diff --git a/src/phases/weather-effect-phase.ts b/src/phases/weather-effect-phase.ts
index 71ca7f9b505..ccfc9abb64f 100644
--- a/src/phases/weather-effect-phase.ts
+++ b/src/phases/weather-effect-phase.ts
@@ -1,10 +1,11 @@
-import BattleScene from "#app/battle-scene.js";
+import BattleScene from "#app/battle-scene";
 import { applyPreWeatherEffectAbAttrs, SuppressWeatherEffectAbAttr, PreWeatherDamageAbAttr, applyAbAttrs, BlockNonDirectDamageAbAttr, applyPostWeatherLapseAbAttrs, PostWeatherLapseAbAttr } from "#app/data/ability.js";
-import { CommonAnim } from "#app/data/battle-anims.js";
-import { Weather, getWeatherDamageMessage, getWeatherLapseMessage } from "#app/data/weather.js";
-import { WeatherType } from "#app/enums/weather-type.js";
-import Pokemon, { HitResult } from "#app/field/pokemon.js";
-import * as Utils from "#app/utils.js";
+import { CommonAnim } from "#app/data/battle-anims";
+import { Weather, getWeatherDamageMessage, getWeatherLapseMessage } from "#app/data/weather";
+import { BattlerTagType } from "#app/enums/battler-tag-type.js";
+import { WeatherType } from "#app/enums/weather-type";
+import Pokemon, { HitResult } from "#app/field/pokemon";
+import * as Utils from "#app/utils";
 import { CommonAnimPhase } from "./common-anim-phase";
 
 export class WeatherEffectPhase extends CommonAnimPhase {
@@ -39,7 +40,7 @@ export class WeatherEffectPhase extends CommonAnimPhase {
           applyPreWeatherEffectAbAttrs(PreWeatherDamageAbAttr, pokemon, this.weather, cancelled);
           applyAbAttrs(BlockNonDirectDamageAbAttr, pokemon, cancelled);
 
-          if (cancelled.value) {
+          if (cancelled.value || pokemon.getTag(BattlerTagType.UNDERGROUND) || pokemon.getTag(BattlerTagType.UNDERWATER)) {
             return;
           }
 
diff --git a/src/test/arena/weather_hail.test.ts b/src/test/arena/weather_hail.test.ts
new file mode 100644
index 00000000000..75125b3448c
--- /dev/null
+++ b/src/test/arena/weather_hail.test.ts
@@ -0,0 +1,62 @@
+import { WeatherType } from "#app/data/weather";
+import { Moves } from "#enums/moves";
+import { Species } from "#enums/species";
+import GameManager from "#test/utils/gameManager";
+import Phaser from "phaser";
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from "vitest";
+import { SPLASH_ONLY } from "../utils/testUtils";
+import { BattlerIndex } from "#app/battle";
+
+describe("Weather - Hail", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    game.override
+      .weather(WeatherType.HAIL)
+      .battleType("single")
+      .moveset(SPLASH_ONLY)
+      .enemyMoveset(SPLASH_ONLY)
+      .enemySpecies(Species.MAGIKARP);
+  });
+
+  it("inflicts damage equal to 1/16 of Pokemon's max HP at turn end", async () => {
+    await game.classicMode.startBattle([Species.MAGIKARP]);
+
+    game.move.select(Moves.SPLASH);
+    await game.setTurnOrder([BattlerIndex.ENEMY, BattlerIndex.PLAYER]);
+
+    await game.phaseInterceptor.to("TurnEndPhase");
+
+    game.scene.getField(true).forEach(pokemon => {
+      expect(pokemon.hp).toBeLessThan(pokemon.getMaxHp() - Math.floor(pokemon.getMaxHp() / 16));
+    });
+  });
+
+  it("does not inflict damage to a Pokemon that is underwater (Dive) or underground (Dig)", async () => {
+    game.override.moveset([Moves.DIG]);
+    await game.classicMode.startBattle([Species.MAGIKARP]);
+
+    game.move.select(Moves.DIG);
+    await game.setTurnOrder([BattlerIndex.ENEMY, BattlerIndex.PLAYER]);
+
+    await game.phaseInterceptor.to("TurnEndPhase");
+
+    const playerPokemon = game.scene.getPlayerPokemon()!;
+    const enemyPokemon = game.scene.getEnemyPokemon()!;
+
+    expect(playerPokemon.hp).toBe(playerPokemon.getMaxHp());
+    expect(enemyPokemon.hp).toBeLessThan(enemyPokemon.getMaxHp() - Math.floor(enemyPokemon.getMaxHp() / 16));
+  });
+});
diff --git a/src/test/arena/weather_sandstorm.test.ts b/src/test/arena/weather_sandstorm.test.ts
new file mode 100644
index 00000000000..978774ba4c1
--- /dev/null
+++ b/src/test/arena/weather_sandstorm.test.ts
@@ -0,0 +1,59 @@
+import { WeatherType } from "#app/data/weather";
+import { Moves } from "#enums/moves";
+import { Species } from "#enums/species";
+import GameManager from "#test/utils/gameManager";
+import Phaser from "phaser";
+import { afterEach, beforeAll, beforeEach, describe, expect, it } from "vitest";
+import { SPLASH_ONLY } from "../utils/testUtils";
+
+describe("Weather - Sandstorm", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  afterEach(() => {
+    game.phaseInterceptor.restoreOg();
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    game.override
+      .weather(WeatherType.SANDSTORM)
+      .battleType("single")
+      .moveset(SPLASH_ONLY)
+      .enemyMoveset(SPLASH_ONLY)
+      .enemySpecies(Species.MAGIKARP);
+  });
+
+  it("inflicts damage equal to 1/16 of Pokemon's max HP at turn end", async () => {
+    await game.classicMode.startBattle([Species.MAGIKARP]);
+
+    game.move.select(Moves.SPLASH);
+
+    await game.phaseInterceptor.to("TurnEndPhase");
+
+    game.scene.getField(true).forEach(pokemon => {
+      expect(pokemon.hp).toBeLessThan(pokemon.getMaxHp() - Math.floor(pokemon.getMaxHp() / 16));
+    });
+  });
+
+  it("does not inflict damage to a Pokemon that is underwater (Dive) or underground (Dig)", async () => {
+    game.override.moveset([Moves.DIVE]);
+    await game.classicMode.startBattle([Species.MAGIKARP]);
+
+    game.move.select(Moves.DIVE);
+
+    await game.phaseInterceptor.to("TurnEndPhase");
+
+    const playerPokemon = game.scene.getPlayerPokemon()!;
+    const enemyPokemon = game.scene.getEnemyPokemon()!;
+
+    expect(playerPokemon.hp).toBe(playerPokemon.getMaxHp());
+    expect(enemyPokemon.hp).toBeLessThan(enemyPokemon.getMaxHp() - Math.floor(enemyPokemon.getMaxHp() / 16));
+  });
+});