diff --git a/.sampo/changesets/forthright-seer-otso.md b/.sampo/changesets/forthright-seer-otso.md
new file mode 100644
index 00000000..bcaf975e
--- /dev/null
+++ b/.sampo/changesets/forthright-seer-otso.md
@@ -0,0 +1,5 @@
+---
+pypi/posthog: patch
+---
+
+Add warning log for local flag evaluation cold start
diff --git a/posthog/client.py b/posthog/client.py
index 4de95581..0157b1df 100644
--- a/posthog/client.py
+++ b/posthog/client.py
@@ -1620,7 +1620,13 @@ def _get_feature_flag_result(
                 self.flag_cache.set_cached_flag(
                     distinct_id, key, flag_result, self.flag_definition_version
                 )
-        elif not only_evaluate_locally:
+        elif only_evaluate_locally:
+            if self.feature_flags is None:
+                self.log.warning(
+                    "[FEATURE FLAGS] Local evaluation called but feature flag definitions are not loaded yet. "
+                    "Returning None. You can call load_feature_flags() to load flags explicitly."
+                )
+        else:
             try:
                 flag_details, request_id, evaluated_at, errors_while_computing = (
                     self._get_feature_flag_details_from_server(