diff --git a/.gitignore b/.gitignore
index 5647313e..514914b3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -61,3 +61,4 @@ thirdparty/pyplot_module.F90
 .claude
 docs/_build/
 build*/
+.venv/
diff --git a/Makefile b/Makefile
index f4934ab6..b9e1e3e6 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ NVHPC_HPCX := $(NVHPC_ROOT)/comm_libs/13.0/hpcx/hpcx-2.25.1/ompi
 NVHPC_BUILD_DIR := build_nvfortran
 NVHPC_ACC_BUILD_DIR := build_nvfortran_acc
 
-.PHONY: all configure reconfigure build build-deterministic build-deterministic-nopy test test-nopy test-fast test-slow test-regression test-all test-golden-main test-golden-tag test-golden install clean nvfortran nvfortran-test nvfortran-test-nopy nvfortran-configure nvfortran-clean
+.PHONY: all configure reconfigure build build-deterministic build-deterministic-nopy test test-nopy test-fast test-slow test-regression test-all test-golden-main test-golden-tag test-golden install clean venv nvfortran nvfortran-test nvfortran-test-nopy nvfortran-configure nvfortran-clean
 .PHONY: nvfortran-acc nvfortran-acc-test nvfortran-acc-test-nopy nvfortran-acc-configure nvfortran-acc-clean
 all: build
 
@@ -98,6 +98,12 @@ test-golden: build-deterministic-nopy
 test-golden-fast: build
 	cd $(BUILD_DIR) && ctest --output-on-failure $(if $(filter 1,$(VERBOSE)),-V) -L "golden_record" $(if $(TEST),-R "$(TEST)")
 
+venv:
+	./setup-venv.sh
+
+venv-nopy:
+	./setup-venv.sh --no-pysimple
+
 doc: configure
 	cmake --build --preset default --target doc
 
diff --git a/pyproject.toml b/pyproject.toml
index aa572f45..39698a3e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,6 +17,3 @@ cmake.define.CMAKE_CACHE_DIR = "build"
 wheel.packages = ["python/pysimple"]
 wheel.install-dir = "pysimple"
 wheel.exclude = []
-
-[project.package-data]
-pysimple = ["data/*.dat"]
diff --git a/requirements.txt b/requirements.txt
index 77fb5fe1..8aa97c79 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,19 +1,20 @@
 # Python dependencies for SIMPLE
-# Pin exact versions for reproducibility in CI
+# Use minimum versions for compatibility across Python releases.
+# Exact pins break on newer Python versions that lack prebuilt wheels.
 
 # Core dependencies
-numpy==2.2.6
-scikit-build-core==0.10.0
+numpy>=2.2
+scikit-build-core>=0.10
 
-# F90wrap - pinned to release version
+# F90wrap - pinned to release version (API-sensitive)
 f90wrap==0.2.16
 
-# Optional dependencies for testing
-pytest==7.4.3
-pytest-cov==6.2.1
-netCDF4==1.7.2
+# Testing
+pytest>=7.4
+pytest-cov>=6.0
+netCDF4>=1.7
 
-# Optional dependencies for examples/plotting
-matplotlib==3.9.4
-scipy==1.15.2
-shapely==2.0.5
+# Plotting and examples
+matplotlib>=3.9
+scipy>=1.15
+shapely>=2.0
diff --git a/setup-venv.sh b/setup-venv.sh
new file mode 100755
index 00000000..90f4cfda
--- /dev/null
+++ b/setup-venv.sh
@@ -0,0 +1,65 @@
+#!/bin/bash
+# Create and populate a Python virtual environment for SIMPLE.
+# Usage: ./setup-venv.sh [--no-pysimple]
+#
+# Options:
+#   --no-pysimple   Skip building pysimple (Fortran-Python bindings).
+#                   Use this if you only need Python test/plot dependencies.
+#
+# Prerequisites (system packages):
+#   - python3 (>= 3.9) with venv module
+#   - gfortran, cmake, ninja-build
+#   - libnetcdff-dev (or netcdf-fortran-devel), liblapack-dev
+#   See docs/PREREQUISITES.md for distro-specific install commands.
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+VENV_DIR="${SCRIPT_DIR}/.venv"
+BUILD_PYSIMPLE=1
+
+for arg in "$@"; do
+    case "$arg" in
+        --no-pysimple) BUILD_PYSIMPLE=0 ;;
+        -h|--help)
+            sed -n '2,/^$/s/^# //p' "$0"
+            exit 0
+            ;;
+        *)
+            echo "Unknown option: $arg" >&2
+            exit 1
+            ;;
+    esac
+done
+
+echo "Creating virtual environment in ${VENV_DIR} ..."
+python3 -m venv "$VENV_DIR"
+# shellcheck disable=SC1091
+source "${VENV_DIR}/bin/activate"
+
+echo "Upgrading pip ..."
+pip install --upgrade pip
+
+echo "Installing Python dependencies from requirements.txt ..."
+pip install --prefer-binary -r "${SCRIPT_DIR}/requirements.txt"
+
+if [ "$BUILD_PYSIMPLE" -eq 1 ]; then
+    echo "Building pysimple (Fortran-Python bindings) ..."
+    # Build SIMPLE first if not already built
+    if [ ! -f "${SCRIPT_DIR}/build/build.ninja" ]; then
+        echo "  Configuring CMake ..."
+        cmake -S "$SCRIPT_DIR" -B"${SCRIPT_DIR}/build" -GNinja \
+            -DCMAKE_BUILD_TYPE=Release -DCMAKE_COLOR_DIAGNOSTICS=ON
+    fi
+    echo "  Building Fortran library ..."
+    cmake --build "${SCRIPT_DIR}/build" --config Release
+
+    echo "  Installing pysimple in editable mode ..."
+    pip install --no-build-isolation -e "$SCRIPT_DIR"
+else
+    echo "Skipping pysimple build (--no-pysimple)."
+fi
+
+echo ""
+echo "Done. Activate with:"
+echo "  source .venv/bin/activate"