diff --git a/cmd/ingestd/web/app.js b/cmd/ingestd/web/app.js
index 994493b..ecf843c 100644
--- a/cmd/ingestd/web/app.js
+++ b/cmd/ingestd/web/app.js
@@ -23,6 +23,8 @@ const colors = {
   rainStart: "#f77f00",
 };
 
+const RAIN_HOURLY_THRESHOLD_MM = 0.1;
+
 function formatNumber(value, digits) {
   if (value === null || value === undefined) {
     return "--";
@@ -101,7 +103,6 @@ function computeRainIncrements(points) {
     if (prev !== null) {
       delta = p.rain_mm - prev;
       if (delta < 0) delta = 0;
-      if (delta < 0.1) delta = 0;
     }
     prev = p.rain_mm;
     out.push({ x: t, y: delta });
@@ -119,7 +120,7 @@ function computeHourlySums(points, tz) {
   }
   return Array.from(buckets.entries())
     .sort((a, b) => a[0] - b[0])
-    .map(([x, y]) => ({ x, y: y < 0.1 ? 0 : y }));
+    .map(([x, y]) => ({ x, y: y < RAIN_HOURLY_THRESHOLD_MM ? 0 : y }));
 }
 
 function clampRainSeries(points, key) {
@@ -372,6 +373,13 @@ function updateText(id, text) {
   if (el) el.textContent = text;
 }
 
+function observationBucketSummary() {
+  if (state.range === "6h") {
+    return "obs bucket 1m (6h view)";
+  }
+  return "obs bucket 5m (TimescaleDB-aligned)";
+}
+
 function describeBarometer(pressure, trend) {
   if (pressure === null || pressure === undefined) {
     return "No barometer data yet.";
@@ -649,7 +657,7 @@ function renderDashboard(data) {
   const forecastMeta = data.forecast && data.forecast.points && data.forecast.points.length
     ? `forecast retrieved ${formatDateTime(data.forecast.retrieved_at)}`
     : "forecast not available";
-  updateText("forecast-meta", forecastMeta);
+  updateText("forecast-meta", `${forecastMeta} | ${observationBucketSummary()}`);
 
   if (latest) {
     updateText("live-temp", `${formatNumber(latest.temp_c, 2)} C`);
@@ -852,7 +860,7 @@ function renderDashboard(data) {
   updateText("live-rain-hour", latestRainHour == null ? "--" : `${formatNumber(latestRainHour, 2)} mm`);
   const rainTitle = document.getElementById("chart-rain-title");
   if (rainTitle) {
-    rainTitle.textContent = "Rain (obs hourly sum vs forecast)";
+    rainTitle.textContent = `Rain (obs hourly sum from ${state.bucket} buckets vs forecast)`;
   }
 
   const forecastRain = clampRainSeries(forecastLine, "precip_mm");
@@ -861,7 +869,7 @@ function renderDashboard(data) {
       datasets: [
         {
           type: "line",
-          label: "obs hourly sum (mm)",
+          label: `obs hourly sum (mm, ${state.bucket} buckets)`,
           data: rainHourly,
           borderColor: colors.rain,
           yAxisID: "y",
diff --git a/internal/db/series.go b/internal/db/series.go
index f9ebb7f..6b3959e 100644
--- a/internal/db/series.go
+++ b/internal/db/series.go
@@ -74,7 +74,7 @@ func (d *DB) ObservationSeries(ctx context.Context, site, bucket string, start,
 				max(light_lux) AS light_lux_max,
 				avg(battery_mv) AS battery_mv_avg,
 				avg(supercap_v) AS supercap_v_avg,
-				avg(rain_mm) AS rain_mm_avg,
+				max(rain_mm) AS rain_mm_avg,
 				max(rain_start) AS rain_start_max
 			FROM observations_ws90
 			WHERE site = $1