diff --git a/flepimop/gempyor_pkg/src/gempyor/utils.py b/flepimop/gempyor_pkg/src/gempyor/utils.py
index 98c54a1f1..85820d5b2 100644
--- a/flepimop/gempyor_pkg/src/gempyor/utils.py
+++ b/flepimop/gempyor_pkg/src/gempyor/utils.py
@@ -13,6 +13,7 @@
 from botocore.exceptions import ClientError
 import confuse
 import numpy as np
+import numpy.typing as npt
 import pandas as pd
 import pyarrow as pa
 import scipy.stats
@@ -392,16 +393,44 @@ def list_filenames(
     return files
 
 
-def rolling_mean_pad(data, window):
+def rolling_mean_pad(
+    data: npt.NDArray[np.number],
+    window: int,
+) -> npt.NDArray[np.number]:
     """
-    Calculates rolling mean with centered window and pads the edges.
+    Calculates the column-wise rolling mean with centered window.
 
     Args:
-        data: A NumPy array !!! shape must be (n_days, nsubpops).
+        data: A two dimensional numpy array, typically the row dimension is time and the
+            column dimension is subpop.
         window: The window size for the rolling mean.
 
     Returns:
-        A NumPy array with the padded rolling mean (n_days, nsubpops).
+        A two dimensional numpy array that is the same shape as `data`.
+
+    Examples:
+        Below is a brief set of examples showcasing how to smooth a metric, like
+        hospitalizations, using this function.
+
+        >>> import numpy as np
+        >>> from gempyor.utils import rolling_mean_pad
+        >>> hospitalizations = np.arange(1., 29.).reshape((7, 4))
+        >>> hospitalizations
+        array([[ 1.,  2.,  3.,  4.],
+            [ 5.,  6.,  7.,  8.],
+            [ 9., 10., 11., 12.],
+            [13., 14., 15., 16.],
+            [17., 18., 19., 20.],
+            [21., 22., 23., 24.],
+            [25., 26., 27., 28.]])
+        >>> rolling_mean_pad(hospitalizations, 5)
+        array([[ 3.4,  4.4,  5.4,  6.4],
+            [ 5.8,  6.8,  7.8,  8.8],
+            [ 9. , 10. , 11. , 12. ],
+            [13. , 14. , 15. , 16. ],
+            [17. , 18. , 19. , 20. ],
+            [20.2, 21.2, 22.2, 23.2],
+            [22.6, 23.6, 24.6, 25.6]])
     """
     padding_size = (window - 1) // 2
     padded_data = np.pad(data, ((padding_size, padding_size), (0, 0)), mode="edge")