Update wind direction and precipitation window presentation

internal/briefing/base_modules_test.go

@@ -64,16 +64,22 @@ func TestNarrativeForecastModuleUsesValidPeriodNarrativePeriods(t *testing.T) {
 	if period.IsDay == nil || !*period.IsDay || period.TemperatureF == nil || *period.TemperatureF != 81 || period.ProbabilityOfPrecipitationPercent == nil || *period.ProbabilityOfPrecipitationPercent != 60 {
 		t.Fatalf("NarrativeForecast period = %#v, want day, temperature, and precip values", period)
 	}
+	if period.WindDirection != "NE" {
+		t.Fatalf("NarrativeForecast period wind direction = %q, want NE", period.WindDirection)
+	}
 	data, err := json.Marshal(output.Value)
 	if err != nil {
 		t.Fatalf("Marshal narrative forecast: %v", err)
 	}
 	jsonText := string(data)
-	for _, field := range []string{"source_location_id", "text_description", "temperature_f", "wind_speed_mph", "probability_of_precipitation_percent"} {
+	for _, field := range []string{"source_location_id", "text_description", "temperature_f", "wind_speed_mph", "wind_direction", "probability_of_precipitation_percent"} {
 		if !strings.Contains(jsonText, field) {
 			t.Fatalf("narrative json = %s, want field %s", jsonText, field)
 		}
 	}
+	if strings.Contains(jsonText, "wind_direction_degrees") {
+		t.Fatalf("narrative json = %s, want compass wind_direction without degrees field", jsonText)
+	}
 	if strings.Contains(jsonText, "Tomorrow night") {
 		t.Fatalf("narrative json = %s, want only valid-period narrative periods", jsonText)
 	}
@@ -133,16 +139,22 @@ func TestCurrentConditionsModuleUsesSnakeCaseUnitFields(t *testing.T) {
 	if value.ConditionText != "Partly cloudy" || value.TemperatureF == nil || *value.TemperatureF != 74 {
 		t.Fatalf("CurrentConditions = %#v, want current condition facts", value)
 	}
+	if value.WindDirection != "S" {
+		t.Fatalf("WindDirection = %q, want S", value.WindDirection)
+	}
 	data, err := json.Marshal(output.Value)
 	if err != nil {
 		t.Fatalf("Marshal current conditions: %v", err)
 	}
 	jsonText := string(data)
-	for _, field := range []string{"condition_text", "temperature_f", "apparent_temperature_f", "relative_humidity_percent", "wind_speed_mph"} {
+	for _, field := range []string{"condition_text", "temperature_f", "apparent_temperature_f", "relative_humidity_percent", "wind_speed_mph", "wind_direction"} {
 		if !strings.Contains(jsonText, field) {
 			t.Fatalf("current json = %s, want field %s", jsonText, field)
 		}
 	}
+	if strings.Contains(jsonText, "wind_direction_degrees") {
+		t.Fatalf("current json = %s, want compass wind_direction without degrees field", jsonText)
+	}
 }
 
 func TestAlertDigestDistinguishesCheckedEmptyAndMissing(t *testing.T) {
@@ -263,6 +275,7 @@ func testModuleContext() ModuleContext {
 	narrativeTempF := 81.0
 	narrativePop := 60.0
 	narrativeWind := 12.0
+	narrativeWindDirection := 45.0
 	updatedAt := mustParseModuleTime("2026-05-29T07:30:00-05:00")
 	return ModuleContext{
 		Resolved: resolved,
@@ -291,6 +304,7 @@ func testModuleContext() ModuleContext {
 						TextDescription:                   "Morning storms, then partly sunny.",
 						TemperatureF:                      floatPtr(narrativeTempF),
 						WindSpeedMph:                      &narrativeWind,
+						WindDirectionDegrees:              &narrativeWindDirection,
 						ProbabilityOfPrecipitationPercent: &narrativePop,
 					},
 				},
@@ -336,6 +350,7 @@ func testModuleContext() ModuleContext {
 					TextDescription:                   "Morning storms, then partly sunny.",
 					TemperatureF:                      floatPtr(narrativeTempF),
 					WindSpeedMph:                      &narrativeWind,
+					WindDirectionDegrees:              &narrativeWindDirection,
 					ProbabilityOfPrecipitationPercent: &narrativePop,
 				},
 			},

internal/briefing/current_conditions_module.go

@@ -14,7 +14,7 @@ type CurrentConditionsModule struct {
 	RelativeHumidityPercent *float64 `json:"relative_humidity_percent,omitempty"`
 	WindSpeedKmh            *float64 `json:"wind_speed_kmh,omitempty"`
 	WindSpeedMph            *float64 `json:"wind_speed_mph,omitempty"`
-	WindDirectionDegrees    *float64 `json:"wind_direction_degrees,omitempty"`
+	WindDirection           string   `json:"wind_direction,omitempty"`
 }
 
 func buildCurrentConditionsModule(ctx ModuleContext, _ any) (*module.Output, error) {
@@ -34,7 +34,7 @@ func buildCurrentConditionsModule(ctx ModuleContext, _ any) (*module.Output, err
 		RelativeHumidityPercent: copyFloat(current.RelativeHumidityPercent),
 		WindSpeedKmh:            copyFloat(current.WindSpeedKmh),
 		WindSpeedMph:            copyFloat(current.WindSpeedMph),
-		WindDirectionDegrees:    copyFloat(current.WindDirectionDegrees),
+		WindDirection:           windDirectionLabel(current.WindDirectionDegrees),
 	}
 	if value.isEmpty() {
 		return nil, nil
@@ -54,5 +54,5 @@ func (v CurrentConditionsModule) isEmpty() bool {
 		v.RelativeHumidityPercent == nil &&
 		v.WindSpeedKmh == nil &&
 		v.WindSpeedMph == nil &&
-		v.WindDirectionDegrees == nil
+		v.WindDirection == ""
 }

internal/briefing/derived_modules_test.go

@@ -30,8 +30,8 @@ func TestDerivedDailySummaryModulePackagesOrdinaryForecast(t *testing.T) {
 	if value.MaxPopPercent == nil || *value.MaxPopPercent != 80 || value.MaxPopWindow != "12 PM-6 PM" {
 		t.Fatalf("max precip = %#v %q, want 80 and afternoon window", value.MaxPopPercent, value.MaxPopWindow)
 	}
-	if value.FirstPrecipHour != "8 AM" || value.LastPrecipHour != "1 PM" || !value.ThunderMentioned {
+	if value.FirstPrecipHour != "8 AM" || value.LastPrecipHour != "2 PM" || !value.ThunderMentioned {
-		t.Fatalf("precip timing = %#v, want morning through afternoon thunder", value)
+		t.Fatalf("precip timing = %#v, want threshold windows from morning through afternoon thunder", value)
 	}
 	if value.MaxWindGustMph == nil || *value.MaxWindGustMph != 42 {
 		t.Fatalf("MaxWindGustMph = %#v, want 42", value.MaxWindGustMph)
@@ -63,8 +63,27 @@ func TestPrecipTimingModuleHandlesRainyAndDryForecasts(t *testing.T) {
 		t.Fatalf("BuildModule(rainy) error = %v", err)
 	}
 	rainy := moduleValue[PrecipTimingModule](t, output)
-	if rainy.MaxPopPercent == nil || *rainy.MaxPopPercent != 80 || rainy.FirstPrecipHour != "8 AM" || rainy.LastPrecipHour != "1 PM" || !rainy.ThunderMentioned {
+	if rainy.MaxPopPercent == nil || *rainy.MaxPopPercent != 80 || rainy.MaxPopTime != "12 PM" || rainy.ProbabilityThreshold != forecast.DefaultPrecipWindowProbabilityThreshold || !rainy.ThunderMentioned {
-		t.Fatalf("rainy precip timing = %#v, want peak, first/last, thunder", rainy)
+		t.Fatalf("rainy precip timing = %#v, want peak, threshold, and thunder", rainy)
+	}
+	if len(rainy.PrecipitationWindows) != 2 {
+		t.Fatalf("rainy precipitation windows = %#v, want two windows", rainy.PrecipitationWindows)
+	}
+	if rainy.PrecipitationWindows[0].Start != "8 AM" || rainy.PrecipitationWindows[0].End != "9 AM" || rainy.PrecipitationWindows[0].MaxPopPercent == nil || *rainy.PrecipitationWindows[0].MaxPopPercent != 60 {
+		t.Fatalf("first precipitation window = %#v, want 8-9 AM at 60%%", rainy.PrecipitationWindows[0])
+	}
+	if rainy.PrecipitationWindows[1].Start != "12 PM" || rainy.PrecipitationWindows[1].End != "2 PM" || rainy.PrecipitationWindows[1].MaxPopPercent == nil || *rainy.PrecipitationWindows[1].MaxPopPercent != 80 {
+		t.Fatalf("second precipitation window = %#v, want noon-2 PM at 80%%", rainy.PrecipitationWindows[1])
+	}
+	data, err := json.Marshal(output.Value)
+	if err != nil {
+		t.Fatalf("marshal precip timing: %v", err)
+	}
+	if !strings.Contains(string(data), "precipitation_windows") || !strings.Contains(string(data), "probability_threshold") {
+		t.Fatalf("precip timing json = %s, want threshold and windows", string(data))
+	}
+	if strings.Contains(string(data), "first_precip_hour") || strings.Contains(string(data), "last_precip_hour") {
+		t.Fatalf("precip timing json = %s, want no ambiguous first/last fields", string(data))
 	}
 
 	ctx.Derived.PrecipTiming = forecast.BuildPrecipTiming([]weatherdata.ForecastPeriod{derivedHour("2026-05-29T10:00:00-05:00", "Sunny", 0, 70, nil, 5)})
@@ -73,8 +92,8 @@ func TestPrecipTimingModuleHandlesRainyAndDryForecasts(t *testing.T) {
 		t.Fatalf("BuildModule(dry) error = %v", err)
 	}
 	dry := moduleValue[PrecipTimingModule](t, output)
-	if dry.FirstPrecipHour != "" || dry.LastPrecipHour != "" || dry.ThunderMentioned {
+	if len(dry.PrecipitationWindows) != 0 || dry.ThunderMentioned {
-		t.Fatalf("dry precip timing = %#v, want no precip hours and no thunder", dry)
+		t.Fatalf("dry precip timing = %#v, want no precip windows and no thunder", dry)
 	}
 	if dry.MaxPopPercent == nil || *dry.MaxPopPercent != 0 {
 		t.Fatalf("dry MaxPopPercent = %#v, want checked zero", dry.MaxPopPercent)
@@ -191,8 +210,10 @@ func derivedModuleContext(id report.ID) ModuleContext {
 	hours := []weatherdata.ForecastPeriod{
 		derivedHour("2026-05-29T00:00:00-05:00", "Clear and cold", 0, 31, nil, 5),
 		derivedHour("2026-05-29T08:00:00-05:00", "Showers", 60, 58, nil, 15),
+		derivedHour("2026-05-29T09:00:00-05:00", "Dry break", 20, 62, nil, 10),
 		derivedHour("2026-05-29T12:00:00-05:00", "Thunderstorms with gusty wind", 80, 96, floatPtr(101), 42),
 		derivedHour("2026-05-29T13:00:00-05:00", "Heavy rain", 70, 82, nil, 30),
+		derivedHour("2026-05-29T14:00:00-05:00", "Drying out", 20, 78, nil, 12),
 	}
 	narrative := []weatherdata.ForecastPeriod{
 		{

internal/briefing/module_format_helpers.go

@@ -2,6 +2,7 @@ package briefing
 
 import (
 	"fmt"
+	"math"
 	"time"
 
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/forecast"
@@ -46,6 +47,19 @@ func roundedInt(value *float64) *int {
 	return &rounded
 }
 
+func windDirectionLabel(degrees *float64) string {
+	if degrees == nil {
+		return ""
+	}
+	labels := []string{"N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE", "S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW"}
+	normalized := math.Mod(*degrees, 360)
+	if normalized < 0 {
+		normalized += 360
+	}
+	sector := int(math.Floor((normalized+11.25)/22.5)) % len(labels)
+	return labels[sector]
+}
+
 func timedClockLabel(value *forecast.TimedValue, timezone string) string {
 	if value == nil {
 		return ""

internal/briefing/module_format_helpers_test.go

@@ -0,0 +1,29 @@
+package briefing
+
+import "testing"
+
+func TestWindDirectionLabelUsesSixteenPointCompass(t *testing.T) {
+	tests := []struct {
+		name    string
+		degrees *float64
+		want    string
+	}{
+		{name: "nil", degrees: nil, want: ""},
+		{name: "north", degrees: floatPtr(0), want: "N"},
+		{name: "below first boundary", degrees: floatPtr(11.24), want: "N"},
+		{name: "at first boundary", degrees: floatPtr(11.25), want: "NNE"},
+		{name: "northeast", degrees: floatPtr(45), want: "NE"},
+		{name: "south", degrees: floatPtr(180), want: "S"},
+		{name: "wrap to north", degrees: floatPtr(348.75), want: "N"},
+		{name: "full rotation", degrees: floatPtr(360), want: "N"},
+		{name: "negative normalizes", degrees: floatPtr(-45), want: "NW"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := windDirectionLabel(tt.degrees); got != tt.want {
+				t.Fatalf("windDirectionLabel(%v) = %q, want %q", tt.degrees, got, tt.want)
+			}
+		})
+	}
+}

internal/briefing/narrative_forecast_module.go

@@ -32,7 +32,7 @@ type NarrativeForecastPeriod struct {
 	WindSpeedMph                      *float64  `json:"wind_speed_mph,omitempty"`
 	WindGustKmh                       *float64  `json:"wind_gust_kmh,omitempty"`
 	WindGustMph                       *float64  `json:"wind_gust_mph,omitempty"`
-	WindDirectionDegrees              *float64  `json:"wind_direction_degrees,omitempty"`
+	WindDirection                     string    `json:"wind_direction,omitempty"`
 	ProbabilityOfPrecipitationPercent *float64  `json:"probability_of_precipitation_percent,omitempty"`
 }
 
@@ -74,7 +74,7 @@ func narrativeForecastPeriods(periods []weatherdata.ForecastPeriod) []NarrativeF
 			WindSpeedMph:                      copyFloat(period.WindSpeedMph),
 			WindGustKmh:                       copyFloat(period.WindGustKmh),
 			WindGustMph:                       copyFloat(period.WindGustMph),
-			WindDirectionDegrees:              copyFloat(period.WindDirectionDegrees),
+			WindDirection:                     windDirectionLabel(period.WindDirectionDegrees),
 			ProbabilityOfPrecipitationPercent: copyFloat(period.ProbabilityOfPrecipitationPercent),
 		})
 	}

internal/briefing/precip_timing_module.go

@@ -8,23 +8,42 @@ import (
 type PrecipTimingModule struct {
 	MaxPopPercent        *int                        `json:"max_pop_percent,omitempty"`
 	MaxPopTime           string                      `json:"max_pop_time,omitempty"`
-	FirstPrecipHour  string `json:"first_precip_hour,omitempty"`
+	ProbabilityThreshold float64                     `json:"probability_threshold"`
-	LastPrecipHour   string `json:"last_precip_hour,omitempty"`
+	PrecipitationWindows []PrecipitationWindowModule `json:"precipitation_windows,omitempty"`
 	ThunderMentioned     bool                        `json:"thunder_mentioned"`
 }
 
+type PrecipitationWindowModule struct {
+	Start         string `json:"start"`
+	End           string `json:"end,omitempty"`
+	MaxPopPercent *int   `json:"max_pop_percent,omitempty"`
+	MaxPopTime    string `json:"max_pop_time,omitempty"`
+}
+
 func buildPrecipTimingModule(ctx ModuleContext, _ any) (*module.Output, error) {
 	value := precipTimingValue(ctx.Derived.PrecipTiming, ctx.Timezone)
 	return &module.Output{ID: module.PrecipTiming, StanzaName: "precip_timing", Value: value}, nil
 }
 
 func precipTimingValue(timing forecast.PrecipTiming, timezone string) PrecipTimingModule {
-	value := PrecipTimingModule{ThunderMentioned: timing.ThunderMentioned}
+	value := PrecipTimingModule{
+		ProbabilityThreshold: timing.ProbabilityThreshold,
+		ThunderMentioned:     timing.ThunderMentioned,
+	}
 	if timing.MaxPrecipitationProbability != nil {
 		value.MaxPopPercent = roundedInt(&timing.MaxPrecipitationProbability.Value)
 		value.MaxPopTime = clockLabel(timing.MaxPrecipitationProbability.Time, timezone)
 	}
-	value.FirstPrecipHour = timedClockLabel(timing.FirstPrecipitation, timezone)
+	for _, window := range timing.PrecipitationWindows {
-	value.LastPrecipHour = timedClockLabel(timing.LastPrecipitation, timezone)
+		item := PrecipitationWindowModule{
+			Start: clockLabel(window.Start, timezone),
+		}
+		if window.End != nil {
+			item.End = clockLabel(*window.End, timezone)
+		}
+		item.MaxPopPercent = roundedInt(&window.MaxPrecipitationProbability.Value)
+		item.MaxPopTime = clockLabel(window.MaxPrecipitationProbability.Time, timezone)
+		value.PrecipitationWindows = append(value.PrecipitationWindows, item)
+	}
 	return value
 }

internal/facts/facts_test.go

@@ -69,6 +69,12 @@ func TestBuildDerivedDailySlicesDaypartsAndAlerts(t *testing.T) {
 	if derived.PrecipTiming.FirstPrecipitation == nil || derived.PrecipTiming.FirstPrecipitation.Time.Format(time.RFC3339) != "2026-05-29T08:00:00-05:00" {
 		t.Fatalf("PrecipTiming.FirstPrecipitation = %#v, want valid-period rain start", derived.PrecipTiming.FirstPrecipitation)
 	}
+	if derived.PrecipTiming.LastPrecipitation == nil || derived.PrecipTiming.LastPrecipitation.Time.Format(time.RFC3339) != "2026-05-29T14:00:00-05:00" {
+		t.Fatalf("PrecipTiming.LastPrecipitation = %#v, want final closed window end", derived.PrecipTiming.LastPrecipitation)
+	}
+	if len(derived.PrecipTiming.PrecipitationWindows) != 2 {
+		t.Fatalf("PrecipitationWindows = %#v, want two threshold windows", derived.PrecipTiming.PrecipitationWindows)
+	}
 	if !derived.PrecipTiming.ThunderMentioned {
 		t.Fatal("PrecipTiming.ThunderMentioned = false, want true")
 	}

internal/forecast/derive.go

@@ -47,6 +47,8 @@ type TimedValue struct {
 	Time  time.Time `json:"time"`
 }
 
+const DefaultPrecipWindowProbabilityThreshold = 40
+
 type Indicators struct {
 	Snow bool `json:"snow,omitempty"`
 	Ice  bool `json:"ice,omitempty"`
@@ -69,31 +71,98 @@ type PrecipTiming struct {
 	MaxPrecipitationProbability *TimedValue           `json:"maxPrecipitationProbability,omitempty"`
 	FirstPrecipitation          *TimedValue           `json:"firstPrecipitation,omitempty"`
 	LastPrecipitation           *TimedValue           `json:"lastPrecipitation,omitempty"`
+	ProbabilityThreshold        float64               `json:"probabilityThreshold"`
+	PrecipitationWindows        []PrecipitationWindow `json:"precipitationWindows,omitempty"`
 	ThunderMentioned            bool                  `json:"thunderMentioned,omitempty"`
 }
 
+type PrecipitationWindow struct {
+	Start                       time.Time  `json:"start"`
+	End                         *time.Time `json:"end,omitempty"`
+	MaxPrecipitationProbability TimedValue `json:"maxPrecipitationProbability"`
+	ProbabilityThreshold        float64    `json:"probabilityThreshold"`
+}
+
 func BuildPrecipTiming(periods []weatherdata.ForecastPeriod) PrecipTiming {
-	var timing PrecipTiming
+	return buildPrecipTimingWithThreshold(periods, DefaultPrecipWindowProbabilityThreshold)
-	for _, forecastPeriod := range periods {
+}
-		setMaxTimedValue(&timing.MaxPrecipitationProbability, forecastPeriod.ProbabilityOfPrecipitationPercent, forecastPeriod.StartTime)
+
-		if forecastPeriod.ProbabilityOfPrecipitationPercent != nil && *forecastPeriod.ProbabilityOfPrecipitationPercent > 0 {
+func buildPrecipTimingWithThreshold(periods []weatherdata.ForecastPeriod, threshold float64) PrecipTiming {
-			value := TimedValue{
+	timing := PrecipTiming{ProbabilityThreshold: threshold}
-				Value: *forecastPeriod.ProbabilityOfPrecipitationPercent,
+	sorted := append([]weatherdata.ForecastPeriod(nil), periods...)
+	sort.SliceStable(sorted, func(i int, j int) bool {
+		return sorted[i].StartTime.Before(sorted[j].StartTime)
+	})
+
+	var active *PrecipitationWindow
+	var activeLastEnd time.Time
+	closeActive := func() {
+		if active == nil {
+			return
+		}
+		end := activeLastEnd
+		active.End = &end
+		timing.PrecipitationWindows = append(timing.PrecipitationWindows, *active)
+		active = nil
+	}
+	startActive := func(forecastPeriod weatherdata.ForecastPeriod, probability float64) {
+		active = &PrecipitationWindow{
+			Start: forecastPeriod.StartTime,
+			MaxPrecipitationProbability: TimedValue{
+				Value: probability,
+				Time:  forecastPeriod.StartTime,
+			},
+			ProbabilityThreshold: threshold,
+		}
+		activeLastEnd = forecastPeriod.EndTime
+		if timing.FirstPrecipitation == nil {
+			timing.FirstPrecipitation = &TimedValue{
+				Value: probability,
 				Time:  forecastPeriod.StartTime,
 			}
-			if timing.FirstPrecipitation == nil || value.Time.Before(timing.FirstPrecipitation.Time) {
-				copied := value
-				timing.FirstPrecipitation = &copied
 		}
-			if timing.LastPrecipitation == nil || value.Time.After(timing.LastPrecipitation.Time) {
+	}
-				copied := value
+
-				timing.LastPrecipitation = &copied
+	for _, forecastPeriod := range sorted {
+		setMaxTimedValue(&timing.MaxPrecipitationProbability, forecastPeriod.ProbabilityOfPrecipitationPercent, forecastPeriod.StartTime)
+		if forecastPeriod.ProbabilityOfPrecipitationPercent == nil || *forecastPeriod.ProbabilityOfPrecipitationPercent < threshold {
+			closeActive()
+		} else {
+			probability := *forecastPeriod.ProbabilityOfPrecipitationPercent
+			if active == nil {
+				startActive(forecastPeriod, probability)
+			} else {
+				if forecastPeriod.StartTime.After(activeLastEnd) {
+					closeActive()
+					startActive(forecastPeriod, probability)
+				}
+				if probability > active.MaxPrecipitationProbability.Value {
+					active.MaxPrecipitationProbability = TimedValue{
+						Value: probability,
+						Time:  forecastPeriod.StartTime,
+					}
+				}
+				if forecastPeriod.EndTime.After(activeLastEnd) {
+					activeLastEnd = forecastPeriod.EndTime
+				}
 			}
 		}
 		if mentionsThunder(forecastPeriod.TextDescription) {
 			timing.ThunderMentioned = true
 		}
 	}
+	if active != nil {
+		timing.PrecipitationWindows = append(timing.PrecipitationWindows, *active)
+	}
+	if len(timing.PrecipitationWindows) > 0 {
+		final := timing.PrecipitationWindows[len(timing.PrecipitationWindows)-1]
+		if final.End != nil {
+			timing.LastPrecipitation = &TimedValue{
+				Value: final.MaxPrecipitationProbability.Value,
+				Time:  *final.End,
+			}
+		}
+	}
 	return timing
 }
 

internal/forecast/derive_test.go

@@ -210,31 +210,94 @@ func TestAlertOverlap(t *testing.T) {
 	}
 }
 
-func TestBuildPrecipTimingTracksRainAndThunder(t *testing.T) {
+func TestBuildPrecipTimingBuildsThresholdWindows(t *testing.T) {
 	location := time.FixedZone("Test", -5*60*60)
 	periods := []weatherdata.ForecastPeriod{
 		hour(location, "2026-05-29T08:00:00-05:00", "2026-05-29T09:00:00-05:00", "Cloudy", 70, nil, ptr(0), nil, nil),
-		hour(location, "2026-05-29T09:00:00-05:00", "2026-05-29T10:00:00-05:00", "Showers", 70, nil, ptr(30), nil, nil),
 		hour(location, "2026-05-29T12:00:00-05:00", "2026-05-29T13:00:00-05:00", "Thunderstorms", 70, nil, ptr(80), nil, nil),
-		hour(location, "2026-05-29T18:00:00-05:00", "2026-05-29T19:00:00-05:00", "Dry", 70, nil, ptr(0), nil, nil),
+		hour(location, "2026-05-29T11:00:00-05:00", "2026-05-29T12:00:00-05:00", "Brief lull", 70, nil, ptr(39.999), nil, nil),
+		hour(location, "2026-05-29T13:00:00-05:00", "2026-05-29T14:00:00-05:00", "Unknown rain chance", 70, nil, nil, nil, nil),
+		hour(location, "2026-05-29T10:00:00-05:00", "2026-05-29T11:00:00-05:00", "Rain likely", 70, nil, ptr(60), nil, nil),
+		hour(location, "2026-05-29T09:00:00-05:00", "2026-05-29T10:00:00-05:00", "Showers", 70, nil, ptr(40), nil, nil),
 	}
 
 	timing := BuildPrecipTiming(periods)
 
 	if timing.FirstPrecipitation == nil || timing.FirstPrecipitation.Time.Format(time.RFC3339) != "2026-05-29T09:00:00-05:00" {
-		t.Fatalf("FirstPrecipitation = %#v, want 9 AM shower", timing.FirstPrecipitation)
+		t.Fatalf("FirstPrecipitation = %#v, want first threshold window start", timing.FirstPrecipitation)
 	}
-	if timing.LastPrecipitation == nil || timing.LastPrecipitation.Time.Format(time.RFC3339) != "2026-05-29T12:00:00-05:00" {
+	if timing.LastPrecipitation == nil || timing.LastPrecipitation.Time.Format(time.RFC3339) != "2026-05-29T13:00:00-05:00" {
-		t.Fatalf("LastPrecipitation = %#v, want noon thunderstorm", timing.LastPrecipitation)
+		t.Fatalf("LastPrecipitation = %#v, want final closed threshold window end", timing.LastPrecipitation)
 	}
 	if timing.MaxPrecipitationProbability == nil || timing.MaxPrecipitationProbability.Value != 80 {
 		t.Fatalf("MaxPrecipitationProbability = %#v, want 80", timing.MaxPrecipitationProbability)
 	}
+	if timing.ProbabilityThreshold != DefaultPrecipWindowProbabilityThreshold {
+		t.Fatalf("ProbabilityThreshold = %v, want default threshold", timing.ProbabilityThreshold)
+	}
+	if len(timing.PrecipitationWindows) != 2 {
+		t.Fatalf("PrecipitationWindows length = %d, want 2: %#v", len(timing.PrecipitationWindows), timing.PrecipitationWindows)
+	}
+	first := timing.PrecipitationWindows[0]
+	if first.Start.Format(time.RFC3339) != "2026-05-29T09:00:00-05:00" || first.End == nil || first.End.Format(time.RFC3339) != "2026-05-29T11:00:00-05:00" {
+		t.Fatalf("first window = %#v, want 9-11 AM", first)
+	}
+	if first.MaxPrecipitationProbability.Value != 60 || first.MaxPrecipitationProbability.Time.Format(time.RFC3339) != "2026-05-29T10:00:00-05:00" {
+		t.Fatalf("first window max = %#v, want 60 at 10 AM", first.MaxPrecipitationProbability)
+	}
+	second := timing.PrecipitationWindows[1]
+	if second.Start.Format(time.RFC3339) != "2026-05-29T12:00:00-05:00" || second.End == nil || second.End.Format(time.RFC3339) != "2026-05-29T13:00:00-05:00" {
+		t.Fatalf("second window = %#v, want noon-1 PM", second)
+	}
 	if !timing.ThunderMentioned {
 		t.Fatal("ThunderMentioned = false, want true")
 	}
 }
 
+func TestBuildPrecipTimingLeavesFinalWindowOpen(t *testing.T) {
+	location := time.FixedZone("Test", -5*60*60)
+	periods := []weatherdata.ForecastPeriod{
+		hour(location, "2026-05-29T08:00:00-05:00", "2026-05-29T09:00:00-05:00", "Cloudy", 70, nil, ptr(0), nil, nil),
+		hour(location, "2026-05-29T09:00:00-05:00", "2026-05-29T10:00:00-05:00", "Showers", 70, nil, ptr(45), nil, nil),
+		hour(location, "2026-05-29T10:00:00-05:00", "2026-05-29T11:00:00-05:00", "Rain likely", 70, nil, ptr(60), nil, nil),
+	}
+
+	timing := BuildPrecipTiming(periods)
+
+	if len(timing.PrecipitationWindows) != 1 {
+		t.Fatalf("PrecipitationWindows length = %d, want 1", len(timing.PrecipitationWindows))
+	}
+	if timing.PrecipitationWindows[0].End != nil {
+		t.Fatalf("open window End = %v, want nil", timing.PrecipitationWindows[0].End)
+	}
+	if timing.LastPrecipitation != nil {
+		t.Fatalf("LastPrecipitation = %#v, want nil for open final window", timing.LastPrecipitation)
+	}
+}
+
+func TestBuildPrecipTimingSupportsNonDefaultThreshold(t *testing.T) {
+	location := time.FixedZone("Test", -5*60*60)
+	periods := []weatherdata.ForecastPeriod{
+		hour(location, "2026-05-29T08:00:00-05:00", "2026-05-29T09:00:00-05:00", "Showers", 70, nil, ptr(50), nil, nil),
+		hour(location, "2026-05-29T09:00:00-05:00", "2026-05-29T10:00:00-05:00", "Rain likely", 70, nil, ptr(60), nil, nil),
+		hour(location, "2026-05-29T10:00:00-05:00", "2026-05-29T11:00:00-05:00", "Showers", 70, nil, ptr(55), nil, nil),
+		hour(location, "2026-05-29T11:00:00-05:00", "2026-05-29T12:00:00-05:00", "Drying out", 70, nil, ptr(20), nil, nil),
+	}
+
+	timing := buildPrecipTimingWithThreshold(periods, 55)
+
+	if timing.ProbabilityThreshold != 55 {
+		t.Fatalf("ProbabilityThreshold = %v, want 55", timing.ProbabilityThreshold)
+	}
+	if len(timing.PrecipitationWindows) != 1 {
+		t.Fatalf("PrecipitationWindows length = %d, want 1", len(timing.PrecipitationWindows))
+	}
+	window := timing.PrecipitationWindows[0]
+	if window.Start.Format(time.RFC3339) != "2026-05-29T09:00:00-05:00" || window.End == nil || window.End.Format(time.RFC3339) != "2026-05-29T11:00:00-05:00" {
+		t.Fatalf("window = %#v, want 9-11 AM", window)
+	}
+}
+
 func TestBuildPrecipTimingHandlesDryForecast(t *testing.T) {
 	location := time.FixedZone("Test", -5*60*60)
 	periods := []weatherdata.ForecastPeriod{
@@ -243,9 +306,12 @@ func TestBuildPrecipTimingHandlesDryForecast(t *testing.T) {
 
 	timing := BuildPrecipTiming(periods)
 
-	if timing.FirstPrecipitation != nil || timing.LastPrecipitation != nil || timing.ThunderMentioned {
+	if timing.FirstPrecipitation != nil || timing.LastPrecipitation != nil || len(timing.PrecipitationWindows) != 0 || timing.ThunderMentioned {
 		t.Fatalf("dry timing = %#v, want no precip timing and no thunder", timing)
 	}
+	if timing.ProbabilityThreshold != DefaultPrecipWindowProbabilityThreshold {
+		t.Fatalf("ProbabilityThreshold = %v, want default threshold", timing.ProbabilityThreshold)
+	}
 	if timing.MaxPrecipitationProbability == nil || timing.MaxPrecipitationProbability.Value != 0 {
 		t.Fatalf("dry max precip = %#v, want checked zero chance", timing.MaxPrecipitationProbability)
 	}