diff --git a/xarray/core/toolzcompat.py b/xarray/core/toolzcompat.py
index 5eeb9681afc..4632419a845 100644
--- a/xarray/core/toolzcompat.py
+++ b/xarray/core/toolzcompat.py
@@ -51,5 +51,6 @@ def sliding_window(n, seq):
         *(
             collections.deque(itertools.islice(it, i), 0) or it
             for i, it in enumerate(itertools.tee(seq, n))
-        )
+        ),
+        strict=False,
     )
diff --git a/xarray/groupers.py b/xarray/groupers.py
index 434bd764fa4..0ba59f726df 100644
--- a/xarray/groupers.py
+++ b/xarray/groupers.py
@@ -24,6 +24,7 @@
 from xarray.core.groupby import T_Group, _DummyGroup
 from xarray.core.indexes import safe_cast_to_index
 from xarray.core.resample_cftime import CFTimeGrouper
+from xarray.core.toolzcompat import sliding_window
 from xarray.core.types import (
     Bins,
     DatetimeLike,
@@ -31,7 +32,6 @@
     ResampleCompatible,
     SideOptions,
 )
-from xarray.core.toolzcompat import sliding_window
 from xarray.core.variable import Variable
 
 __all__ = [
@@ -495,7 +495,7 @@ def season_to_month_tuple(seasons: Sequence[str]) -> tuple[tuple[int, ...], ...]
     initials = "JFMAMJJASOND"
     starts = dict(
         ("".join(s), i + 1)
-        for s, i in zip(sliding_window(2, initials + "J"), range(12))
+        for s, i in zip(sliding_window(2, initials + "J"), range(12), strict=False)
     )
     result: list[tuple[int, ...]] = []
     for i, season in enumerate(seasons):
@@ -602,7 +602,7 @@ class SeasonResampler(Resampler):
 
     def __post_init__(self):
         self.season_inds = season_to_month_tuple(self.seasons)
-        self.season_tuples = dict(zip(self.seasons, self.season_inds))
+        self.season_tuples = dict(zip(self.seasons, self.season_inds, strict=False))
 
     def factorize(self, group):
         if group.ndim != 1:
@@ -624,7 +624,7 @@ def factorize(self, group):
         season_label = np.full(group.shape, "", dtype=f"U{nstr}")
 
         # offset years for seasons with December and January
-        for season_str, season_ind in zip(seasons, season_inds):
+        for season_str, season_ind in zip(seasons, season_inds, strict=False):
             season_label[month.isin(season_ind)] = season_str
             if "DJ" in season_str:
                 after_dec = season_ind[season_str.index("D") + 1 :]
@@ -651,14 +651,16 @@ def factorize(self, group):
         )
 
         sbins = first_items.values.astype(int)
-        group_indices = [slice(i, j) for i, j in zip(sbins[:-1], sbins[1:])]
+        group_indices = [
+            slice(i, j) for i, j in zip(sbins[:-1], sbins[1:], strict=False)
+        ]
         group_indices += [slice(sbins[-1], None)]
 
         # Make sure the first and last timestamps
         # are for the correct months,if not we have incomplete seasons
         unique_codes = np.arange(len(unique_coord))
         if self.drop_incomplete:
-            for idx, slicer in zip([0, -1], (slice(1, None), slice(-1))):
+            for idx, slicer in zip([0, -1], (slice(1, None), slice(-1)), strict=False):
                 stamp_year, stamp_season = frame.index[idx]
                 code = seasons.index(stamp_season)
                 stamp_month = season_inds[code][idx]