Month pages: show record high and low for every metric (#113)

The per-month records section listed only the warmest and coldest temperature.
Extend it to a card per metric (High, Low, Feels-like, Humidity, Wind, Gust,
Precip), each showing that calendar month's record high and low with the date.

Precip is special-cased: a per-day record low is just zero, and the dry-streak
helper would bridge year boundaries on month-filtered rows, so the wettest and
driest sides use the month's largest and smallest total accumulation, dated to
the year. Partial current months (< 26 days) are excluded so an unfinished month
can't win "driest" on a fraction of its rainfall.

Reuses the records page's card grid, so it's already vertical on mobile.

Claude-Session: https://claude.ai/code/session_01XXxmNFy9cZ6Gh8Y9thZn62

content.py

@@ -408,13 +408,39 @@ def _month_context(request, city, history, month_idx: int) -> dict:
         stats.append(("Typical low range", f"{_temp(tmin['p10'])} to {_temp(tmin['p90'])}"))
     if precip:
         stats.append(("Average daily precipitation", f"{precip['mean']:.2f} in"))
+    # Record high and low for every metric in this calendar month (mirrors the
+    # all-time records cards, but scoped to the month). Precip is special-cased:
+    # a per-day "record low" is just zero, and the dry-streak helper would wrongly
+    # bridge year boundaries on month-filtered rows, so the wettest/driest sides
+    # show this month's largest and smallest total accumulation, dated to the year.
     records = []
-    if mrec.get("tmax"):
-        records.append({"label": "Warmest on record", "value": _temp(mrec["tmax"]["max"]),
-                        "date": mrec["tmax"]["max_date"], "cls": temp_class(mrec["tmax"]["max"])})
-    if mrec.get("tmin"):
-        records.append({"label": "Coldest on record", "value": _temp(mrec["tmin"]["min"]),
-                        "date": mrec["tmin"]["min_date"], "cls": temp_class(mrec["tmin"]["min"])})
+    for key, label in METRIC_LABELS:
+        r = mrec.get(key)
+        if not r:
+            continue
+        if key == "precip":
+            # Only whole months count — a partial current month would otherwise win
+            # "driest" on a fraction of its rainfall.
+            totals = (mdf.filter(pl.col("precip").is_not_null())
+                         .group_by(pl.col("date").dt.year().alias("yr"))
+                         .agg(pl.col("precip").sum().alias("total"),
+                              pl.len().alias("days"))
+                         .filter(pl.col("days") >= 26)
+                         .sort("total"))
+            if totals.is_empty():
+                continue
+            lo, hi = totals.row(0, named=True), totals.row(totals.height - 1, named=True)
+            records.append({
+                "label": label,
+                "high": f"{hi['total']:.1f} in", "high_date": str(hi["yr"]), "high_tag": "Wettest",
+                "low": f"{lo['total']:.1f} in", "low_date": str(lo["yr"]), "low_tag": "Driest",
+            })
+        else:
+            records.append({
+                "label": label,
+                "high": _fmt(key, r["max"]), "high_date": r["max_date"], "high_tag": "Highest",
+                "low": _fmt(key, r["min"]), "low_date": r["min_date"], "low_tag": "Lowest",
+            })
 
     prev_i = 12 if month_idx == 1 else month_idx - 1
     next_i = 1 if month_idx == 12 else month_idx + 1

templates/month.html.j2

@@ -24,10 +24,26 @@
 
   {% if records %}
   <h2>{{ month_name }} records</h2>
-  <ul class="climate-records">
-    {% for r in records %}<li><b>{{ r.label }}:</b>
-      <span class="t-inline t-{{ r.cls }}">{{ r.value }}</span> on {{ r.date }}</li>{% endfor %}
-  </ul>
+  <p class="muted">The most extreme {{ month_name }} on record for each metric, across
+     {{ year_range[0] }}–{{ year_range[1] }}. For rainfall, the wettest and driest are by
+     total {{ month_name }} accumulation.</p>
+  <div class="records-grid">
+    {% for r in records %}
+    <div class="record-card">
+      <h3 class="rc-metric">{{ r.label }}</h3>
+      <div class="rc-row rc-high">
+        <span class="rc-tag">{{ r.high_tag }}</span>
+        <span class="rc-val">{{ r.high }}</span>
+        <span class="rc-date">{{ r.high_date }}</span>
+      </div>
+      <div class="rc-row rc-low">
+        <span class="rc-tag">{{ r.low_tag }}</span>
+        <span class="rc-val">{{ r.low }}</span>
+        <span class="rc-date">{{ r.low_date }}</span>
+      </div>
+    </div>
+    {% endfor %}
+  </div>
   {% endif %}
 
   <p><a class="cta" href="{{ base }}/#{{ tool_hash }}">See {{ name }}'s live weather grade →</a></p>

tests/test_content.py

@@ -100,6 +100,22 @@ def test_month_and_records(client):
     assert client.get(f"{B}/climate/{SLUG}/notamonth").status_code == 404
 
 
+def test_month_records_cover_every_metric_high_and_low(client):
+    # The month page's records show a record high AND low for each metric present, not
+    # just warmest/coldest temperature — one card per metric with both extremes. (The
+    # test fixture carries tmax/tmin/precip; real cities add feels/humidity/wind/gust.)
+    b = client.get(f"{B}/climate/{SLUG}/july").text
+    assert "July records" in b
+    for label in ("High", "Low", "Precip"):
+        assert f'class="rc-metric">{label}<' in b
+    # Every card carries a labelled high and low row (temp metrics use Highest/Lowest).
+    n = b.count('rc-row rc-high')
+    assert n >= 3 and b.count('rc-row rc-low') == n
+    assert "Highest" in b and "Lowest" in b
+    # Precip's extremes are the wettest/driest whole month by total accumulation.
+    assert "Wettest" in b and "Driest" in b
+
+
 def test_records_page_has_monthly_and_seasonal(client):
     b = client.get(f"{B}/climate/{SLUG}/records").text
     # Monthly records: all 12 months, each linking to its month page.