diff --git a/SleepFocus/Models/HomeSummary.swift b/SleepFocus/Models/HomeSummary.swift
index 5c51285..0edbc5e 100644
--- a/SleepFocus/Models/HomeSummary.swift
+++ b/SleepFocus/Models/HomeSummary.swift
@@ -17,7 +17,7 @@ nonisolated struct HomeSummaryMonthPayload: Decodable {
     let updatedAt: String
 }
 
-nonisolated struct HomeSummary: Decodable {
+nonisolated struct HomeSummary: Codable {
     let userId: String
     let selectedDate: String?
     let sleepQuality: SleepQualitySummary
@@ -29,25 +29,25 @@ nonisolated struct HomeSummary: Decodable {
     let processing: ProcessingSummary?
 }
 
-nonisolated struct SleepQualitySummary: Decodable {
+nonisolated struct SleepQualitySummary: Codable {
     let score: Double?
     let maxScore: Double?
     let status: String?
     let source: String?
 }
 
-nonisolated struct FocusPredictionSummary: Decodable {
+nonisolated struct FocusPredictionSummary: Codable {
     let score: Int?
     let label: String?
     let source: String?
 }
 
-nonisolated struct CircadianRhythmSummary: Decodable {
+nonisolated struct CircadianRhythmSummary: Codable {
     let averageWakeTimeMinutes: Int
     let confidence: Double
 }
 
-nonisolated struct ProcessingSummary: Decodable {
+nonisolated struct ProcessingSummary: Codable {
     let state: String
     let lastJobId: String?
     let updatedAt: String?
diff --git a/SleepFocus/Services/HomeSummaryStore.swift b/SleepFocus/Services/HomeSummaryStore.swift
index 51a41ee..33cdfa3 100644
--- a/SleepFocus/Services/HomeSummaryStore.swift
+++ b/SleepFocus/Services/HomeSummaryStore.swift
@@ -34,7 +34,7 @@ final class HomeSummaryStore: ObservableObject {
 
         isWaitingForModel = false
         isSyncing = false
-        summary = monthSummariesByDay[selectedMonthKey]?[selectedDayKey]
+        summary = monthSummariesByDay[selectedMonthKey]?[selectedDayKey] ?? loadPersistedSummary(for: selectedDayKey)
         sleepMetrics = nil
         sleepStageBreakdown = nil
 
@@ -56,6 +56,7 @@ final class HomeSummaryStore: ObservableObject {
         var resolvedSummary = monthSummariesByDay[selectedMonthKey]?[selectedDayKey]
         if let resolvedSummary {
             summary = resolvedSummary
+            cacheSummary(resolvedSummary, fallbackDate: selectedDate)
         }
 
         if resolvedSummary == nil {
@@ -195,6 +196,25 @@ final class HomeSummaryStore: ObservableObject {
         var monthMap = monthSummariesByDay[monthKey] ?? [:]
         monthMap[dayKey] = summary
         monthSummariesByDay[monthKey] = monthMap
+
+        persistSummary(summary, for: dayKey)
+    }
+
+    private func loadPersistedSummary(for dayKey: String) -> HomeSummary? {
+        guard let data = UserDefaults.standard.data(forKey: Self.persistenceKey(for: dayKey)),
+              let decoded = try? JSONDecoder().decode(HomeSummary.self, from: data) else {
+            return nil
+        }
+        return decoded
+    }
+
+    private func persistSummary(_ summary: HomeSummary, for dayKey: String) {
+        guard let data = try? JSONEncoder().encode(summary) else { return }
+        UserDefaults.standard.set(data, forKey: Self.persistenceKey(for: dayKey))
+    }
+
+    private static func persistenceKey(for dayKey: String) -> String {
+        "homeSummary.\(dayKey)"
     }
 
     // Ramp up polling to improve fetching performance without spamming backend