by avoiding deep-copy of non-dimension coordinates (:issue:`9426`, :pull:`9393`)
+  By `Deepak Cherian <https://github.com/dcherian>`_.
 
 Breaking changes
 ~~~~~~~~~~~~~~~~
@@ -61,11 +69,6 @@ Breaking changes
     zarr                    2.14      2.16
   ===================== =========  =======
 
-
-Deprecations
-~~~~~~~~~~~~
-
-
 Bug fixes
 ~~~~~~~~~
 
@@ -90,24 +93,12 @@ Bug fixes
   (:issue:`9408`, :pull:`9413`).
   By `Oliver Higgs <https://github.com/oliverhiggs>`_.
 
-Performance
-~~~~~~~~~~~
-
-- Speed up grouping by avoiding deep-copy of non-dimension coordinates (:issue:`9426`, :pull:`9393`)
-  By `Deepak Cherian <https://github.com/dcherian>`_.
-
-Documentation
-~~~~~~~~~~~~~
-
-
 Internal Changes
 ~~~~~~~~~~~~~~~~
 
 - Re-enable testing ``pydap`` backend with ``numpy>=2`` (:pull:`9391`).
   By `Miguel Jimenez <https://github.com/Mikejmnez>`_ .
 
-
-
 .. _whats-new.2024.07.0:
 
 v2024.07.0 (Jul 30, 2024)