diff --git a/lib/microwaveprop/application.ex b/lib/microwaveprop/application.ex
index ee087d30..1f5beee5 100644
--- a/lib/microwaveprop/application.ex
+++ b/lib/microwaveprop/application.ex
@@ -35,6 +35,11 @@ defmodule Microwaveprop.Application do
     # Run migrations after Repo is started
     Microwaveprop.Release.migrate()
 
+    # Warm GridCache from the latest persisted ProfilesFile so /weather
+    # has data immediately after a pod restart. Runs after the GridCache
+    # GenServer is up (it's in `children` above).
+    Microwaveprop.Weather.warm_grid_cache_from_latest_profile()
+
     # Load ML model in dev/test only (Nx/Axon not compiled for prod)
     if Application.get_env(:microwaveprop, :load_ml_model, false) do
       Microwaveprop.Propagation.load_ml_model()
diff --git a/lib/microwaveprop/propagation/profiles_file.ex b/lib/microwaveprop/propagation/profiles_file.ex
index 850be117..23986d5c 100644
--- a/lib/microwaveprop/propagation/profiles_file.ex
+++ b/lib/microwaveprop/propagation/profiles_file.ex
@@ -62,6 +62,20 @@ defmodule Microwaveprop.Propagation.ProfilesFile do
     :ok
   end
 
+  @doc """
+  Read the full persisted grid_data for `valid_time`. Returns
+  `{:ok, %{{lat, lon} => profile}}` or `{:error, :enoent}` if the file
+  doesn't exist. Used by `Microwaveprop.Weather` to warm `GridCache`
+  on pod startup without touching the database.
+  """
+  @spec read(DateTime.t()) :: {:ok, %{{float(), float()} => map()}} | {:error, :enoent}
+  def read(%DateTime{} = valid_time) do
+    case File.read(path_for(valid_time)) do
+      {:ok, binary} -> {:ok, :erlang.binary_to_term(binary, [:safe])}
+      {:error, _} -> {:error, :enoent}
+    end
+  end
+
   @doc """
   Read a single profile for `(valid_time, lat, lon)`. Returns `nil` if
   the file is missing or the point has no profile. Input lat/lon are
@@ -69,13 +83,10 @@ defmodule Microwaveprop.Propagation.ProfilesFile do
   """
   @spec read_point(DateTime.t(), float(), float()) :: map() | nil
   def read_point(%DateTime{} = valid_time, lat, lon) do
-    case File.read(path_for(valid_time)) do
-      {:ok, binary} ->
+    case read(valid_time) do
+      {:ok, grid_data} ->
         {snapped_lat, snapped_lon} = snap(lat, lon)
-
-        binary
-        |> :erlang.binary_to_term([:safe])
-        |> Map.get({snapped_lat, snapped_lon})
+        Map.get(grid_data, {snapped_lat, snapped_lon})
 
       {:error, _} ->
         nil
diff --git a/lib/microwaveprop/weather.ex b/lib/microwaveprop/weather.ex
index 90289b76..47686609 100644
--- a/lib/microwaveprop/weather.ex
+++ b/lib/microwaveprop/weather.ex
@@ -3,6 +3,7 @@ defmodule Microwaveprop.Weather do
 
   import Ecto.Query
 
+  alias Microwaveprop.Propagation.ProfilesFile
   alias Microwaveprop.Repo
   alias Microwaveprop.Weather.Era5Profile
   alias Microwaveprop.Weather.GridCache
@@ -361,20 +362,26 @@ defmodule Microwaveprop.Weather do
 
   @spec latest_grid_valid_time() :: DateTime.t() | nil
   def latest_grid_valid_time do
-    case GridCache.latest_valid_time() do
-      %DateTime{} = vt ->
-        vt
-
-      nil ->
-        Repo.one(
-          from(h in HrrrProfile,
-            where: h.is_grid_point == true,
-            select: max(h.valid_time)
-          )
-        )
+    cond do
+      vt = GridCache.latest_valid_time() -> vt
+      vt = ProfilesFile.latest_valid_time() -> vt
+      true -> latest_grid_valid_time_from_db()
     end
   end
 
+  # Last-resort fallback for historical data sitting in the legacy
+  # hrrr_profiles table. PropagationGridWorker no longer writes
+  # grid-point rows there, so in steady state this returns nil and
+  # the ProfilesFile fallback above is the real source of truth.
+  defp latest_grid_valid_time_from_db do
+    Repo.one(
+      from(h in HrrrProfile,
+        where: h.is_grid_point == true,
+        select: max(h.valid_time)
+      )
+    )
+  end
+
   @doc """
   Cache-only read for the /weather LiveView mount hot path. Returns whatever
   is in `GridCache` for the latest valid_time and fires a deduped background
@@ -420,13 +427,24 @@ defmodule Microwaveprop.Weather do
             rows
 
           :miss ->
-            full = load_weather_grid_from_db(latest_vt)
+            full = load_grid_rows_for(latest_vt)
             GridCache.put(latest_vt, full)
             filter_weather_bounds(full, bounds)
         end
     end
   end
 
+  # Build derived GridCache rows for a valid_time from whichever
+  # source has data: the persisted ProfilesFile first (hot path in
+  # steady state), then the legacy hrrr_profiles table (historical
+  # data only).
+  defp load_grid_rows_for(valid_time) do
+    case ProfilesFile.read(valid_time) do
+      {:ok, grid_data} -> build_grid_cache_rows(grid_data, valid_time)
+      {:error, _} -> load_weather_grid_from_db(valid_time)
+    end
+  end
+
   defp filter_weather_bounds(rows, nil), do: rows
 
   defp filter_weather_bounds(rows, %{"south" => s, "north" => n, "west" => w, "east" => e}) do
@@ -495,11 +513,38 @@ defmodule Microwaveprop.Weather do
   """
   @spec warm_grid_cache_and_broadcast(DateTime.t()) :: :ok
   def warm_grid_cache_and_broadcast(valid_time) do
-    rows = load_weather_grid_from_db(valid_time)
+    rows = load_grid_rows_for(valid_time)
     GridCache.broadcast_put(valid_time, rows)
     :ok
   end
 
+  @doc """
+  Warm the local `GridCache` from the latest persisted `ProfilesFile`
+  on pod startup. Makes `/weather` usable immediately after a deploy
+  instead of waiting for the next hourly PropagationGridWorker run.
+  Local put only — every node reads the same NFS mount so no need to
+  broadcast.
+  """
+  @spec warm_grid_cache_from_latest_profile() :: :ok
+  def warm_grid_cache_from_latest_profile do
+    case ProfilesFile.latest_valid_time() do
+      nil ->
+        :ok
+
+      valid_time ->
+        try do
+          rows = load_grid_rows_for(valid_time)
+          GridCache.put(valid_time, rows)
+          Logger.info("Weather: warmed GridCache from ProfilesFile for #{valid_time} (#{length(rows)} rows)")
+        rescue
+          e ->
+            Logger.warning("Weather: ProfilesFile warm failed: #{inspect(e)}")
+        end
+
+        :ok
+    end
+  end
+
   @doc """
   Build derived weather grid cache rows directly from the in-memory HRRR
   `grid_data` that `PropagationGridWorker` already has after fetching a
@@ -566,8 +611,30 @@ defmodule Microwaveprop.Weather do
     snapped_lon = Float.round(Float.round(lon / step) * step, 3)
 
     case GridCache.fetch_point(valid_time, snapped_lat, snapped_lon) do
-      {:ok, row} -> row
-      :miss -> weather_point_detail_from_db(valid_time, snapped_lat, snapped_lon)
+      {:ok, row} ->
+        row
+
+      :miss ->
+        case weather_point_detail_from_profiles(valid_time, snapped_lat, snapped_lon) do
+          nil -> weather_point_detail_from_db(valid_time, snapped_lat, snapped_lon)
+          row -> row
+        end
+    end
+  end
+
+  # Derive a single GridCache-shaped row from a persisted ProfilesFile
+  # entry for `(valid_time, lat, lon)`. Returns nil when the file
+  # doesn't exist or the point has no profile.
+  defp weather_point_detail_from_profiles(valid_time, snapped_lat, snapped_lon) do
+    case ProfilesFile.read_point(valid_time, snapped_lat, snapped_lon) do
+      nil ->
+        nil
+
+      profile ->
+        case build_grid_cache_rows(%{{snapped_lat, snapped_lon} => profile}, valid_time) do
+          [row] -> row
+          _ -> nil
+        end
     end
   end
 
diff --git a/lib/microwaveprop/workers/propagation_grid_worker.ex b/lib/microwaveprop/workers/propagation_grid_worker.ex
index 3683803d..40fe293b 100644
--- a/lib/microwaveprop/workers/propagation_grid_worker.ex
+++ b/lib/microwaveprop/workers/propagation_grid_worker.ex
@@ -198,13 +198,12 @@ defmodule Microwaveprop.Workers.PropagationGridWorker do
 
         :erlang.garbage_collect()
 
-        # Persist the fully-enriched f00 grid_data so point_detail can
-        # rebuild the factor breakdown for a clicked cell by re-running
-        # the scorer against the stored profile. Forecast hours skip
-        # factors in compute_scores, so we skip them here too.
-        if forecast_hour == 0 do
-          persist_f00_profiles(grid_data, valid_time)
-        end
+        # Persist the fully-enriched grid_data for every forecast hour
+        # so (a) /weather can show forecast-hour data after a pod
+        # restart and (b) point_detail can rebuild the factor
+        # breakdown for a clicked cell at any forecast hour by
+        # re-running the scorer against the stored profile.
+        persist_profiles(grid_data, valid_time)
 
         # Build weather cache rows from in-memory grid_data — avoids the ~20s
         # JSONB round trip that was crashing the worker before f01–f18 could run.
@@ -236,7 +235,7 @@ defmodule Microwaveprop.Workers.PropagationGridWorker do
     end
   end
 
-  defp persist_f00_profiles(grid_data, valid_time) do
+  defp persist_profiles(grid_data, valid_time) do
     timed("profiles", fn ->
       try do
         ProfilesFile.write!(valid_time, grid_data)
diff --git a/test/microwaveprop/propagation/profiles_file_test.exs b/test/microwaveprop/propagation/profiles_file_test.exs
index f15937a5..14bb8270 100644
--- a/test/microwaveprop/propagation/profiles_file_test.exs
+++ b/test/microwaveprop/propagation/profiles_file_test.exs
@@ -37,6 +37,39 @@ defmodule Microwaveprop.Propagation.ProfilesFileTest do
     end
   end
 
+  describe "read/1" do
+    test "returns the full grid_data map round-tripped through ETF" do
+      valid_time = ~U[2026-04-14 18:00:00Z]
+
+      grid_data = %{
+        {32.75, -97.125} => %{surface_temp_c: 25.0, surface_dewpoint_c: 15.0},
+        {33.0, -97.0} => %{surface_temp_c: 26.0}
+      }
+
+      ProfilesFile.write!(valid_time, grid_data)
+
+      assert {:ok, round_tripped} = ProfilesFile.read(valid_time)
+      assert round_tripped[{32.75, -97.125}][:surface_temp_c] == 25.0
+      assert round_tripped[{33.0, -97.0}][:surface_temp_c] == 26.0
+    end
+
+    test "returns :enoent when no file exists" do
+      assert ProfilesFile.read(~U[2026-04-14 18:00:00Z]) == {:error, :enoent}
+    end
+  end
+
+  describe "latest_valid_time/0" do
+    test "returns the most recent persisted valid_time" do
+      assert ProfilesFile.latest_valid_time() == nil
+
+      for vt <- [~U[2026-04-14 10:00:00Z], ~U[2026-04-14 18:00:00Z], ~U[2026-04-14 14:00:00Z]] do
+        ProfilesFile.write!(vt, %{{25.0, -125.0} => %{surface_temp_c: 1.0}})
+      end
+
+      assert ProfilesFile.latest_valid_time() == ~U[2026-04-14 18:00:00Z]
+    end
+  end
+
   describe "write!/2 + read_point/3" do
     test "round-trips a point and snaps lat/lon to the 0.125° grid" do
       valid_time = ~U[2026-04-14 18:00:00Z]
diff --git a/test/microwaveprop/weather_grid_test.exs b/test/microwaveprop/weather_grid_test.exs
index d409f949..ec6ebbc1 100644
--- a/test/microwaveprop/weather_grid_test.exs
+++ b/test/microwaveprop/weather_grid_test.exs
@@ -1,6 +1,7 @@
 defmodule Microwaveprop.WeatherGridTest do
   use Microwaveprop.DataCase, async: false
 
+  alias Microwaveprop.Propagation.ProfilesFile
   alias Microwaveprop.Repo
   alias Microwaveprop.Weather
   alias Microwaveprop.Weather.GridCache
@@ -359,6 +360,33 @@ defmodule Microwaveprop.WeatherGridTest do
       assert Weather.weather_point_detail(32.15, -97.40, now) == nil
     end
 
+    test "falls back to ProfilesFile when GridCache is cold and DB has no grid points" do
+      now = DateTime.truncate(DateTime.utc_now(), :second)
+
+      grid_data = %{
+        {32.125, -97.375} => %{
+          surface_temp_c: 25.0,
+          surface_dewpoint_c: 18.0,
+          surface_pressure_mb: 1013.0,
+          hpbl_m: 500.0,
+          pwat_mm: 30.0,
+          profile: [
+            %{"pres" => 1000.0, "tmpc" => 25.0, "dwpc" => 18.0, "hght" => 100.0},
+            %{"pres" => 850.0, "tmpc" => 15.0, "dwpc" => 10.0, "hght" => 1500.0},
+            %{"pres" => 500.0, "tmpc" => -15.0, "dwpc" => -25.0, "hght" => 5600.0}
+          ]
+        }
+      }
+
+      ProfilesFile.write!(now, grid_data)
+
+      result = Weather.weather_point_detail(32.15, -97.40, now)
+
+      assert result.lat == 32.125
+      assert result.temperature == 25.0
+      assert result.surface_pressure_mb == 1013.0
+    end
+
     test "includes derived upper-air fields and strips raw profile data" do
       now = DateTime.truncate(DateTime.utc_now(), :second)
 
@@ -403,6 +431,48 @@ defmodule Microwaveprop.WeatherGridTest do
     end
   end
 
+  describe "latest_grid_valid_time/0 + ProfilesFile fallback" do
+    test "uses ProfilesFile.latest_valid_time when GridCache and DB are both empty" do
+      vt = ~U[2026-04-14 18:00:00Z]
+
+      ProfilesFile.write!(vt, %{
+        {32.125, -97.375} => %{surface_temp_c: 20.0, surface_dewpoint_c: 15.0}
+      })
+
+      assert Weather.latest_grid_valid_time() == vt
+    end
+  end
+
+  describe "load_weather_grid/1 + ProfilesFile fallback" do
+    test "returns derived rows from ProfilesFile when GridCache is empty" do
+      vt = ~U[2026-04-14 18:00:00Z]
+
+      ProfilesFile.write!(vt, %{
+        {32.125, -97.375} => %{
+          surface_temp_c: 25.0,
+          surface_dewpoint_c: 18.0,
+          surface_pressure_mb: 1013.0,
+          hpbl_m: 500.0,
+          pwat_mm: 30.0
+        },
+        {32.250, -97.375} => %{
+          surface_temp_c: 26.0,
+          surface_dewpoint_c: 19.0,
+          surface_pressure_mb: 1012.0,
+          hpbl_m: 600.0,
+          pwat_mm: 32.0
+        }
+      })
+
+      bounds = %{"south" => 32.0, "north" => 33.0, "west" => -98.0, "east" => -97.0}
+      rows = Weather.load_weather_grid(bounds)
+
+      assert length(rows) == 2
+      assert Enum.any?(rows, &(&1.temperature == 25.0))
+      assert Enum.any?(rows, &(&1.temperature == 26.0))
+    end
+  end
+
   defp insert_hrrr_profile(attrs) do
     now = DateTime.truncate(DateTime.utc_now(), :second)
 
diff --git a/test/support/conn_case.ex b/test/support/conn_case.ex
index 791e7121..f6b2b828 100644
--- a/test/support/conn_case.ex
+++ b/test/support/conn_case.ex
@@ -37,6 +37,9 @@ defmodule MicrowavepropWeb.ConnCase do
 
   setup tags do
     Microwaveprop.DataCase.setup_sandbox(tags)
+    Microwaveprop.DataCase.reset_score_files()
+    Microwaveprop.Weather.GridCache.clear()
+    Microwaveprop.Propagation.ScoreCache.clear()
     {:ok, conn: Phoenix.ConnTest.build_conn()}
   end