diff --git a/js/koi/gui/menu/menu.js b/js/koi/gui/menu/menu.js
index da712591..71992f48 100644
--- a/js/koi/gui/menu/menu.js
+++ b/js/koi/gui/menu/menu.js
@@ -4,6 +4,7 @@
  * @param {LoaderFullscreen} fullscreen The fullscreen object
  * @param {String} locale The locale string
  * @param {AudioEngine} audioEngine The audio engine
+ * @param {Object} externalSettings The external settings object
  * @param {AudioBank} audio Game audio
  * @constructor
  */
@@ -12,10 +13,11 @@ const Menu = function(
     fullscreen,
     locale,
     audioEngine,
+    externalSettings,
     audio) {
     this.buttonBack = this.createButtonExit(audio);
     this.languageChooser = this.createLanguageChooser(locale);
-    this.box = this.createBox(fullscreen, audioEngine, audio);
+    this.box = this.createBox(fullscreen, audioEngine, externalSettings, audio);
     this.element = element;
     this.element.onclick = this.hide.bind(this);
     this.element.appendChild(this.box);
@@ -26,6 +28,7 @@ Menu.prototype.CLASS_VISIBLE = "visible";
 Menu.prototype.LANG_TITLE = "MENU";
 Menu.prototype.LANG_VOLUME = "VOLUME";
 Menu.prototype.LANG_GRASS_AUDIO = "TOGGLE_GRASS_AUDIO";
+Menu.prototype.LANG_FLASHES = "TOGGLE_FLASHES";
 Menu.prototype.LANG_FULLSCREEN = "TOGGLE_FULLSCREEN";
 Menu.prototype.LANG_MENU = "MENU";
 Menu.prototype.LANG_LANGUAGE = "LANGUAGE";
@@ -34,6 +37,7 @@ Menu.prototype.LANG_EXIT = "BACK";
 Menu.prototype.KEY_VOLUME = "volume";
 Menu.prototype.KEY_LANGUAGE = "language";
 Menu.prototype.KEY_GRASS_AUDIO = "grass-audio";
+Menu.prototype.KEY_FLASHES = "flashes";
 Menu.prototype.LANGUAGES = [
     ["en", "English"],
     ["de", "Deutsch (German)"],
@@ -55,10 +59,15 @@ Menu.prototype.LANGUAGES = [
  * Create the menu box
  * @param {LoaderFullscreen} fullscreen The fullscreen object
  * @param {AudioEngine} audioEngine The audio engine
+ * @param {Object} externalSettings The external settings object
  * @param {AudioBank} audio Game audio
  * @returns {HTMLDivElement} The menu box
  */
-Menu.prototype.createBox = function(fullscreen, audioEngine, audio) {
+Menu.prototype.createBox = function(
+    fullscreen,
+    audioEngine,
+    externalSettings,
+    audio) {
     const element = document.createElement("div");
     const table = document.createElement("table");
 
@@ -69,6 +78,7 @@ Menu.prototype.createBox = function(fullscreen, audioEngine, audio) {
 
     table.appendChild(this.createVolumeSlider(audioEngine));
     table.appendChild(this.createGrassAudioToggle(audioEngine));
+    table.appendChild(this.createFlashToggle(externalSettings));
     table.appendChild(this.languageChooser);
 
     element.appendChild(table);
@@ -193,6 +203,42 @@ Menu.prototype.createGrassAudioToggle = function(audioEngine) {
     return row;
 };
 
+/**
+ * Create the thunderstorm flash toggle
+ * @param {Object} externalSettings The external settings object
+ * @returns {HTMLTableRowElement} The effect toggle
+ */
+Menu.prototype.createFlashToggle = function(externalSettings) {
+    const row = document.createElement("tr");
+    const label = document.createElement("label");
+    const element = document.createElement("input");
+
+    element.type = "checkbox";
+    element.checked = true;
+
+    if (window["localStorage"].getItem(this.KEY_FLASHES)) {
+        element.checked = window["localStorage"].getItem(this.KEY_FLASHES) === "true";
+
+        externalSettings.flash = element.checked;
+    }
+    else
+        element.checked = true;
+
+    element.onchange = () => {
+        window["localStorage"].setItem(this.KEY_FLASHES, element.checked.toString());
+
+        externalSettings.flash = element.checked;
+    };
+
+    label.appendChild(document.createTextNode(language.get(this.LANG_FLASHES)));
+    label.appendChild(element);
+
+    row.appendChild(this.createTD(label));
+    row.appendChild(this.createTD(element));
+
+    return row;
+}
+
 /**
  * Create a language chooser
  * @param {String} locale The locale string
diff --git a/js/koi/koi.js b/js/koi/koi.js
index 981cc5da..98243ad6 100644
--- a/js/koi/koi.js
+++ b/js/koi/koi.js
@@ -475,8 +475,9 @@ Koi.prototype.update = function() {
 /**
  * Render the scene
  * @param {Number} deltaTime The amount of time passed since the last frame
+ * @param {Object} externalSettings The external settings object
  */
-Koi.prototype.render = function(deltaTime) {
+Koi.prototype.render = function(deltaTime, externalSettings) {
     this.time += Math.min(this.FRAME_TIME_MAX, deltaTime);
 
     while (this.time > this.UPDATE_RATE) {
@@ -562,7 +563,8 @@ Koi.prototype.render = function(deltaTime) {
     // Render weather effects
     this.weatherFilterChanged = this.weather.render(
         this.systems.drops,
-        time);
+        time,
+        externalSettings.flash);
 
     // Disable Z buffer
     this.systems.gl.disable(this.systems.gl.DEPTH_TEST);
diff --git a/js/koi/weather/weather.js b/js/koi/weather/weather.js
index 68cd1765..76c6fe84 100644
--- a/js/koi/weather/weather.js
+++ b/js/koi/weather/weather.js
@@ -247,9 +247,10 @@ Weather.prototype.interpolateFilter = function(transition) {
  * Render weather effects
  * @param {Drops} drops The drops renderer
  * @param {Number} time The interpolation factor
+ * @param {boolean} flashes True if flashes should render
  * @returns {Boolean} True if the filter color has changed
  */
-Weather.prototype.render = function(drops, time) {
+Weather.prototype.render = function(drops, time, flashes) {
     const transition = this.transitionPrevious + (this.transition - this.transitionPrevious) * time;
 
     this.gl.enable(this.gl.BLEND);
@@ -274,7 +275,7 @@ Weather.prototype.render = function(drops, time) {
 
     this.gl.disable(this.gl.BLEND);
 
-    if (this.lightning !== 0 && this.state.state === this.state.ID_THUNDERSTORM) {
+    if (flashes && this.lightning !== 0 && this.state.state === this.state.ID_THUNDERSTORM) {
         const lighting = this.lightningPrevious + (this.lightning - this.lightningPrevious) * time;
         const power = this.SAMPLER_LIGHTING.sample(lighting);
 
diff --git a/js/main.js b/js/main.js
index 59094205..57436eac 100644
--- a/js/main.js
+++ b/js/main.js
@@ -104,6 +104,10 @@ if (gl &&
     language.load(() => {
         imperial = language.get("UNIT_LENGTH") === "ft";
 
+        const settings = {
+            flash: true
+        };
+
         let session = new Session();
         let slot = null;
         const slotNames = ["session", "session2", "session3"];
@@ -119,6 +123,7 @@ if (gl &&
             loader.fullscreen,
             chosenLocale,
             audioEngine,
+            settings,
             audio);
         let lastTime = null;
         let koi = null;
@@ -203,7 +208,7 @@ if (gl &&
 
         const loop = time => {
             if (loaded) {
-                koi.render(.001 * (time - lastTime));
+                koi.render(.001 * (time - lastTime), settings);
 
                 lastTime = time;