diff --git a/python/ray/autoscaler/_private/load_metrics.py b/python/ray/autoscaler/_private/load_metrics.py
index 177fcfaa0d0e..930229aa634f 100644
--- a/python/ray/autoscaler/_private/load_metrics.py
+++ b/python/ray/autoscaler/_private/load_metrics.py
@@ -102,7 +102,6 @@ def update(
         self.static_resources_by_ip[ip] = static_resources
         self.raylet_id_by_ip[ip] = raylet_id
         self.cluster_full_of_actors_detected = cluster_full_of_actors_detected
-        self.ray_nodes_last_used_time_by_ip[ip] = node_last_used_time_s
 
         if not waiting_bundles:
             waiting_bundles = []
@@ -122,6 +121,9 @@ def update(
         self.dynamic_resources_by_ip[ip] = dynamic_resources_update
 
         now = time.time()
+        self.ray_nodes_last_used_time_by_ip[ip] = (
+            node_last_used_time_s if node_last_used_time_s else now
+        )
         self.last_heartbeat_time_by_ip[ip] = now
         self.waiting_bundles = waiting_bundles
         self.infeasible_bundles = infeasible_bundles
diff --git a/python/ray/autoscaler/_private/monitor.py b/python/ray/autoscaler/_private/monitor.py
index e5ce6cc01cda..f9872d9d0202 100644
--- a/python/ray/autoscaler/_private/monitor.py
+++ b/python/ray/autoscaler/_private/monitor.py
@@ -320,7 +320,13 @@ def update_load_metrics(self):
             else:
                 ip = resource_message.node_manager_address
 
-            idle_duration_ms = ray_nodes_idle_duration_ms_by_id[node_id]
+            idle_duration_ms = 0.0
+            if node_id in ray_nodes_idle_duration_ms_by_id:
+                idle_duration_ms = ray_nodes_idle_duration_ms_by_id[node_id]
+            else:
+                logger.warning(
+                    f"node_id {node_id} not found in ray_nodes_idle_duration_ms_by_id"
+                )
 
             self.load_metrics.update(
                 ip,
@@ -331,7 +337,9 @@ def update_load_metrics(self):
                 infeasible_bundles,
                 pending_placement_groups,
                 cluster_full,
-                time.time() - idle_duration_ms / 1000,  # last_used_time
+                time.time()
+                - idle_duration_ms
+                / 1000,  # node_last_used_time_s = now - idle_duration
             )
         if self.readonly_config:
             self.readonly_config["available_node_types"].update(mirror_node_types)