diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 8f6816285c..faa0aea2cc 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -90,7 +90,7 @@ jobs:
         # may break the conda-forge libraries trying to use newer glibc versions
         run: |
           python -m pip install \
-          --index-url https://pypi.anaconda.org/scipy-wheels-nightly/simple/ \
+          --index-url https://pypi.anaconda.org/scientific-python-nightly-wheels/simple/ \
           --trusted-host pypi.anaconda.org \
           --no-deps --pre --upgrade \
           matplotlib \
diff --git a/satpy/tests/reader_tests/gms/test_gms5_vissr_l1b.py b/satpy/tests/reader_tests/gms/test_gms5_vissr_l1b.py
index 31482f1e10..f4908c0a2b 100644
--- a/satpy/tests/reader_tests/gms/test_gms5_vissr_l1b.py
+++ b/satpy/tests/reader_tests/gms/test_gms5_vissr_l1b.py
@@ -9,14 +9,20 @@
 import xarray as xr
 from pyresample.geometry import AreaDefinition
 
-import satpy.readers.gms.gms5_vissr_format as fmt
-import satpy.readers.gms.gms5_vissr_l1b as vissr
-import satpy.readers.gms.gms5_vissr_navigation as nav
 import satpy.tests.reader_tests.gms.test_gms5_vissr_data as real_world
 from satpy.readers import FSFile
-from satpy.tests.reader_tests.utils import get_jit_methods
+from satpy.tests.reader_tests.utils import get_jit_methods, skip_numba_unstable_if_missing
 from satpy.tests.utils import make_dataid
 
+try:
+    import satpy.readers.gms.gms5_vissr_format as fmt
+    import satpy.readers.gms.gms5_vissr_l1b as vissr
+    import satpy.readers.gms.gms5_vissr_navigation as nav
+except ImportError as err:
+    if skip_numba_unstable_if_missing():
+        pytest.skip(f"Numba is not compatible with unstable NumPy: {err!s}", allow_module_level=True)
+    raise
+
 
 @pytest.fixture(params=[False, True], autouse=True)
 def disable_jit(request, monkeypatch):
diff --git a/satpy/tests/reader_tests/gms/test_gms5_vissr_navigation.py b/satpy/tests/reader_tests/gms/test_gms5_vissr_navigation.py
index 47c5fd044c..144139a07a 100644
--- a/satpy/tests/reader_tests/gms/test_gms5_vissr_navigation.py
+++ b/satpy/tests/reader_tests/gms/test_gms5_vissr_navigation.py
@@ -3,8 +3,14 @@
 import numpy as np
 import pytest
 
-import satpy.readers.gms.gms5_vissr_navigation as nav
-from satpy.tests.reader_tests.utils import get_jit_methods
+from satpy.tests.reader_tests.utils import get_jit_methods, skip_numba_unstable_if_missing
+
+try:
+    import satpy.readers.gms.gms5_vissr_navigation as nav
+except ImportError as err:
+    if skip_numba_unstable_if_missing():
+        pytest.skip(f"Numba is not compatible with unstable NumPy: {err!s}", allow_module_level=True)
+    raise
 
 # Navigation references computed with JMA's Msial library (files
 # VISSR_19960217_2331_IR1.A.IMG and VISSR_19960217_2331_VIS.A.IMG). The VIS
diff --git a/satpy/tests/reader_tests/utils.py b/satpy/tests/reader_tests/utils.py
index 9415ac56ec..05e6d9cb18 100644
--- a/satpy/tests/reader_tests/utils.py
+++ b/satpy/tests/reader_tests/utils.py
@@ -18,6 +18,7 @@
 """Utilities for reader tests."""
 
 import inspect
+import os
 
 
 def default_attr_processor(root, attr):
@@ -61,3 +62,23 @@ def get_jit_methods(module):
 
 def _is_jit_method(obj):
     return hasattr(obj, "py_func")
+
+
+def skip_numba_unstable_if_missing():
+    """Determine if numba-based tests should be skipped during unstable CI tests.
+
+    If numba fails to import it could be because numba is not compatible with
+    a newer version of numpy. This is very likely to happen in the
+    unstable/experimental CI environment. This function returns ``True`` if
+    numba-based tests should be skipped if ``numba`` could not
+    be imported *and* we're in the unstable environment. We determine if we're
+    in this CI environment by looking for the ``UNSTABLE="1"``
+    environment variable.
+
+    """
+    try:
+        import numba
+    except ImportError:
+        numba = None
+
+    return numba is None and os.environ.get("UNSTABLE", "0") in ("1", "true")