diff --git a/tests/test_web_observability.py b/tests/test_web_observability.py
index 5ec78087..cb5a19be 100644
--- a/tests/test_web_observability.py
+++ b/tests/test_web_observability.py
@@ -387,8 +387,9 @@ def test_city_ai_stream_request_only_asks_provider_for_observation_read():
     assert request_payload["stream"] is True
     assert request_payload["max_tokens"] <= 650
     assert request_payload["max_tokens"] < scan_terminal_service.SCAN_AI_MAX_TOKENS
-    assert '"required_json_keys": ["metar_read_zh", "metar_read_en", "reasoning_zh", "reasoning_en"]' in user_payload
-    assert "Do not return final_judgment" in user_payload
+    assert '"required_json_keys": ["metar_read_zh", "metar_read_en", "predicted_max", "range_low", "range_high", "unit", "confidence", "final_judgment_zh", "final_judgment_en", "reasoning_zh", "reasoning_en"]' in user_payload
+    assert "predicted_max" in user_payload
+    assert "final_judgment" in user_payload
 
 
 def test_city_ai_partial_json_trims_dangling_taf_clause():
diff --git a/web/scan_city_ai_helpers.py b/web/scan_city_ai_helpers.py
index a9018b77..953f3554 100644
--- a/web/scan_city_ai_helpers.py
+++ b/web/scan_city_ai_helpers.py
@@ -25,6 +25,13 @@ CITY_AI_REQUIRED_FIELDS = [
 CITY_AI_STREAM_PROVIDER_FIELDS = [
     "metar_read_zh",
     "metar_read_en",
+    "predicted_max",
+    "range_low",
+    "range_high",
+    "unit",
+    "confidence",
+    "final_judgment_zh",
+    "final_judgment_en",
     "reasoning_zh",
     "reasoning_en",
 ]
@@ -283,6 +290,13 @@ def _city_ai_stream_response_example(unit: str) -> Dict[str, Any]:
     return {
         "metar_read_zh": f"最新 METAR 显示 37.0{unit or '°C'}，报文时间 04:30Z；风和云量暂未显示强降温信号，后续报文用于确认升温路径。",
         "metar_read_en": f"The latest METAR shows 37.0{unit or '°C'} at 04:30Z; wind and cloud signals do not yet show a strong cooling break, so later reports should confirm the warming path.",
+        "predicted_max": 43.0,
+        "range_low": 42.0,
+        "range_high": 44.0,
+        "unit": unit or "°C",
+        "confidence": "medium",
+        "final_judgment_zh": f"预计最高温暂以 43.0{unit or '°C'} 附近为中枢。",
+        "final_judgment_en": f"The expected daily high is centered near 43.0{unit or '°C'}.",
         "reasoning_zh": "当前观测仍贴近上午升温路径，若后续风向转为海风或云雨增强，再下修最高温中枢。",
         "reasoning_en": "The latest observation still fits the morning warming path; revise the daily-high center lower if later wind turns onshore or cloud/rain strengthens.",
     }
diff --git a/web/scan_city_ai_prompt.py b/web/scan_city_ai_prompt.py
index 9a0eb48e..14b5568a 100644
--- a/web/scan_city_ai_prompt.py
+++ b/web/scan_city_ai_prompt.py
@@ -197,18 +197,20 @@ def build_city_ai_stream_request(
     normalized_locale = _normalize_locale(locale)
     context = _observation_prompt_context(ai_input)
     is_airport_metar = context["is_airport_metar"]
-    role_label = "机场 METAR 解读员" if is_airport_metar else "官方观测站解读员"
+    role_label = "机场 METAR 解读与最高温预测员" if is_airport_metar else "官方观测站解读与最高温预测员"
     read_label = context["read_label_zh"]
     source_instruction = context["instruction_zh"]
     system_prompt = (
         f"你是 PolyWeather 的{role_label}。"
         "只返回一个紧凑 JSON object，不要 Markdown。"
-        f"只解读最新观测/报文对今日最高温路径的影响，必须只写 metar_read_zh、metar_read_en、reasoning_zh、reasoning_en 四个字段，便于前端快速显示{read_label}；"
-        "最高温数值、模型一致性和风险清单由后端规则补齐，不要生成这些字段。"
+        f"必须基于最新观测/报文判断该城市今日最高温，输出 metar_read_zh、metar_read_en、predicted_max、range_low、range_high、unit、confidence、final_judgment_zh、final_judgment_en、reasoning_zh、reasoning_en 字段，便于前端快速显示{read_label}和最高温预测；"
+        "模型一致性和风险清单由后端规则补齐，不要生成这些字段。"
         f"{source_instruction}"
-        "观测解读必须具体说明观测/报文时间、温度、风向风速、云量/天气/能见度/露点中与温度路径相关的因素；每个字段最多 1 句。"
+        "观测解读必须具体说明观测/报文时间、温度、风向风速、云量/天气/能见度/露点中与温度路径相关的因素；每个字段最多 1-2 句。"
         "涉及风时要说明当前风向对站点最高温路径倾向增温、降温还是中性，并给出理由。"
         "如果 observation_anchor.is_airport_metar 为 false，不得使用 METAR、TAF、机场报文等称谓。"
+        "predicted_max 是根据最新观测和模型趋势给出的今日最高温数值预测（float），range_low/range_high 是预测区间，unit 为温度单位，confidence 为 low/medium/high。"
+        "final_judgment 用一句话给出今日最高温结论。"
         "所有 *_zh 字段写简体中文，所有 *_en 字段写英文，不得留空。"
         "不要写交易建议、BUY/SELL、Kelly 或套利。"
     )
@@ -226,8 +228,9 @@ def build_city_ai_stream_request(
                     {
                         "locale": normalized_locale,
                         "task": (
-                            "Return JSON keys in this exact order: metar_read_zh, metar_read_en, reasoning_zh, reasoning_en. "
-                            "Do not return final_judgment, predicted_max, ranges, risks or model_cluster_note. Keep it compact. "
+                            "Return JSON keys in this exact order: metar_read_zh, metar_read_en, predicted_max, range_low, range_high, unit, confidence, final_judgment_zh, final_judgment_en, reasoning_zh, reasoning_en. "
+                            "predicted_max must be a float number representing today's predicted daily high temperature based on the latest observation and model trends. "
+                            "Do not return risks or model_cluster_note. Keep it compact. "
                             "Return exactly one JSON object and no markdown."
                         ),
                         "required_json_keys": CITY_AI_STREAM_PROVIDER_FIELDS,