diff --git a/src/DaylioData/DaylioData.csproj b/src/DaylioData/DaylioData.csproj
index 392d634..7f5ca21 100644
--- a/src/DaylioData/DaylioData.csproj
+++ b/src/DaylioData/DaylioData.csproj
@@ -14,8 +14,8 @@
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <BaseOutputPath>..\..\BuildResults</BaseOutputPath>
     <UseCommonOutputDirectory>true</UseCommonOutputDirectory>
-    <AssemblyVersion>0.1.4.0</AssemblyVersion>
-    <Version>0.1.4</Version>
+    <AssemblyVersion>0.1.5.0</AssemblyVersion>
+    <Version>0.1.5</Version>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/DaylioData/Methods.cs b/src/DaylioData/Methods.cs
index 9c3bca6..e660cf1 100644
--- a/src/DaylioData/Methods.cs
+++ b/src/DaylioData/Methods.cs
@@ -1,5 +1,4 @@
 using DaylioData.Models;
-using System.Runtime.InteropServices;
 
 namespace DaylioData
 {
@@ -127,12 +126,12 @@ public static void InitData(DaylioData daylioData)
         public static IEnumerable<DaylioCSVDataModel>? GetEntriesWithMood(string mood)
         {
             if (string.IsNullOrWhiteSpace(mood) ||
-                _daylioData?.DataRepo?.Moods.Where(entry => entry.Equals(mood)).Any() == false)
+                _daylioData?.DataRepo?.Moods.Where(entryMoods => entryMoods.Equals(mood)).Any() == false)
             {
                 return null;
             }
 
-            return _daylioData?.DataRepo?.CSVData?.Where(entry => entry.Mood?.Equals(mood, StringComparison.InvariantCultureIgnoreCase) == true);
+            return _daylioData?.DataRepo?.CSVData?.Where(entry => entry.Mood.Equals(mood, StringComparison.InvariantCultureIgnoreCase) == true);
         }
 
         /// <summary>
@@ -162,6 +161,7 @@ public static void InitData(DaylioData daylioData)
         /// <summary>
         /// Gets the number of entries that include a specified activity.
         /// </summary>
+        /// <param name="daylioData">The <see cref="DaylioData"/> instance to use.</param>
         /// <param name="activity">An activity string</param>
         /// <returns>The <see cref="int"/> number of activities that include a specified activity.</returns>
         public static int? GetActivityCount(DaylioData daylioData, string activity)
@@ -185,7 +185,6 @@ public static void InitData(DaylioData daylioData)
 
         /// <summary>
         /// Gets <see cref="DaylioCSVDataModel"/> entries that contain a specified string in the note.
-        /// Assumes that <see cref="DaylioData"/> has been initialized, otherwise returns null.
         /// </summary>
         /// <param name="daylioData">The <see cref="DaylioData"/> instance to use.</param>
         /// <param name="searchString">The <see cref="string"/> to search for within entries.</param>
@@ -196,5 +195,50 @@ public static void InitData(DaylioData daylioData)
             InitData(daylioData);
             return GetEntriesWithString(searchString, comparisonMethod);
         }
+
+        /// <summary>
+        /// Gets an avererage mood rating for a specified activity. Requires levels to be set for each mood.
+        /// Assumes that <see cref="DaylioData"/> has been initialized, otherwise returns null.
+        /// </summary>
+        /// <param name="activity">The activity name to get an avergae mood rating for.</param>
+        /// <returns>An average <see cref="Decimal?"/> mood rating for the specified activity.</returns>
+        public static decimal? GetAverageActivityMood(string activity)
+        {
+            if (_daylioData == null || _daylioData.DataRepo == null || string.IsNullOrWhiteSpace(activity)
+                || !_daylioData.DataRepo.Activities.Contains(activity) || _daylioData.DataRepo.Moods.Where(x => x.Key == null).Any())
+            {
+                return null;
+            }
+
+            uint moodSum = 0;
+            uint count = 0;
+
+            foreach (DaylioCSVDataModel entry in _daylioData.DataRepo.CSVData?.Where(entry => entry.ActivitiesCollection
+                           .Any(entryActivity => entryActivity.Equals(activity, StringComparison.InvariantCultureIgnoreCase)))
+                               ?? Enumerable.Empty<DaylioCSVDataModel>())
+            {
+                if (entry == Enumerable.Empty<DaylioCSVDataModel>())
+                {
+                    continue;
+                }
+                moodSum += Convert.ToUInt32(_daylioData.DataRepo.Moods[entry.Mood]);
+                count++;
+            }
+
+            return count == 0 ? null 
+                : (decimal)moodSum / count;
+        }
+
+        /// <summary>
+        /// Gets an avererage mood rating for a specified activity. Requires levels to be set for each mood.
+        /// </summary>
+        /// <param name="daylioData">The <see cref="DaylioData"/> instance to use.</param>
+        /// <param name="activity">The activity name to get an avergae mood rating for.</param>
+        /// <returns>An average <see cref="Decimal?"/> mood rating for the specified activity.</returns>
+        public static decimal? GetAverageActivityMood(DaylioData daylioData, string activity)
+        {
+            InitData(daylioData);
+            return GetAverageActivityMood(activity);
+        }
     }
-}
+}
\ No newline at end of file
diff --git a/src/DaylioData/Models/DaylioCSVDataModel.cs b/src/DaylioData/Models/DaylioCSVDataModel.cs
index f7b2e98..33b86d4 100644
--- a/src/DaylioData/Models/DaylioCSVDataModel.cs
+++ b/src/DaylioData/Models/DaylioCSVDataModel.cs
@@ -8,19 +8,19 @@ namespace DaylioData.Models
     public class DaylioCSVDataModel
     {
         [Index(0)]
-        public DateOnly FullDate { get; set; }
+        public required DateOnly FullDate { get; set; }
 
         [Index(1)]
-        public DateOnly Date { get; set; }
+        public required DateOnly Date { get; set; }
 
         [Index(2)]
-        public string? Weekday { get; set; }
+        public required string? Weekday { get; set; }
 
         [Index(3)]
-        public TimeOnly Time { get; set; }
+        public required TimeOnly Time { get; set; }
 
         [Index(4)]
-        public string? Mood { get; set; }
+        public required string Mood { get; set; }
 
         [Index(5)]
         public string? Activities { get; set; }
diff --git a/src/DaylioData/Repo/DaylioDataRepo.cs b/src/DaylioData/Repo/DaylioDataRepo.cs
index dd13198..7df24f7 100644
--- a/src/DaylioData/Repo/DaylioDataRepo.cs
+++ b/src/DaylioData/Repo/DaylioDataRepo.cs
@@ -10,10 +10,18 @@ public class DaylioDataRepo
 
         private IEnumerable<DaylioCSVDataModel>? _CSVData;
         private DaylioFileAccess? _fileAccess;
+        private readonly Dictionary<string, short> _defaultMoods = new Dictionary<string, short>()
+        {
+            { "rad", 5 },
+            { "good", 4 },
+            { "meh", 3 },
+            { "bad", 2 },
+            { "awful", 1 }
+        };
 
         public IEnumerable<DaylioCSVDataModel>? CSVData => _CSVData;
         public HashSet<string> Activities = new HashSet<string>();
-        public HashSet<string> Moods = new HashSet<string>();
+        public Dictionary<string, short?> Moods = new Dictionary<string, short?>();
 
         internal DaylioDataRepo(DaylioFileAccess fileAccess)
         {
@@ -33,10 +41,40 @@ public void UpdateFile(string filePath)
             InitializeMoods();
         }
 
+        /// <summary>
+        /// Used to set custom mood levels.
+        /// </summary>
+        /// <param name="moodName">The name of the mood to set a level for.</param>
+        /// <param name="moodLevel">The level to set for the mood.</param>
+        public void SetMoodLevel(string moodName, short? moodLevel)
+        {
+            if (Moods.ContainsKey(moodName))
+            {
+                Moods[moodName] = moodLevel;
+            }
+        }
+
+        /// <summary>
+        /// Sets mood levels based on Daylio's default moods. This cannot be used with custom moods. <br></br>
+        /// Rad - 5, Good - 4, Meh - 3, Bad - 2, Awful - 1
+        /// </summary>
+        /// <exception cref="InvalidOperationException"></exception>
+        public void SetDefaultMoodLevels()
+        {
+            foreach (KeyValuePair<string, short> mood in _defaultMoods)
+            {
+                if (!Moods.ContainsKey(mood.Key))
+                {
+                    throw new InvalidOperationException("Attempting to assign default mood levels to non-default moods.");
+                }
+            }
+
+            Moods = _defaultMoods.ToDictionary(x => x.Key, x => (short?)x.Value);
+        }
+
         /// <summary>
         /// Moods can be customized and can be any string. This will keep track of all unique moods.
         /// </summary>
-        /// <remarks>Unfortunately there is no way to assign a scale to the moods from the CSV data. This could potentially eventually be done through a manual assignment extension. </remarks>
         private void InitializeMoods()
         {
             if (_CSVData == null)
@@ -44,12 +82,9 @@ private void InitializeMoods()
                 return;
             }
 
-            foreach (string? mood in _CSVData.Select(x => x.Mood).Distinct())
+            foreach (string mood in _CSVData.Select(x => x.Mood).Distinct())
             {
-                if (mood != null)
-                {
-                    Moods.Add(mood);
-                }
+                Moods.Add(mood, null);
             }
         }