diff --git a/.github/workflows/citation_file_validator.yml b/.github/workflows/citation_file_validator.yml
index 43a4d5c444..e957d40f86 100644
--- a/.github/workflows/citation_file_validator.yml
+++ b/.github/workflows/citation_file_validator.yml
@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out a copy of the repository
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Check whether the citation metadata from CITATION.cff is valid
         uses: citation-file-format/cffconvert-github-action@2.0.0
diff --git a/.github/workflows/create-condalock-file.yml b/.github/workflows/create-condalock-file.yml
index 9aefad7498..a88f919c17 100644
--- a/.github/workflows/create-condalock-file.yml
+++ b/.github/workflows/create-condalock-file.yml
@@ -20,10 +20,10 @@ jobs:
     name: Create conda lock file for latest Python
     runs-on: 'ubuntu-latest'
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           auto-update-conda: true
           activate-environment: esmvaltool-fromlock
@@ -35,7 +35,7 @@ jobs:
         run: |
           conda update -n base -c conda-forge conda
           conda --version
-          # setup-miniconda@v2 installs an old conda and mamba
+          # setup-miniconda@v3 installs an old conda and mamba
           # forcing a modern mamba updates both mamba and conda
           conda install -c conda-forge "mamba>=1.4.8"
           conda config --show-sources
diff --git a/.github/workflows/install-from-conda.yml b/.github/workflows/install-from-conda.yml
index 55897e7fe4..862fd0aad6 100644
--- a/.github/workflows/install-from-conda.yml
+++ b/.github/workflows/install-from-conda.yml
@@ -23,7 +23,7 @@ jobs:
         python-version: ["3.9", "3.10", "3.11"]
     name: Linux Python ${{ matrix.python-version }}
     steps:
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           python-version: ${{ matrix.python-version }}
           miniforge-version: "latest"
@@ -44,7 +44,7 @@ jobs:
           esmvaltool version 2>&1 | tee conda_install_linux_artifacts_python_${{ matrix.python-version }}/version.txt
       - name: Upload artifacts
         if: ${{ always() }}  # upload artifacts even if fail
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: Conda_Install_Linux_python_${{ matrix.python-version }}
           path: conda_install_linux_artifacts_python_${{ matrix.python-version }}
@@ -61,7 +61,7 @@ jobs:
 #    name: OSX Python ${{ matrix.python-version }}
 #    steps:
 #      - uses: actions/checkout@v2
-#      - uses: conda-incubator/setup-miniconda@v2
+#      - uses: conda-incubator/setup-miniconda@v3
 #        with:
 #          python-version: ${{ matrix.python-version }}
 #          miniconda-version: "latest"
@@ -82,7 +82,7 @@ jobs:
 #      - run: esmvaltool version 2>&1 | tee conda_install_osx_artifacts_python_${{ matrix.python-version }}/version.txt
 #      - name: Upload artifacts
 #        if: ${{ always() }}  # upload artifacts even if fail
-#        uses: actions/upload-artifact@v2
+#        uses: actions/upload-artifact@v4
 #        with:
 #          name: Conda_Install_OSX_python_${{ matrix.python-version }}
 #          path: conda_install_osx_artifacts_python_${{ matrix.python-version }}
diff --git a/.github/workflows/install-from-condalock-file.yml b/.github/workflows/install-from-condalock-file.yml
index a209c06f32..ef19a4cb15 100644
--- a/.github/workflows/install-from-condalock-file.yml
+++ b/.github/workflows/install-from-condalock-file.yml
@@ -34,10 +34,10 @@ jobs:
       fail-fast: false
     name: Linux Python ${{ matrix.python-version }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           activate-environment: esmvaltool-fromlock
           python-version: ${{ matrix.python-version }}
@@ -57,7 +57,7 @@ jobs:
       - run: pytest -n 2 -m "not installation"
       - name: Upload artifacts
         if: ${{ always() }}  # upload artifacts even if fail
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: Source_Install_Linux_python_${{ matrix.python-version }}
           path: source_install_linux_artifacts_python_${{ matrix.python-version }}
diff --git a/.github/workflows/install-from-source.yml b/.github/workflows/install-from-source.yml
index 2e24b8f049..6e9c1de19a 100644
--- a/.github/workflows/install-from-source.yml
+++ b/.github/workflows/install-from-source.yml
@@ -23,10 +23,10 @@ jobs:
       fail-fast: false
     name: Linux Python ${{ matrix.python-version }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           activate-environment: esmvaltool
           environment-file: environment.yml
@@ -47,7 +47,7 @@ jobs:
           esmvaltool version 2>&1 | tee source_install_linux_artifacts_python_${{ matrix.python-version }}/version.txt
       - name: Upload artifacts
         if: ${{ always() }}  # upload artifacts even if fail
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: Source_Install_Linux_python_${{ matrix.python-version }}
           path: source_install_linux_artifacts_python_${{ matrix.python-version }}
@@ -64,7 +64,7 @@ jobs:
 #    name: OSX Python ${{ matrix.python-version }}
 #    steps:
 #      - uses: actions/checkout@v2
-#      - uses: conda-incubator/setup-miniconda@v2
+#      - uses: conda-incubator/setup-miniconda@v3
 #        with:
 #          activate-environment: esmvaltool
 #          environment-file: environment.yml
@@ -79,7 +79,7 @@ jobs:
 #      - run: esmvaltool version 2>&1 | tee source_install_osx_artifacts_python_${{ matrix.python-version }}/version.txt
 #      - name: Upload artifacts
 #        if: ${{ always() }}  # upload artifacts even if fail
-#        uses: actions/upload-artifact@v2
+#        uses: actions/upload-artifact@v4
 #        with:
 #          name: Source_Install_OSX_python_${{ matrix.python-version }}
 #          path: source_install_osx_artifacts_python_${{ matrix.python-version }}
diff --git a/.github/workflows/pypi-build-and-deploy.yml b/.github/workflows/pypi-build-and-deploy.yml
index f1ed214e12..4dff1e4d69 100644
--- a/.github/workflows/pypi-build-and-deploy.yml
+++ b/.github/workflows/pypi-build-and-deploy.yml
@@ -14,7 +14,7 @@ jobs:
     name: Build and publish ESMValTool on PyPi
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - name: Set up Python 3.11
diff --git a/.github/workflows/run-tests-monitor.yml b/.github/workflows/run-tests-monitor.yml
index c381bfca9e..52cc282235 100644
--- a/.github/workflows/run-tests-monitor.yml
+++ b/.github/workflows/run-tests-monitor.yml
@@ -26,10 +26,10 @@ jobs:
         python-version: ["3.9", "3.10", "3.11"]
     name: Linux Python ${{ matrix.python-version }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           activate-environment: esmvaltool
           environment-file: environment.yml
@@ -58,7 +58,7 @@ jobs:
         run: python tests/parse_pymon.py
       - name: Upload artifacts
         if: ${{ always() }}  # upload artifacts even if fail
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: Test_Linux_python_${{ matrix.python-version }}
           path: test_linux_artifacts_python_${{ matrix.python-version }}
@@ -68,14 +68,16 @@ jobs:
     strategy:
       matrix:
         python-version: ["3.9", "3.10", "3.11"]
+        architecture: ["x64"]  # need to force Intel, arm64 builds have issues
       fail-fast: false
     name: OSX Python ${{ matrix.python-version }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
+          architecture: ${{ matrix.architecture }}
           activate-environment: esmvaltool
           environment-file: environment_osx.yml
           python-version: ${{ matrix.python-version }}
@@ -107,7 +109,7 @@ jobs:
         run: python tests/parse_pymon.py
       - name: Upload artifacts
         if: ${{ always() }}  # upload artifacts even if fail
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: Test_OSX_python_${{ matrix.python-version }}
           path: test_osx_artifacts_python_${{ matrix.python-version }}
diff --git a/.github/workflows/test-development.yml b/.github/workflows/test-development.yml
index cab6489548..7ff8c93680 100644
--- a/.github/workflows/test-development.yml
+++ b/.github/workflows/test-development.yml
@@ -30,10 +30,10 @@ jobs:
         python-version: ["3.9", "3.10", "3.11"]
     name: Linux Python ${{ matrix.python-version }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           activate-environment: esmvaltool
           environment-file: environment.yml
@@ -62,7 +62,7 @@ jobs:
         run: pytest -n 2 -m "not installation" 2>&1 | tee develop_test_linux_artifacts_python_${{ matrix.python-version }}/test_report.txt
       - name: Upload artifacts
         if: ${{ always() }}  # upload artifacts even if fail
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: Develop_Test_Linux_python_${{ matrix.python-version }}
           path: develop_test_linux_artifacts_python_${{ matrix.python-version }}
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 8291bc6914..49f1a14003 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -23,10 +23,10 @@ jobs:
         python-version: ["3.9", "3.10", "3.11"]
     name: Linux Python ${{ matrix.python-version }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           activate-environment: esmvaltool
           environment-file: environment.yml
@@ -63,7 +63,7 @@ jobs:
         run: pytest -n 2 -m "not installation" 2>&1 | tee test_linux_artifacts_python_${{ matrix.python-version }}/test_report.txt
       - name: Upload artifacts
         if: ${{ always() }}  # upload artifacts even if fail
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: Test_Linux_python_${{ matrix.python-version }}
           path: test_linux_artifacts_python_${{ matrix.python-version }}
@@ -73,14 +73,16 @@ jobs:
     strategy:
       matrix:
         python-version: ["3.9", "3.10", "3.11"]
+        architecture: ["x64"]  # need to force Intel, arm64 builds have issues
       fail-fast: false
     name: OSX Python ${{ matrix.python-version }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
+          architecture: ${{ matrix.architecture }}
           activate-environment: esmvaltool
           environment-file: environment_osx.yml
           python-version: ${{ matrix.python-version }}
@@ -112,7 +114,7 @@ jobs:
         run: pytest -n 2 -m "not installation" 2>&1 | tee test_osx_artifacts_python_${{ matrix.python-version }}/test_report.txt
       - name: Upload artifacts
         if: ${{ always() }}  # upload artifacts even if fail
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v4
         with:
           name: Test_OSX_python_${{ matrix.python-version }}
           path: test_osx_artifacts_python_${{ matrix.python-version }}