diff --git a/agents/weather_briefing.py b/agents/weather_briefing.py
index 94abd35..63c8879 100644
--- a/agents/weather_briefing.py
+++ b/agents/weather_briefing.py
@@ -121,26 +121,76 @@ def format_briefing(weather):
     return md, f"{condition}, {temp}°F (feels like {feels}°F), wind {wind} mph"
 
 
-def post_to_wiki(markdown, date_str):
-    """Create or update a daily briefing doc in Outline."""
-    headers = {
-        "Authorization": f"Bearer {WIKI_TOKEN}",
-    }
+MONTH_NAMES = [
+    "", "January", "February", "March", "April", "May", "June",
+    "July", "August", "September", "October", "November", "December",
+]
 
-    # Search for existing doc with today's date
-    title = f"Daily Briefing — {date_str}"
-    search_result = api_request(
+
+def find_child_doc(parent_id, title, headers):
+    """Search for a child doc by title under a given parent."""
+    result = api_request(
         f"{WIKI_API}/documents.search",
         data={"query": title, "collectionId": WIKI_COLLECTION_ID},
         headers=headers,
         method="POST",
     )
+    for doc in result.get("data", []):
+        d = doc.get("document", {})
+        if d.get("title") == title and d.get("parentDocumentId") == parent_id:
+            return d["id"]
+    return None
 
-    doc_id = None
-    for doc in search_result.get("data", []):
-        if doc.get("document", {}).get("title") == title:
-            doc_id = doc["document"]["id"]
-            break
+
+def ensure_child_doc(parent_id, title, body, headers):
+    """Find or create a child doc under a parent. Returns doc ID."""
+    doc_id = find_child_doc(parent_id, title, headers)
+    if doc_id:
+        return doc_id
+    result = api_request(
+        f"{WIKI_API}/documents.create",
+        data={
+            "title": title,
+            "text": body,
+            "collectionId": WIKI_COLLECTION_ID,
+            "parentDocumentId": parent_id,
+            "publish": True,
+        },
+        headers=headers,
+        method="POST",
+    )
+    print(f"Created wiki doc: {title}")
+    return result["data"]["id"]
+
+
+def post_to_wiki(markdown, date_str):
+    """Create or update a daily briefing doc in Outline.
+
+    Hierarchy: Eric's Daily Briefing → {Year} → {Month} → Daily Briefing — {date}
+    """
+    headers = {
+        "Authorization": f"Bearer {WIKI_TOKEN}",
+    }
+
+    now = datetime.now(MT)
+    year_str = str(now.year)
+    month_str = MONTH_NAMES[now.month]
+
+    # Ensure year doc exists under Eric's Daily Briefing
+    year_id = ensure_child_doc(
+        WIKI_PARENT_DOC_ID, year_str,
+        f"Daily briefings for {year_str}.", headers,
+    )
+
+    # Ensure month doc exists under year
+    month_id = ensure_child_doc(
+        year_id, month_str,
+        f"Daily briefings for {month_str} {year_str}.", headers,
+    )
+
+    # Search for existing doc with today's date under the month
+    title = f"Daily Briefing — {date_str}"
+    doc_id = find_child_doc(month_id, title, headers)
 
     if doc_id:
         api_request(
@@ -157,7 +207,7 @@ def post_to_wiki(markdown, date_str):
                 "title": title,
                 "text": markdown,
                 "collectionId": WIKI_COLLECTION_ID,
-                "parentDocumentId": WIKI_PARENT_DOC_ID,
+                "parentDocumentId": month_id,
                 "publish": True,
             },
             headers=headers,