diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index a61fa32dc..90ce84e97 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -137,44 +137,39 @@ jobs:
           mkdir -p ${GITHUB_WORKSPACE}/pyproj/proj_dir/share/proj
           cp "$VCPKG_INSTALLATION_ROOT/installed/${{ matrix.triplet }}/share/proj/"* ${GITHUB_WORKSPACE}/pyproj/proj_dir/share/proj/
 
+      # Part of cibuildwheel's settings are set dynamically so they cannot
+      # be moved to pyproject.toml
+      # avoid duplication between jobs by setting environment variables
+      # via GITHUB_ENV so they persist between steps
+
+      - name: Setup cibuildwheel environment (all platforms)
+        run: |
+          echo "PROJ_WHEEL='true'" >> "$GITHUB_ENV"
+          echo "PROJ_NETWORK=ON" >> "$GITHUB_ENV"
+          echo "PROJ_VERSION=${{ env.PROJ_VERSION }}" >> "$GITHUB_ENV"
+          echo "CIBW_ARCHS=${{ matrix.arch }}" >> "$GITHUB_ENV"
+
+      - name: Setup additional environment (linux)
+        if: ${{ startswith( matrix.os , 'ubuntu' ) }}
+        run: |
+          echo "PROJ_DIR=/project/pyproj/proj_dir" >> "$GITHUB_ENV"
+
+      - name: Setup additional environment (macos)
+        if: ${{ startswith( matrix.os , 'macos' ) }}
+        run: |
+          echo "PROJ_DIR=${GITHUB_WORKSPACE}/pyproj/proj_dir" >> "$GITHUB_ENV"
+          echo 'CIBW_ENVIRONMENT=CMAKE_OSX_ARCHITECTURES='${{ matrix.cmake_osx_architectures }}' MACOSX_DEPLOYMENT_TARGET=${{ matrix.macos_deployment_target }} LDFLAGS="${LDFLAGS} -Wl,-rpath,${GITHUB_WORKSPACE}/pyproj/proj_dir/lib"' >> "$GITHUB_ENV"
+
+      - name: Setup additional environment (windows)
+        if: ${{ startswith( matrix.os , 'windows' ) }}
+        # repair-wheel: add Windows System32 explicitly to the path
+        # see https://github.com/adang1345/delvewheel/issues/54
+        run: |
+          echo 'PROJ_DIR=$VCPKG_INSTALLATION_ROOT/installed/${{ matrix.triplet }}' >> "$GITHUB_ENV"
+          echo 'CIBW_REPAIR_WHEEL_COMMAND="delvewheel repair --add-path C:/Windows/System32 --add-path C:/vcpkg/installed/${{ matrix.triplet }}/bin -w {dest_dir} {wheel}"' >> "$GITHUB_ENV"
+
       - name: Build wheels
         uses: pypa/cibuildwheel@v4.3.1
-        env:
-          CIBW_ARCHS: ${{ matrix.arch }}
-          CIBW_ENVIRONMENT_LINUX:
-            PROJ_WHEEL=true
-            PROJ_NETWORK=ON
-            PROJ_VERSION=${{ env.PROJ_VERSION }}
-            PROJ_DIR=/project/pyproj/proj_dir
-          CIBW_ENVIRONMENT_MACOS:
-            PROJ_WHEEL=true
-            PROJ_NETWORK=ON
-            PROJ_VERSION=${{ env.PROJ_VERSION }}
-            PROJ_DIR=${GITHUB_WORKSPACE}/pyproj/proj_dir
-            CMAKE_OSX_ARCHITECTURES='${{ matrix.cmake_osx_architectures }}'
-            MACOSX_DEPLOYMENT_TARGET=${{ matrix.macos_deployment_target }}
-            LDFLAGS="${LDFLAGS} -Wl,-rpath,${GITHUB_WORKSPACE}/pyproj/proj_dir/lib"
-          CIBW_ENVIRONMENT_WINDOWS:
-            PROJ_WHEEL=true
-            PROJ_NETWORK=ON
-            PROJ_VERSION=${{ env.PROJ_VERSION }}
-            PROJ_DIR=$VCPKG_INSTALLATION_ROOT/installed/${{ matrix.triplet }}
-          # Rename Git's link.exe to avoid conflict with MSVC link.exe (meson issue)
-          CIBW_BEFORE_BUILD_WINDOWS: >
-            python -m pip install delvewheel &&
-            if exist "C:\Program Files\Git\usr\bin\link.exe" (rename "C:\Program Files\Git\usr\bin\link.exe" "link.exe.bak")
-          # Add Windows System32 explicitly to the path https://github.com/adang1345/delvewheel/issues/54
-          CIBW_REPAIR_WHEEL_COMMAND_WINDOWS: "delvewheel repair --add-path C:/Windows/System32 --add-path C:/vcpkg/installed/${{ matrix.triplet }}/bin -w {dest_dir} {wheel}"
-          CIBW_BEFORE_ALL_LINUX: bash ./ci/proj-compile-wheels.sh
-          CIBW_BEFORE_ALL_MACOS: bash ./ci/proj-compile-wheels.sh
-          CIBW_TEST_REQUIRES: cython pytest numpy --config-settings=setup-args="-Dallow-noblas=true"
-          # Install numpy first so Shapely can find numpy headers during build
-          CIBW_BEFORE_TEST: python -m pip install numpy && python -m pip install shapely pandas xarray || echo "Optional requirements install failed"
-          CIBW_TEST_COMMAND: >
-            pyproj -v &&
-            python -c "import pyproj; pyproj.Proj(init='epsg:4269')"  &&
-            cp -r {package}/test . &&
-            python -m pytest test -v -s
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v7
diff --git a/pyproject.toml b/pyproject.toml
index f003d114a..fae5f557d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -104,6 +104,34 @@ include = ["pyproj", "pyproj.*"]
 [tool.setuptools.dynamic]
 version = {attr = "pyproj.__version__"}
 
+[tool.cibuildwheel]
+test-groups = ["test"]
+test-sources = ["test"]
+test-command = [
+    "pyproj -v",
+    '''python -c "import pyproj; pyproj.Proj(init='epsg:4269')"''',
+    "python -m pytest test -v -s",
+]
+environment-pass = [
+    "PROJ_DIR",
+    "PROJ_NETWORK",
+    "PROJ_VERSION",
+    "PROJ_WHEEL",
+]
+
+[tool.cibuildwheel.config-settings]
+setup-args = "-Dallow-noblas=true"
+
+[tool.cibuildwheel.linux]
+before-all = "bash ./ci/proj-compile-wheels.sh"
+
+[tool.cibuildwheel.macos]
+before-all = "bash ./ci/proj-compile-wheels.sh"
+
+[tool.cibuildwheel.windows]
+# Rename Git's link.exe to avoid conflict with MSVC link.exe (meson issue)
+before-build = 'if exist "C:\Program Files\Git\usr\bin\link.exe" (rename "C:\Program Files\Git\usr\bin\link.exe" "link.exe.bak")'
+
 [tool.ruff]
 line-length = 88
 fix = true
diff --git a/setup.py b/setup.py
index 54d682065..a178b41d8 100644
--- a/setup.py
+++ b/setup.py
@@ -4,6 +4,7 @@
 import shutil
 import subprocess
 import sys
+from functools import partial
 from pathlib import Path
 
 from setuptools import Extension, setup
@@ -69,27 +70,28 @@ def get_proj_dir() -> Path:
     This function finds the base PROJ directory.
     """
     proj_dir_environ = os.environ.get("PROJ_DIR")
-    proj_dir: Path | None = None
+    log = partial(print, file=sys.stderr)
     if proj_dir_environ is not None:
         proj_dir = Path(proj_dir_environ)
-    if proj_dir is None and INTERNAL_PROJ_DIR.exists():
+        log("Using proj specified by environment variable PROJ_DIR", end=" ")
+    elif INTERNAL_PROJ_DIR.exists():
         proj_dir = INTERNAL_PROJ_DIR
-        print(f"Internally compiled directory being used {INTERNAL_PROJ_DIR}.")
-    elif proj_dir is None and not INTERNAL_PROJ_DIR.exists():
-        proj = shutil.which("proj", path=sys.prefix)
-        if proj is None:
-            proj = shutil.which("proj")
+        log("Using proj from internal compiled directory", end=" ")
+    else:
+        proj = shutil.which("proj", path=sys.prefix) or shutil.which("proj")
         if proj is None:
             raise SystemExit(
                 "proj executable not found. Please set the PROJ_DIR variable. "
                 "For more information see: "
                 "https://pyproj4.github.io/pyproj/stable/installation.html"
             )
-        proj_dir = Path(proj).parent.parent
-    elif proj_dir is not None and proj_dir.exists():
-        print("PROJ_DIR is set, using existing PROJ installation..\n")
-    else:
-        raise SystemExit(f"ERROR: Invalid path for PROJ_DIR {proj_dir}")
+        proj_dir = Path(proj).parents[1]
+        log("Using proj auto-discovered executable", end=" ")
+    log(proj_dir)
+    if not proj_dir.exists():
+        raise SystemExit(f"ERROR: not such file or directory {proj_dir}")
+    if not proj_dir.is_dir():
+        raise SystemExit(f"ERROR: {proj_dir} exists but is not a directory")
     return proj_dir