diff --git a/PkmnLib.Dynamic/Models/BattleFlow/TurnRunner.cs b/PkmnLib.Dynamic/Models/BattleFlow/TurnRunner.cs
index acb1957..8195e99 100644
--- a/PkmnLib.Dynamic/Models/BattleFlow/TurnRunner.cs
+++ b/PkmnLib.Dynamic/Models/BattleFlow/TurnRunner.cs
@@ -57,15 +57,15 @@ public static class TurnRunner
                 {
                     scripts.Clear();
                     pokemon.GetOwnScripts(scripts);
-                    scripts.RunScriptHook(x => x.OnEndTurn());
+                    scripts.RunScriptHook(x => x.OnEndTurn(battle));
                 }
                 scripts.Clear();
                 side.GetOwnScripts(scripts);
-                scripts.RunScriptHook(x => x.OnEndTurn());
+                scripts.RunScriptHook(x => x.OnEndTurn(battle));
             }
             scripts.Clear();
             battle.GetOwnScripts(scripts);
-            scripts.RunScriptHook(x => x.OnEndTurn());
+            scripts.RunScriptHook(x => x.OnEndTurn(battle));
         }
     }
 
diff --git a/PkmnLib.Dynamic/Models/DamageSource.cs b/PkmnLib.Dynamic/Models/DamageSource.cs
index 33a6d2f..9b1242f 100644
--- a/PkmnLib.Dynamic/Models/DamageSource.cs
+++ b/PkmnLib.Dynamic/Models/DamageSource.cs
@@ -25,4 +25,9 @@ public enum DamageSource
     /// This happens when the form of a Pokemon changes, and it has less max HP than it had before.
     /// </summary>
     FormChange = 3,
+    
+    /// <summary>
+    /// The damage is done because of the weather.
+    /// </summary>
+    Weather = 4,
 }
\ No newline at end of file
diff --git a/PkmnLib.Dynamic/ScriptHandling/Script.cs b/PkmnLib.Dynamic/ScriptHandling/Script.cs
index 71abbee..0b01cd8 100644
--- a/PkmnLib.Dynamic/ScriptHandling/Script.cs
+++ b/PkmnLib.Dynamic/ScriptHandling/Script.cs
@@ -428,7 +428,8 @@ public abstract class Script : IDeepCloneable
     /// running. Note that choices are not active anymore here, so their scripts do not call this
     /// function.
     /// </summary>
-    public virtual void OnEndTurn()
+    /// <param name="battle"></param>
+    public virtual void OnEndTurn(IBattle battle)
     {
     }
 
diff --git a/Plugins/PkmnLib.Plugin.Gen7/Scripts/Pokemon/HealEachEndOfTurnEffect.cs b/Plugins/PkmnLib.Plugin.Gen7/Scripts/Pokemon/HealEachEndOfTurnEffect.cs
index 191c7eb..6c1f379 100644
--- a/Plugins/PkmnLib.Plugin.Gen7/Scripts/Pokemon/HealEachEndOfTurnEffect.cs
+++ b/Plugins/PkmnLib.Plugin.Gen7/Scripts/Pokemon/HealEachEndOfTurnEffect.cs
@@ -20,8 +20,9 @@ public class HealEachEndOfTurnEffect : Script
         _pokemon = pokemon;
     }
 
+    /// <param name="battle"></param>
     /// <inheritdoc />
-    public override void OnEndTurn()
+    public override void OnEndTurn(IBattle battle)
     {
         if (_pokemon is null)
             return;
diff --git a/Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/AuroraVeilEffect.cs b/Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/AuroraVeilEffect.cs
index a5bfaac..7e1f2f7 100644
--- a/Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/AuroraVeilEffect.cs
+++ b/Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/AuroraVeilEffect.cs
@@ -35,8 +35,9 @@ public class AuroraVeilEffect : Script
         NumberOfTurns = numberOfTurns;
     }
 
+    /// <param name="battle"></param>
     /// <inheritdoc />
-    public override void OnEndTurn()
+    public override void OnEndTurn(IBattle battle)
     {
         if (NumberOfTurns > 0)
             NumberOfTurns--;
diff --git a/Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/DoublePowerIfTargetDamagedInTurnData.cs b/Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/DoublePowerIfTargetDamagedInTurnData.cs
index 2ca195b..302c2d7 100644
--- a/Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/DoublePowerIfTargetDamagedInTurnData.cs
+++ b/Plugins/PkmnLib.Plugin.Gen7/Scripts/Side/DoublePowerIfTargetDamagedInTurnData.cs
@@ -9,9 +9,10 @@ namespace PkmnLib.Plugin.Gen7.Scripts.Side;
 public class DoublePowerIfTargetDamagedInTurnData : Script
 {
     public HashSet<IPokemon> _hitPokemon = new();
-    
+
+    /// <param name="battle"></param>
     /// <inheritdoc />
-    public override void OnEndTurn()
+    public override void OnEndTurn(IBattle battle)
     {
         RemoveSelf();
     }
diff --git a/Plugins/PkmnLib.Plugin.Gen7/Scripts/Weather/Hail.cs b/Plugins/PkmnLib.Plugin.Gen7/Scripts/Weather/Hail.cs
index ed14160..277be46 100644
--- a/Plugins/PkmnLib.Plugin.Gen7/Scripts/Weather/Hail.cs
+++ b/Plugins/PkmnLib.Plugin.Gen7/Scripts/Weather/Hail.cs
@@ -1,10 +1,53 @@
+using System.Collections.Generic;
+using System.Linq;
+using PkmnLib.Dynamic.Events;
+using PkmnLib.Dynamic.Models;
 using PkmnLib.Dynamic.ScriptHandling;
 using PkmnLib.Dynamic.ScriptHandling.Registry;
+using PkmnLib.Static;
+using PkmnLib.Static.Utils;
 
 namespace PkmnLib.Plugin.Gen7.Scripts.Weather;
 
 [Script(ScriptCategory.Weather, "hail")]
 public class Hail : Script
 {
-    // TODO: Implement Hail weather effect
+    public static void RegisterHailIgnoreAbility(StringKey abilityName)
+    {
+        _hailIgnoreAbilities.Add(abilityName);
+    }
+
+    private static readonly HashSet<StringKey> _hailIgnoreAbilities =
+    [
+        "ice_body",
+        "magic_guard",
+        "overcoat",
+        "snow_cloak"
+    ];
+
+    /// <inheritdoc />
+    public override void OnEndTurn(IBattle battle)
+    {
+        if (!battle.Library.StaticLibrary.Types.TryGetTypeIdentifier("ice", out var iceType))
+        {
+            iceType = new TypeIdentifier(255);
+        }
+        foreach (var side in battle.Sides)
+        {
+            foreach (var pokemon in side.Pokemon.WhereNotNull())
+            {
+                if (!pokemon.IsUsable)
+                    continue;
+                if (pokemon.Types.Contains(iceType))
+                    continue;
+                if (_hailIgnoreAbilities.Contains(pokemon.ActiveAbility.Name))
+                    continue;
+
+                var maxHealth = pokemon.BoostedStats.Hp;
+                var damage = maxHealth / 16;
+                // TODO: Consider Safety Goggles. Handle it inside the Damage method?
+                pokemon.Damage(damage, DamageSource.Weather, new EventBatchId());
+            }
+        }
+    }
 }
\ No newline at end of file