diff --git a/.env.example b/.env.example
index 18d65f54..d678ff3b 100644
--- a/.env.example
+++ b/.env.example
@@ -100,6 +100,7 @@ GROQ_API_KEY=
 POLYWEATHER_GROQ_COMMENTARY_MODEL=openai/gpt-oss-20b
 POLYWEATHER_GROQ_COMMENTARY_TIMEOUT_SEC=8
 POLYWEATHER_GROQ_COMMENTARY_CACHE_TTL_SEC=1800
+POLYWEATHER_PREWARM_CITIES=ankara,istanbul,shanghai,beijing,shenzhen,wuhan,chengdu,chongqing,hong kong,taipei,singapore,tokyo,seoul,busan,london,paris,madrid
 
 # Weekly reward / leaderboard
 POLYWEATHER_WEEKLY_REWARD_ENABLED=true
diff --git a/docs/CONFIGURATION_ZH.md b/docs/CONFIGURATION_ZH.md
index 3132761f..6ee3c888 100644
--- a/docs/CONFIGURATION_ZH.md
+++ b/docs/CONFIGURATION_ZH.md
@@ -146,6 +146,14 @@ PolyWeather 的环境变量很多，但不是所有变量都属于同一层级
 - 先用默认值
 - 出现性能或运维问题时再调
 
+当前默认预热名单优先覆盖：
+
+- 亚洲：Shanghai、Beijing、Shenzhen、Wuhan、Chengdu、Chongqing、Hong Kong、Taipei、Singapore、Tokyo、Seoul、Busan
+- 中东：Ankara、Istanbul
+- 欧洲：London、Paris、Madrid
+
+默认不再包含美国城市；如果线上 `.env` 已手动设置 `POLYWEATHER_PREWARM_CITIES`，则会以你的显式配置为准。
+
 ### 4.4 L4：敏感项
 
 这些变量不应写进公开文档截图，也不应提交到仓库。
@@ -285,7 +293,7 @@ POLYWEATHER_GROQ_COMMENTARY_CACHE_TTL_SEC=1800
 POLYWEATHER_DASHBOARD_PREWARM_ENABLED=true
 POLYWEATHER_PREWARM_INTERVAL_SEC=300
 POLYWEATHER_PREWARM_JITTER_SEC=20
-POLYWEATHER_PREWARM_CITIES=ankara,istanbul,shanghai,beijing,shenzhen,wuhan,chengdu,chongqing,hong kong,taipei,london,paris,new york,los angeles
+POLYWEATHER_PREWARM_CITIES=ankara,istanbul,shanghai,beijing,shenzhen,wuhan,chengdu,chongqing,hong kong,taipei,singapore,tokyo,seoul,busan,london,paris,madrid
 POLYWEATHER_PREWARM_INCLUDE_DETAIL=true
 POLYWEATHER_PREWARM_INCLUDE_MARKET=true
 POLYWEATHER_PREWARM_FORCE_REFRESH=false
diff --git a/src/utils/prewarm_dashboard.py b/src/utils/prewarm_dashboard.py
index c1458612..f023ee79 100644
--- a/src/utils/prewarm_dashboard.py
+++ b/src/utils/prewarm_dashboard.py
@@ -25,10 +25,13 @@ DEFAULT_CITIES = [
     "chongqing",
     "hong kong",
     "taipei",
+    "singapore",
+    "tokyo",
+    "seoul",
+    "busan",
     "london",
     "paris",
-    "new york",
-    "los angeles",
+    "madrid",
 ]
 
 _RUNTIME_LOCK = threading.Lock()
diff --git a/web/routes.py b/web/routes.py
index a94df910..1f534a9c 100644
--- a/web/routes.py
+++ b/web/routes.py
@@ -79,10 +79,13 @@ DEFAULT_PREWARM_CITIES = [
     "chongqing",
     "hong kong",
     "taipei",
+    "singapore",
+    "tokyo",
+    "seoul",
+    "busan",
     "london",
     "paris",
-    "new york",
-    "los angeles",
+    "madrid",
 ]