From 74ee35708261cc5acecb7896c5bc736f4fa66680 Mon Sep 17 00:00:00 2001
From: Julia Signell <jsignell@gmail.com>
Date: Wed, 6 Aug 2025 10:49:46 -0400
Subject: [PATCH] Sort axis/dims before passing to numpy

---
 xarray/namedarray/core.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/xarray/namedarray/core.py b/xarray/namedarray/core.py
index dac8162ca45..3c5f90c819e 100644
--- a/xarray/namedarray/core.py
+++ b/xarray/namedarray/core.py
@@ -905,6 +905,13 @@ def reduce(
         if dim is not None:
             axis = self.get_axis_num(dim)
 
+        # sorting the axis ensures that the performance is consistent
+        # regardless of the input order of the dims
+        if isinstance(axis, tuple):
+            axis = tuple(sorted(axis))
+        elif isinstance(axis, list):
+            axis = sorted(axis)
+
         with warnings.catch_warnings():
             warnings.filterwarnings(
                 "ignore", r"Mean of empty slice", category=RuntimeWarning