diff --git a/lib/microwaveprop/workers/hrrr_fetch_worker.ex b/lib/microwaveprop/workers/hrrr_fetch_worker.ex
index 783f50f1..1b5bcb35 100644
--- a/lib/microwaveprop/workers/hrrr_fetch_worker.ex
+++ b/lib/microwaveprop/workers/hrrr_fetch_worker.ex
@@ -47,11 +47,21 @@ defmodule Microwaveprop.Workers.HrrrFetchWorker do
           :ok
 
         {:error, reason} ->
-          {:error, reason}
+          if permanent_failure?(reason) do
+            {:cancel, reason}
+          else
+            {:error, reason}
+          end
       end
     end
   end
 
+  # 404 means the HRRR data doesn't exist (pre-2014, etc.) — will never succeed
+  defp permanent_failure?("HRRR idx HTTP 404"), do: true
+  defp permanent_failure?("HRRR grib HTTP 404"), do: true
+  defp permanent_failure?(:outside_grid), do: true
+  defp permanent_failure?(_), do: false
+
   defp maybe_add_derived_params(attrs, nil), do: attrs
 
   defp maybe_add_derived_params(attrs, params) do
diff --git a/test/microwaveprop/workers/hrrr_fetch_worker_test.exs b/test/microwaveprop/workers/hrrr_fetch_worker_test.exs
index 7763aff4..20aa6ea1 100644
--- a/test/microwaveprop/workers/hrrr_fetch_worker_test.exs
+++ b/test/microwaveprop/workers/hrrr_fetch_worker_test.exs
@@ -89,6 +89,24 @@ defmodule Microwaveprop.Workers.HrrrFetchWorkerTest do
     end
   end
 
+  describe "permanent_failure?/1" do
+    test "cancels on 404 idx" do
+      job = %Oban.Job{
+        args: %{
+          "lat" => 32.90,
+          "lon" => -97.04,
+          "valid_time" => "1995-06-15T12:00:00Z"
+        }
+      }
+
+      Req.Test.stub(Microwaveprop.Weather.HrrrClient, fn conn ->
+        Plug.Conn.send_resp(conn, 404, "not found")
+      end)
+
+      assert {:cancel, "HRRR idx HTTP 404"} = HrrrFetchWorker.perform(job)
+    end
+  end
+
   defp build_profile_attrs(lat, lon, valid_time, client_result) do
     %{
       valid_time: valid_time,