diff --git a/docs/internal/generatedtext.md b/docs/internal/generatedtext.md
new file mode 100644
index 0000000..49637fb
--- /dev/null
+++ b/docs/internal/generatedtext.md
@@ -0,0 +1,73 @@
+# Generated Text Internals
+
+This document describes structured generated-text handling in
+`internal/generatedtext`.
+
+## Purpose
+
+`internal/generatedtext` validates structured text returned for
+generated-text-template reports and builds curated render contexts for
+templates. The first implemented contract is the Hourly Report.
+
+## Inputs And Outputs
+
+Inputs:
+
+- raw Hourly Report GeneratedText JSON
+- report metadata from `internal/briefing`
+- a module snapshot from `internal/module`
+- validated hourly generated text
+
+Outputs:
+
+- typed `Hourly` generated text
+- normalized stable JSON for validated hourly generated text
+- typed `HourlyRenderContext` values for `internal/reporttemplate`
+
+The hourly generated text JSON accepts:
+
+```json
+{
+  "summary": "string",
+  "timing": "string",
+  "impacts": "string",
+  "confidence": "string"
+}
+```
+
+`summary`, `timing`, and `impacts` are required after trimming whitespace.
+`confidence` is optional and omitted from normalized JSON when blank.
+
+## Boundaries
+
+- This package owns typed generated-text validation and render-context shaping.
+- It uses typed module snapshot decoding through `module.StanzaValue`.
+- It does not invoke Scriptorium, write state artifacts, choose report
+  definitions, compare snapshots, or render templates directly in production
+  workflows.
+- It does not use a Go JSON Schema dependency; schema enforcement in Go is
+  limited to typed JSON decoding, unknown-field rejection, and required-field
+  checks.
+
+## Failure Behavior
+
+- Malformed generated-text JSON fails with decode context.
+- Unknown generated-text JSON fields fail during decoding.
+- Empty required hourly fields fail after trimming whitespace.
+- Missing required render-context stanzas fail with the stanza name.
+- Invalid render metadata, including missing timezone, missing generated time,
+  or invalid valid period, fails before template rendering.
+
+## Tests
+
+Inspect:
+
+- `internal/generatedtext/hourly_test.go`
+- `internal/generatedtext/render_context_test.go`
+
+## Invariants
+
+- Render contexts are curated structs, not raw prompt-input packages.
+- Required generated text is normalized before downstream artifact storage.
+- Missing optional weather narrative stanzas produce empty or fallback render
+  context fields rather than forcing raw module data into templates.
diff --git a/internal/generatedtext/hourly.go b/internal/generatedtext/hourly.go
new file mode 100644
index 0000000..f7aa8a3
--- /dev/null
+++ b/internal/generatedtext/hourly.go
@@ -0,0 +1,55 @@
+// Package generatedtext validates structured LLM text and render contexts.
+package generatedtext
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"strings"
+)
+
+type Hourly struct {
+	Summary    string `json:"summary"`
+	Timing     string `json:"timing"`
+	Impacts    string `json:"impacts"`
+	Confidence string `json:"confidence,omitempty"`
+}
+
+func ValidateHourly(data []byte) (Hourly, []byte, error) {
+	decoder := json.NewDecoder(bytes.NewReader(data))
+	decoder.DisallowUnknownFields()
+
+	var value Hourly
+	if err := decoder.Decode(&value); err != nil {
+		return Hourly{}, nil, fmt.Errorf("decode hourly generated text: %w", err)
+	}
+	var extra any
+	if err := decoder.Decode(&extra); err != nil {
+		if err != io.EOF {
+			return Hourly{}, nil, fmt.Errorf("decode hourly generated text: %w", err)
+		}
+	} else {
+		return Hourly{}, nil, fmt.Errorf("decode hourly generated text: multiple JSON values")
+	}
+
+	value.Summary = strings.TrimSpace(value.Summary)
+	value.Timing = strings.TrimSpace(value.Timing)
+	value.Impacts = strings.TrimSpace(value.Impacts)
+	value.Confidence = strings.TrimSpace(value.Confidence)
+	if value.Summary == "" {
+		return Hourly{}, nil, fmt.Errorf("hourly generated text summary is required")
+	}
+	if value.Timing == "" {
+		return Hourly{}, nil, fmt.Errorf("hourly generated text timing is required")
+	}
+	if value.Impacts == "" {
+		return Hourly{}, nil, fmt.Errorf("hourly generated text impacts is required")
+	}
+
+	normalized, err := json.Marshal(value)
+	if err != nil {
+		return Hourly{}, nil, fmt.Errorf("normalize hourly generated text: %w", err)
+	}
+	return value, normalized, nil
+}
diff --git a/internal/generatedtext/hourly_test.go b/internal/generatedtext/hourly_test.go
new file mode 100644
index 0000000..2aae71b
--- /dev/null
+++ b/internal/generatedtext/hourly_test.go
@@ -0,0 +1,86 @@
+package generatedtext
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestValidateHourlyNormalizesJSON(t *testing.T) {
+	value, normalized, err := ValidateHourly([]byte(`{
+		"timing": "  main window late morning ",
+		"summary": " Storm chances increase. ",
+		"confidence": " Medium ",
+		"impacts": " Brief downpours. "
+	}`))
+	if err != nil {
+		t.Fatalf("ValidateHourly() error = %v", err)
+	}
+	if value.Summary != "Storm chances increase." {
+		t.Fatalf("Summary = %q, want trimmed summary", value.Summary)
+	}
+	want := `{"summary":"Storm chances increase.","timing":"main window late morning","impacts":"Brief downpours.","confidence":"Medium"}`
+	if string(normalized) != want {
+		t.Fatalf("normalized = %s, want %s", normalized, want)
+	}
+}
+
+func TestValidateHourlyOmitsEmptyConfidence(t *testing.T) {
+	_, normalized, err := ValidateHourly([]byte(`{
+		"summary": "Storm chances increase.",
+		"timing": "Late morning.",
+		"impacts": "Brief downpours.",
+		"confidence": "   "
+	}`))
+	if err != nil {
+		t.Fatalf("ValidateHourly() error = %v", err)
+	}
+	want := `{"summary":"Storm chances increase.","timing":"Late morning.","impacts":"Brief downpours."}`
+	if string(normalized) != want {
+		t.Fatalf("normalized = %s, want %s", normalized, want)
+	}
+}
+
+func TestValidateHourlyRejectsInvalidInput(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{
+			name: "malformed",
+			in:   `{`,
+			want: "decode hourly generated text",
+		},
+		{
+			name: "unknown field",
+			in:   `{"summary":"Storm chances increase.","timing":"Late morning.","impacts":"Brief downpours.","extra":"value"}`,
+			want: `unknown field "extra"`,
+		},
+		{
+			name: "missing summary",
+			in:   `{"timing":"Late morning.","impacts":"Brief downpours."}`,
+			want: "summary is required",
+		},
+		{
+			name: "blank timing",
+			in:   `{"summary":"Storm chances increase.","timing":"  ","impacts":"Brief downpours."}`,
+			want: "timing is required",
+		},
+		{
+			name: "multiple values",
+			in:   `{"summary":"Storm chances increase.","timing":"Late morning.","impacts":"Brief downpours."} {}`,
+			want: "multiple JSON values",
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			_, _, err := ValidateHourly([]byte(test.in))
+			if err == nil {
+				t.Fatal("ValidateHourly() error = nil, want error")
+			}
+			if !strings.Contains(err.Error(), test.want) {
+				t.Fatalf("ValidateHourly() error = %v, want %q", err, test.want)
+			}
+		})
+	}
+}
diff --git a/internal/generatedtext/render_context.go b/internal/generatedtext/render_context.go
new file mode 100644
index 0000000..6685135
--- /dev/null
+++ b/internal/generatedtext/render_context.go
@@ -0,0 +1,360 @@
+package generatedtext
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
+)
+
+type HourlyRenderContext struct {
+	ReportTitle         string
+	LocationName        string
+	ValidPeriod         string
+	GeneratedAt         string
+	GeneratedText       Hourly
+	CurrentConditions   string
+	HourlyForecast      []HourlyForecastRow
+	PrecipitationTiming string
+	Alerts              []string
+	SPCOutlooks         []string
+	ForecastDiscussion  ForecastDiscussion
+	SPCDiscussions      []string
+	WeatherStory        string
+}
+
+type HourlyForecastRow struct {
+	Time          string
+	Summary       string
+	Temperature   string
+	Precipitation string
+	Wind          string
+}
+
+type ForecastDiscussion struct {
+	KeyMessages []string
+	ShortTerm   string
+}
+
+func BuildHourlyRenderContext(metadata briefing.Metadata, snapshot module.Snapshot, generated Hourly) (HourlyRenderContext, error) {
+	location, err := timeutil.LoadLocation(metadata.Timezone)
+	if err != nil {
+		return HourlyRenderContext{}, fmt.Errorf("build hourly render context: %w", err)
+	}
+	if metadata.GeneratedAt.IsZero() {
+		return HourlyRenderContext{}, fmt.Errorf("build hourly render context: generatedAt is required")
+	}
+	if !metadata.ValidPeriod.IsValid() {
+		return HourlyRenderContext{}, fmt.Errorf("build hourly render context: valid period is required")
+	}
+
+	current, err := requiredStanza[briefing.CurrentConditionsModule](snapshot, string(module.CurrentConditions))
+	if err != nil {
+		return HourlyRenderContext{}, err
+	}
+	hourly, err := requiredStanza[briefing.HourlyForecastModule](snapshot, string(module.HourlyForecast))
+	if err != nil {
+		return HourlyRenderContext{}, err
+	}
+	precip, err := requiredStanza[briefing.PrecipTimingModule](snapshot, string(module.PrecipTiming))
+	if err != nil {
+		return HourlyRenderContext{}, err
+	}
+	alerts, err := requiredStanza[briefing.AlertDigestModule](snapshot, string(module.AlertDigest))
+	if err != nil {
+		return HourlyRenderContext{}, err
+	}
+	outlooks, err := requiredStanza[briefing.SPCConvectiveOutlooksModule](snapshot, string(module.SPCConvectiveOutlooks))
+	if err != nil {
+		return HourlyRenderContext{}, err
+	}
+	discussion, err := optionalStanza[briefing.AreaForecastDiscussionModule](snapshot, string(module.AreaForecastDiscussion))
+	if err != nil {
+		return HourlyRenderContext{}, err
+	}
+	spcDiscussion, err := optionalStanza[briefing.SPCConvectiveDiscussionModule](snapshot, string(module.SPCConvectiveDiscussion))
+	if err != nil {
+		return HourlyRenderContext{}, err
+	}
+	story, err := optionalStanza[briefing.WeatherStoryModule](snapshot, string(module.WeatherStory))
+	if err != nil {
+		return HourlyRenderContext{}, err
+	}
+
+	return HourlyRenderContext{
+		ReportTitle:         "Hourly Report",
+		LocationName:        locationName(metadata),
+		ValidPeriod:         periodLabel(metadata.ValidPeriod, location),
+		GeneratedAt:         timeLabel(metadata.GeneratedAt, location),
+		GeneratedText:       generated,
+		CurrentConditions:   currentConditionsLabel(current),
+		HourlyForecast:      hourlyForecastRows(hourly),
+		PrecipitationTiming: precipitationTimingLabel(precip),
+		Alerts:              alertLabels(alerts),
+		SPCOutlooks:         outlookLabels(outlooks),
+		ForecastDiscussion: ForecastDiscussion{
+			KeyMessages: append([]string(nil), discussion.KeyMessages...),
+			ShortTerm:   discussion.ShortTerm,
+		},
+		SPCDiscussions: spcDiscussionLabels(spcDiscussion),
+		WeatherStory:   weatherStoryLabel(story),
+	}, nil
+}
+
+func requiredStanza[T any](snapshot module.Snapshot, name string) (T, error) {
+	value, ok, err := module.StanzaValue[T](snapshot, name)
+	if err != nil {
+		var zero T
+		return zero, fmt.Errorf("build hourly render context: %w", err)
+	}
+	if !ok {
+		var zero T
+		return zero, fmt.Errorf("build hourly render context requires stanza %q", name)
+	}
+	return value, nil
+}
+
+func optionalStanza[T any](snapshot module.Snapshot, name string) (T, error) {
+	value, _, err := module.StanzaValue[T](snapshot, name)
+	if err != nil {
+		var zero T
+		return zero, fmt.Errorf("build hourly render context: %w", err)
+	}
+	return value, nil
+}
+
+func locationName(metadata briefing.Metadata) string {
+	if metadata.Location != nil {
+		if metadata.Location.Name != "" && metadata.Location.Region != "" {
+			return metadata.Location.Name + ", " + metadata.Location.Region
+		}
+		if metadata.Location.Name != "" {
+			return metadata.Location.Name
+		}
+	}
+	if metadata.SourceLocation != "" {
+		return metadata.SourceLocation
+	}
+	if metadata.SourceLocationID != "" {
+		return metadata.SourceLocationID
+	}
+	return "Unknown location"
+}
+
+func periodLabel(period timeutil.Period, location *time.Location) string {
+	return fmt.Sprintf("%s to %s", timeLabel(period.Start, location), timeLabel(period.End, location))
+}
+
+func timeLabel(value time.Time, location *time.Location) string {
+	return value.In(location).Format("2006-01-02 at 3:04 PM")
+}
+
+func currentConditionsLabel(current briefing.CurrentConditionsModule) string {
+	parts := []string{}
+	if current.ConditionText != "" {
+		parts = append(parts, current.ConditionText)
+	}
+	if temperature := temperatureLabel(current.TemperatureF, current.TemperatureC); temperature != "" {
+		parts = append(parts, temperature)
+	}
+	if apparent := temperatureLabel(current.ApparentTemperatureF, current.ApparentTemperatureC); apparent != "" {
+		parts = append(parts, "feels like "+apparent)
+	}
+	if current.RelativeHumidityPercent != nil {
+		parts = append(parts, fmt.Sprintf("humidity %d%%", rounded(*current.RelativeHumidityPercent)))
+	}
+	if wind := windLabel(current.WindDirection, current.WindSpeedMph, current.WindSpeedKmh, nil, nil); wind != "" {
+		parts = append(parts, wind)
+	}
+	if len(parts) == 0 {
+		return "No current conditions available."
+	}
+	return strings.Join(parts, "; ") + "."
+}
+
+func hourlyForecastRows(hourly briefing.HourlyForecastModule) []HourlyForecastRow {
+	rows := make([]HourlyForecastRow, 0, len(hourly.Periods))
+	for _, period := range hourly.Periods {
+		summary := period.TextDescription
+		if summary == "" {
+			summary = period.Name
+		}
+		rows = append(rows, HourlyForecastRow{
+			Time:          firstNonEmpty(period.PeriodBegins, period.Name),
+			Summary:       summary,
+			Temperature:   temperatureLabel(period.TemperatureF, period.TemperatureC),
+			Precipitation: precipitationLabel(period.ProbabilityOfPrecipitationPercent),
+			Wind:          windLabel(period.WindDirection, period.WindSpeedMph, period.WindSpeedKmh, period.WindGustMph, period.WindGustKmh),
+		})
+	}
+	return rows
+}
+
+func precipitationTimingLabel(timing briefing.PrecipTimingModule) string {
+	parts := []string{}
+	if timing.MaxPopPercent != nil {
+		max := fmt.Sprintf("Peak precipitation probability %d%%", *timing.MaxPopPercent)
+		if timing.MaxPopTime != "" {
+			max += " at " + timing.MaxPopTime
+		}
+		parts = append(parts, max)
+	}
+	for _, window := range timing.PrecipitationWindows {
+		label := window.PeriodBegins
+		if window.PeriodEnds != "" {
+			label += " to " + window.PeriodEnds
+		}
+		if window.MaxPopPercent != nil {
+			label += fmt.Sprintf(" (max %d%%", *window.MaxPopPercent)
+			if window.MaxPopTime != "" {
+				label += " at " + window.MaxPopTime
+			}
+			label += ")"
+		}
+		parts = append(parts, label)
+	}
+	if timing.ThunderMentioned {
+		parts = append(parts, "Thunder is mentioned in the forecast.")
+	}
+	if len(parts) == 0 {
+		return "No precipitation timing signal above threshold."
+	}
+	return strings.Join(parts, "; ")
+}
+
+func alertLabels(alerts briefing.AlertDigestModule) []string {
+	if alerts.Missing {
+		return []string{"Alert source missing."}
+	}
+	out := make([]string, 0, len(alerts.Relevant))
+	for _, alert := range alerts.Relevant {
+		main := firstNonEmpty(alert.Event, alert.Headline)
+		if main == "" {
+			continue
+		}
+		if alert.Headline != "" && alert.Headline != main {
+			main += ": " + alert.Headline
+		}
+		if alert.Severity != "" {
+			main += " (" + alert.Severity + ")"
+		}
+		out = append(out, main)
+	}
+	return out
+}
+
+func outlookLabels(outlooks briefing.SPCConvectiveOutlooksModule) []string {
+	out := make([]string, 0, len(outlooks.Outlooks))
+	for _, outlook := range outlooks.Outlooks {
+		label := firstNonEmpty(outlook.LabelText, outlook.Label, outlook.OutlookType)
+		if label == "" {
+			continue
+		}
+		if outlook.PeriodBegins != "" {
+			label += " from " + outlook.PeriodBegins
+			if outlook.PeriodEnds != "" {
+				label += " to " + outlook.PeriodEnds
+			}
+		}
+		out = append(out, label)
+	}
+	return out
+}
+
+func spcDiscussionLabels(discussion briefing.SPCConvectiveDiscussionModule) []string {
+	out := make([]string, 0, len(discussion.Discussions))
+	for _, record := range discussion.Discussions {
+		label := firstNonEmpty(record.Headline, record.Summary, record.Discussion)
+		if label == "" {
+			continue
+		}
+		if record.Summary != "" && record.Summary != label {
+			label += ": " + record.Summary
+		}
+		out = append(out, label)
+	}
+	return out
+}
+
+func weatherStoryLabel(story briefing.WeatherStoryModule) string {
+	if !story.Available {
+		return "No weather story available."
+	}
+	parts := []string{}
+	if story.Title != "" {
+		parts = append(parts, story.Title)
+	}
+	if story.Description != "" {
+		parts = append(parts, story.Description)
+	}
+	if len(parts) == 0 {
+		return "Weather story is available."
+	}
+	return strings.Join(parts, " - ")
+}
+
+func temperatureLabel(fahrenheit *float64, celsius *float64) string {
+	if fahrenheit != nil {
+		return fmt.Sprintf("%d F", rounded(*fahrenheit))
+	}
+	if celsius != nil {
+		return fmt.Sprintf("%d C", rounded(*celsius))
+	}
+	return ""
+}
+
+func precipitationLabel(percent *float64) string {
+	if percent == nil {
+		return ""
+	}
+	return fmt.Sprintf("%d%% precipitation", rounded(*percent))
+}
+
+func windLabel(direction string, mph *float64, kmh *float64, gustMph *float64, gustKmh *float64) string {
+	speed := ""
+	if mph != nil {
+		speed = fmt.Sprintf("%d mph", rounded(*mph))
+	} else if kmh != nil {
+		speed = fmt.Sprintf("%d km/h", rounded(*kmh))
+	}
+	if direction != "" && speed != "" {
+		speed = direction + " " + speed
+	} else if direction != "" {
+		speed = direction + " wind"
+	}
+	gust := ""
+	if gustMph != nil {
+		gust = fmt.Sprintf("gusts %d mph", rounded(*gustMph))
+	} else if gustKmh != nil {
+		gust = fmt.Sprintf("gusts %d km/h", rounded(*gustKmh))
+	}
+	switch {
+	case speed != "" && gust != "":
+		return "wind " + speed + ", " + gust
+	case speed != "":
+		return "wind " + speed
+	case gust != "":
+		return "wind " + gust
+	default:
+		return ""
+	}
+}
+
+func rounded(value float64) int {
+	if value < 0 {
+		return int(value - 0.5)
+	}
+	return int(value + 0.5)
+}
+
+func firstNonEmpty(values ...string) string {
+	for _, value := range values {
+		if value != "" {
+			return value
+		}
+	}
+	return ""
+}
diff --git a/internal/generatedtext/render_context_test.go b/internal/generatedtext/render_context_test.go
new file mode 100644
index 0000000..67e1cab
--- /dev/null
+++ b/internal/generatedtext/render_context_test.go
@@ -0,0 +1,249 @@
+package generatedtext
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/reporttemplate"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
+)
+
+func TestBuildHourlyRenderContext(t *testing.T) {
+	metadata := testMetadata()
+	snapshot := testSnapshot(t)
+	generated := Hourly{
+		Summary:    "Storm chances increase through late morning.",
+		Timing:     "The main window is 10 AM to noon.",
+		Impacts:    "Brief downpours may slow travel.",
+		Confidence: "Medium confidence in timing.",
+	}
+	ctx, err := BuildHourlyRenderContext(metadata, snapshot, generated)
+	if err != nil {
+		t.Fatalf("BuildHourlyRenderContext() error = %v", err)
+	}
+	if ctx.ReportTitle != "Hourly Report" {
+		t.Fatalf("ReportTitle = %q, want Hourly Report", ctx.ReportTitle)
+	}
+	if ctx.LocationName != "Brentwood, MO" {
+		t.Fatalf("LocationName = %q, want Brentwood, MO", ctx.LocationName)
+	}
+	if ctx.ValidPeriod != "2026-05-29 at 8:30 AM to 2026-05-29 at 2:30 PM" {
+		t.Fatalf("ValidPeriod = %q, want friendly period", ctx.ValidPeriod)
+	}
+	if ctx.CurrentConditions != "Partly cloudy; 74 F; feels like 76 F; humidity 71%; wind S 8 mph." {
+		t.Fatalf("CurrentConditions = %q, want deterministic summary", ctx.CurrentConditions)
+	}
+	if len(ctx.HourlyForecast) != 2 {
+		t.Fatalf("HourlyForecast length = %d, want 2", len(ctx.HourlyForecast))
+	}
+	if row := ctx.HourlyForecast[1]; row.Time != "2026-05-29 at 10:00 AM" || row.Summary != "Showers" || row.Precipitation != "70% precipitation" {
+		t.Fatalf("HourlyForecast[1] = %#v, want 10 AM showers row", row)
+	}
+	if !strings.Contains(ctx.PrecipitationTiming, "Peak precipitation probability 70% at 10 AM") {
+		t.Fatalf("PrecipitationTiming = %q, want peak probability", ctx.PrecipitationTiming)
+	}
+	if strings.Join(ctx.Alerts, "|") != "Flood Watch: Flood Watch until early afternoon (Moderate)" {
+		t.Fatalf("Alerts = %#v, want alert label", ctx.Alerts)
+	}
+	if strings.Join(ctx.SPCOutlooks, "|") != "Slight Risk from 2026-05-29 at 7:00 AM to 2026-05-29 at 3:00 PM" {
+		t.Fatalf("SPCOutlooks = %#v, want outlook label", ctx.SPCOutlooks)
+	}
+	if ctx.ForecastDiscussion.ShortTerm != "Short-term discussion favors increasing rain coverage." {
+		t.Fatalf("ForecastDiscussion.ShortTerm = %q, want discussion text", ctx.ForecastDiscussion.ShortTerm)
+	}
+	if strings.Join(ctx.SPCDiscussions, "|") != "Mesoscale discussion: Strong storms may develop late morning." {
+		t.Fatalf("SPCDiscussions = %#v, want discussion label", ctx.SPCDiscussions)
+	}
+	if ctx.WeatherStory != "Morning storms - Morning storms remain the main story." {
+		t.Fatalf("WeatherStory = %q, want story label", ctx.WeatherStory)
+	}
+
+	rendered, err := reporttemplate.Render("hourly", ctx)
+	if err != nil {
+		t.Fatalf("Render() error = %v", err)
+	}
+	text := string(rendered)
+	for _, want := range []string{
+		"# Hourly Report",
+		"Storm chances increase through late morning.",
+		"- 2026-05-29 at 10:00 AM: Showers; 75 F; 70% precipitation; wind S 10 mph, gusts 18 mph",
+		"- Flood Watch: Flood Watch until early afternoon (Moderate)",
+		"Morning storms - Morning storms remain the main story.",
+	} {
+		if !strings.Contains(text, want) {
+			t.Fatalf("rendered template missing %q:\n%s", want, text)
+		}
+	}
+}
+
+func TestBuildHourlyRenderContextRequiresCoreStanzas(t *testing.T) {
+	snapshot, err := module.NewSnapshot([]module.Output{
+		{ID: module.CurrentConditions, StanzaName: string(module.CurrentConditions), Value: briefing.CurrentConditionsModule{}},
+	})
+	if err != nil {
+		t.Fatalf("NewSnapshot() error = %v", err)
+	}
+	_, err = BuildHourlyRenderContext(testMetadata(), snapshot, Hourly{
+		Summary: "Storm chances increase.",
+		Timing:  "Late morning.",
+		Impacts: "Brief downpours.",
+	})
+	if err == nil {
+		t.Fatal("BuildHourlyRenderContext() error = nil, want missing stanza error")
+	}
+	if !strings.Contains(err.Error(), `requires stanza "hourly_forecast"`) {
+		t.Fatalf("BuildHourlyRenderContext() error = %v, want missing hourly forecast stanza", err)
+	}
+}
+
+func testMetadata() briefing.Metadata {
+	generatedAt := time.Date(2026, 5, 29, 13, 30, 0, 0, time.UTC)
+	return briefing.Metadata{
+		RunID:       "run-1",
+		ReportID:    report.Hourly,
+		PromptID:    "weather.hourly_generated_text",
+		GeneratedAt: generatedAt,
+		Units:       "imperial",
+		Timezone:    "America/Chicago",
+		ValidPeriod: timeutil.Period{
+			Start: generatedAt,
+			End:   generatedAt.Add(6 * time.Hour),
+		},
+		Location: &briefing.LocationContext{
+			Name:   "Brentwood",
+			Region: "MO",
+		},
+	}
+}
+
+func testSnapshot(t *testing.T) module.Snapshot {
+	t.Helper()
+	snapshot, err := module.NewSnapshot([]module.Output{
+		{
+			ID:         module.CurrentConditions,
+			StanzaName: string(module.CurrentConditions),
+			Value: briefing.CurrentConditionsModule{
+				ConditionText:           "Partly cloudy",
+				TemperatureF:            floatPtr(74),
+				ApparentTemperatureF:    floatPtr(76),
+				RelativeHumidityPercent: floatPtr(71),
+				WindSpeedMph:            floatPtr(8),
+				WindDirection:           "S",
+			},
+		},
+		{
+			ID:         module.HourlyForecast,
+			StanzaName: string(module.HourlyForecast),
+			Value: briefing.HourlyForecastModule{
+				Periods: []briefing.HourlyForecastPeriod{
+					{
+						PeriodBegins:                      "2026-05-29 at 9:00 AM",
+						TextDescription:                   "Cloudy",
+						TemperatureF:                      floatPtr(74),
+						ProbabilityOfPrecipitationPercent: floatPtr(30),
+						WindSpeedMph:                      floatPtr(8),
+						WindDirection:                     "S",
+					},
+					{
+						PeriodBegins:                      "2026-05-29 at 10:00 AM",
+						TextDescription:                   "Showers",
+						TemperatureF:                      floatPtr(75),
+						ProbabilityOfPrecipitationPercent: floatPtr(70),
+						WindSpeedMph:                      floatPtr(10),
+						WindGustMph:                       floatPtr(18),
+						WindDirection:                     "S",
+					},
+				},
+			},
+		},
+		{
+			ID:         module.PrecipTiming,
+			StanzaName: string(module.PrecipTiming),
+			Value: briefing.PrecipTimingModule{
+				MaxPopPercent:        intPtr(70),
+				MaxPopTime:           "10 AM",
+				ProbabilityThreshold: 50,
+				PrecipitationWindows: []briefing.PrecipitationWindowModule{
+					{
+						PeriodBegins:  "2026-05-29 at 10:00 AM",
+						PeriodEnds:    "2026-05-29 at 12:00 PM",
+						MaxPopPercent: intPtr(70),
+						MaxPopTime:    "10 AM",
+					},
+				},
+				ThunderMentioned: true,
+			},
+		},
+		{
+			ID:         module.AlertDigest,
+			StanzaName: string(module.AlertDigest),
+			Value: briefing.AlertDigestModule{
+				Checked:       true,
+				ActiveCount:   1,
+				RelevantCount: 1,
+				Relevant: []briefing.AlertSummary{
+					{Event: "Flood Watch", Headline: "Flood Watch until early afternoon", Severity: "Moderate"},
+				},
+			},
+		},
+		{
+			ID:         module.SPCConvectiveOutlooks,
+			StanzaName: string(module.SPCConvectiveOutlooks),
+			Value: briefing.SPCConvectiveOutlooksModule{
+				Checked:      true,
+				OutlookCount: 1,
+				Outlooks: []briefing.SPCConvectiveOutlookRecord{
+					{
+						Label:        "SLGT",
+						LabelText:    "Slight Risk",
+						PeriodBegins: "2026-05-29 at 7:00 AM",
+						PeriodEnds:   "2026-05-29 at 3:00 PM",
+					},
+				},
+			},
+		},
+		{
+			ID:         module.AreaForecastDiscussion,
+			StanzaName: string(module.AreaForecastDiscussion),
+			Value: briefing.AreaForecastDiscussionModule{
+				KeyMessages: []string{"Storms are most likely late morning."},
+				ShortTerm:   "Short-term discussion favors increasing rain coverage.",
+			},
+		},
+		{
+			ID:         module.SPCConvectiveDiscussion,
+			StanzaName: string(module.SPCConvectiveDiscussion),
+			Value: briefing.SPCConvectiveDiscussionModule{
+				IncludedBecause: "categorical severity_rank >= 3",
+				Discussions: []briefing.SPCConvectiveDiscussionRecord{
+					{Headline: "Mesoscale discussion", Summary: "Strong storms may develop late morning."},
+				},
+			},
+		},
+		{
+			ID:         module.WeatherStory,
+			StanzaName: string(module.WeatherStory),
+			Value: briefing.WeatherStoryModule{
+				Available:   true,
+				Title:       "Morning storms",
+				Description: "Morning storms remain the main story.",
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("NewSnapshot() error = %v", err)
+	}
+	return snapshot
+}
+
+func floatPtr(value float64) *float64 {
+	return &value
+}
+
+func intPtr(value int) *int {
+	return &value
+}