diff --git a/CLAUDE.md b/CLAUDE.md
index d1eb61ef..24fe49df 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -258,12 +258,14 @@ User submits QSO → enqueue_for_qso() → weather/hrrr/terrain/iemre workers
 3. Safety net: `PropagationPruneWorker` every 15 min, deletes files older than 3h
 4. `GridCachePruneWorker` every 15 min for in-memory/valkey grid cache
 
-**Known cleanup gaps:**
-- Building footprint tiles (`/data/buildings/`) — no expiration, no cleanup
-- Canopy tiles (`/data/canopy/`) — no expiration, no cleanup
-- Orphaned `.tmp` files from crashed writes — no periodic sweep
-- HRDPS companion files (`.hrdps.prop`, `weather_scalars/{iso}.hrdps/`) — prune parity with HRRR needs verification
-- Empty parent directories after prune — no cleanup of empty dirs
+**Known cleanup gaps (confirmed):**
+- Building footprint tiles (`/data/buildings/`) — no cleanup, no mtime-based expiry
+- Canopy tiles (`/data/canopy/` + staging COGs) — no cleanup
+- `.hrdps.prop` score files — `parse_valid_time` regex (`~r/^(.+)\.(?:prop|ntms)$/`) captures `iso.hrdps` which fails `DateTime.from_iso8601`; silently excluded from all prune + list operations
+- `ScalarFile.prune_older_than` — defined but **never called** from `Propagation.prune_old_scores` (only Scores + Profiles called)
+- HRDPS scalar dirs (`weather_scalars/{iso}.hrdps/`) — `list_valid_time_dirs` uses `DateTime.from_iso8601` directly which fails on `iso.hrdps` suffix; invisible to prune
+- Orphaned `.tmp.*` files — atomic write (write→rename) leaves tmp files on crash; no scavenging in any Elixir or Rust writer (only `scores_file.rs` cleans its tmp on explicit rename error)
+- Empty parent dirs after prune — no `rmdir` after individual file deletes in scores/profiles dirs
 
 ### Operational gotchas
 - **`kubectl exec deploy/prop` may route to the backfill pod**: the `prop` and `prop-backfill` deployments share label selectors, so `deploy/prop` can attach to either. When diagnosing cron / leader-only behavior, identify the hot pod by name first: `kubectl -n prop get pods -o name | grep -E '^pod/prop-[a-z0-9]+-[a-z0-9]+$' | head -1`. The backfill pod has `PROP_ROLE=backfill` and `peer: false` on its Oban; running RPC there is misleading because plugins gated on leader (Cron, etc.) appear inert by design.
diff --git a/lib/microwaveprop/buildings/ms_footprints.ex b/lib/microwaveprop/buildings/ms_footprints.ex
index 887022fd..57d86a18 100644
--- a/lib/microwaveprop/buildings/ms_footprints.ex
+++ b/lib/microwaveprop/buildings/ms_footprints.ex
@@ -152,4 +152,31 @@ defmodule Microwaveprop.Buildings.MsFootprints do
         end
     end
   end
+
+  @doc """
+  Delete building cache files whose mtime is older than `cutoff`.
+  Returns the number of files deleted.
+  """
+  @spec prune_older_than(DateTime.t()) :: integer()
+  def prune_older_than(%DateTime{} = cutoff) do
+    cutoff_unix = DateTime.to_unix(cutoff)
+
+    case File.ls(cache_dir()) do
+      {:ok, files} -> Enum.reduce(files, 0, &prune_file(&1, &2, cutoff_unix))
+      _ -> 0
+    end
+  end
+
+  defp prune_file(file, acc, cutoff_unix) do
+    path = Path.join(cache_dir(), file)
+    stat = File.stat!(path)
+    mtime_unix = stat.mtime |> NaiveDateTime.from_erl!() |> DateTime.from_naive!("Etc/UTC") |> DateTime.to_unix()
+
+    if mtime_unix < cutoff_unix do
+      _ = File.rm(path)
+      acc + 1
+    else
+      acc
+    end
+  end
 end
diff --git a/lib/microwaveprop/canopy.ex b/lib/microwaveprop/canopy.ex
index f17a7415..f6a77963 100644
--- a/lib/microwaveprop/canopy.ex
+++ b/lib/microwaveprop/canopy.ex
@@ -94,4 +94,64 @@ defmodule Microwaveprop.Canopy do
   defp default_dir do
     Application.get_env(:microwaveprop, :canopy_tiles_dir, "/data/canopy")
   end
+
+  @doc """
+  Delete canopy tile cache files older than `cutoff` (by mtime).
+  Cleans up both tile cache and staging COG files.
+  Returns the number of files deleted.
+  """
+  @spec prune_older_than(DateTime.t()) :: number()
+  def prune_older_than(%DateTime{} = cutoff) do
+    cutoff_unix = DateTime.to_unix(cutoff)
+
+    canopy_dir = Application.get_env(:microwaveprop, :canopy_tiles_dir, "/data/canopy")
+    staging_dir = Application.get_env(:microwaveprop, :canopy_staging_dir, "/data/canopy/staging")
+
+    tiles_deleted = prune_dir(canopy_dir, cutoff_unix)
+    staging_deleted = prune_dir(staging_dir, cutoff_unix)
+
+    _ = maybe_rmdir_empty(staging_dir, staging_deleted)
+
+    tiles_deleted + staging_deleted
+  end
+
+  defp prune_dir(dir, cutoff_unix) do
+    case File.ls(dir) do
+      {:ok, files} -> Enum.reduce(files, 0, &prune_file(dir, &1, &2, cutoff_unix))
+      _ -> 0
+    end
+  end
+
+  defp prune_file(dir, file, acc, cutoff_unix) do
+    path = Path.join(dir, file)
+
+    case File.stat(path) do
+      {:ok, stat} ->
+        mtime_unix =
+          stat.mtime |> NaiveDateTime.from_erl!() |> DateTime.from_naive!("Etc/UTC") |> DateTime.to_unix()
+
+        if mtime_unix < cutoff_unix do
+          _ = do_delete(path)
+          acc + 1
+        else
+          acc
+        end
+
+      _ ->
+        acc
+    end
+  end
+
+  defp do_delete(path) do
+    _ = if File.dir?(path), do: File.rm_rf(path), else: File.rm(path)
+  end
+
+  defp maybe_rmdir_empty(_dir, 0), do: :ok
+
+  defp maybe_rmdir_empty(dir, _deleted) do
+    case File.ls(dir) do
+      {:ok, []} -> File.rmdir(dir)
+      _ -> :ok
+    end
+  end
 end
diff --git a/lib/microwaveprop/propagation.ex b/lib/microwaveprop/propagation.ex
index a338211c..81dc35b0 100644
--- a/lib/microwaveprop/propagation.ex
+++ b/lib/microwaveprop/propagation.ex
@@ -11,6 +11,7 @@ defmodule Microwaveprop.Propagation do
   alias Microwaveprop.Propagation.Scorer
   alias Microwaveprop.Propagation.ScoresFile
   alias Microwaveprop.Repo
+  alias Microwaveprop.Weather.ScalarFile
   alias Microwaveprop.Weather.SoundingParams
 
   require Logger
@@ -234,17 +235,44 @@ defmodule Microwaveprop.Propagation do
     cutoff = DateTime.add(DateTime.utc_now(), -3, :hour)
     file_deleted = ScoresFile.prune_older_than(cutoff)
     profiles_deleted = ProfilesFile.prune_older_than(cutoff)
+    scalar_deleted = ScalarFile.prune_older_than(cutoff)
 
-    if file_deleted + profiles_deleted > 0 do
+    total = file_deleted + profiles_deleted + scalar_deleted
+
+    if total > 0 do
       Logger.info(
         "PropagationScores: pruned #{file_deleted} old score files + " <>
-          "#{profiles_deleted} profile files (before #{cutoff})"
+          "#{profiles_deleted} profile files + #{scalar_deleted} scalar dirs " <>
+          "(before #{cutoff})"
       )
     end
 
+    # Sweep orphaned .tmp.* files left by crashed atomic-write processes
+    tmp_deleted =
+      Enum.reduce([ScoresFile.base_dir(), ProfilesFile.base_dir(), ScalarFile.base_dir()], 0, &sweep_tmp_dir/2)
+
+    if tmp_deleted > 0 do
+      Logger.info("PropagationScores: swept #{tmp_deleted} orphaned .tmp files")
+    end
+
     :ok
   end
 
+  defp sweep_tmp_dir(dir, acc) do
+    case File.ls(dir) do
+      {:ok, entries} ->
+        entries
+        |> Enum.filter(&String.contains?(&1, ".tmp."))
+        |> Enum.reduce(acc, fn entry, acc ->
+          _ = File.rm_rf(Path.join(dir, entry))
+          acc + 1
+        end)
+
+      _ ->
+        acc
+    end
+  end
+
   @doc """
   Returns distinct valid_times for a band, ordered ascending. Always
   reads from the on-disk `ScoresFile` store — the `ScoreCache` only
diff --git a/lib/microwaveprop/propagation/scores_file.ex b/lib/microwaveprop/propagation/scores_file.ex
index 5b165102..874c151d 100644
--- a/lib/microwaveprop/propagation/scores_file.ex
+++ b/lib/microwaveprop/propagation/scores_file.ex
@@ -513,7 +513,7 @@ defmodule Microwaveprop.Propagation.ScoresFile do
   end
 
   defp parse_valid_time_dt(filename) do
-    with [_, iso] <- Regex.run(~r/^(.+)\.(?:prop|ntms)$/, filename),
+    with [_, iso] <- Regex.run(~r/^(.+)\.(?:hrdps\.prop|prop|ntms)$/, filename),
          {:ok, dt, _} <- DateTime.from_iso8601(iso) do
       dt
     else
@@ -548,7 +548,7 @@ defmodule Microwaveprop.Propagation.ScoresFile do
   end
 
   defp parse_valid_time(filename) do
-    with [_, iso] <- Regex.run(~r/^(.+)\.(?:prop|ntms)$/, filename),
+    with [_, iso] <- Regex.run(~r/^(.+)\.(?:hrdps\.prop|prop|ntms)$/, filename),
          {:ok, dt, _} <- DateTime.from_iso8601(iso) do
       DateTime.to_unix(dt)
     else
diff --git a/lib/microwaveprop/weather/scalar_file.ex b/lib/microwaveprop/weather/scalar_file.ex
index 8711cef9..1290994a 100644
--- a/lib/microwaveprop/weather/scalar_file.ex
+++ b/lib/microwaveprop/weather/scalar_file.ex
@@ -509,7 +509,8 @@ defmodule Microwaveprop.Weather.ScalarFile do
     case File.ls(base) do
       {:ok, entries} ->
         for entry <- entries,
-            {:ok, dt, _} <- [DateTime.from_iso8601(entry)],
+            iso = String.replace_suffix(entry, ".hrdps", ""),
+            {:ok, dt, _} <- [DateTime.from_iso8601(iso)],
             do: {Path.join(base, entry), dt}
 
       _ ->
diff --git a/lib/microwaveprop/workers/propagation_prune_worker.ex b/lib/microwaveprop/workers/propagation_prune_worker.ex
index 48306c8b..130e757f 100644
--- a/lib/microwaveprop/workers/propagation_prune_worker.ex
+++ b/lib/microwaveprop/workers/propagation_prune_worker.ex
@@ -18,11 +18,28 @@ defmodule Microwaveprop.Workers.PropagationPruneWorker do
     max_attempts: 3,
     unique: [period: 300, states: :incomplete]
 
+  alias Microwaveprop.Buildings.MsFootprints
+  alias Microwaveprop.Canopy
   alias Microwaveprop.Propagation
 
+  require Logger
+
   @impl Oban.Pro.Worker
   def process(%Oban.Job{}) do
     Propagation.prune_old_scores()
+
+    cutoff_30d = DateTime.add(DateTime.utc_now(), -30, :day)
+    buildings_deleted = MsFootprints.prune_older_than(cutoff_30d)
+    canopy_deleted = Canopy.prune_older_than(cutoff_30d)
+
+    if buildings_deleted > 0 do
+      Logger.info("MsFootprints: pruned #{buildings_deleted} cached tile files older than #{cutoff_30d}")
+    end
+
+    if canopy_deleted > 0 do
+      Logger.info("Canopy: pruned #{canopy_deleted} cached tile/staging files older than #{cutoff_30d}")
+    end
+
     :ok
   end
 end