diff --git a/WeatherPredictor/web_page.h b/WeatherPredictor/web_page.h
index e306cdf..3a6b8e7 100644
--- a/WeatherPredictor/web_page.h
+++ b/WeatherPredictor/web_page.h
@@ -39,6 +39,11 @@ static const char INDEX_HTML[] PROGMEM = R"HTML(
   }
   .lede{color:var(--muted); font-size:.92rem; margin:8px 0 0}
   .lede b{color:var(--text); font-weight:600}
+  header{position:relative}
+  .lang{position:absolute; top:0; right:0; display:flex; gap:3px}
+  .lang button{padding:4px 9px; font-size:.72rem; font-weight:700; letter-spacing:.06em; font-family:var(--sans);
+    background:transparent; color:var(--muted); border:1px solid var(--line); border-radius:7px; cursor:pointer}
+  .lang button.on{background:var(--brass); color:#221a06; border-color:var(--brass)}
 
   .panel{
     background:linear-gradient(180deg, var(--surface), #14203a);
@@ -153,9 +158,10 @@ static const char INDEX_HTML[] PROGMEM = R"HTML(
 <div class="wrap">
 
   <header>
-    <p class="eyebrow">Barometric Forecaster</p>
-    <h1>Weather&nbsp;Predictor</h1>
-    <p class="lede">Reading the sky by pressure alone, the <b>Zambretti</b> way — station at
+    <div class="lang" id="lang"><button type="button" data-lang="ru">RU</button><button type="button" data-lang="en">EN</button></div>
+    <p class="eyebrow" data-i18n="eyebrow">Barometric Forecaster</p>
+    <h1 data-i18n="title">Weather Predictor</h1>
+    <p class="lede"><span data-i18n="lede">Reading the sky by pressure alone, the Zambretti way — station at</span>
       <span id="coords">54.99&deg;N, 82.87&deg;E</span>.</p>
   </header>
 
@@ -164,7 +170,7 @@ static const char INDEX_HTML[] PROGMEM = R"HTML(
     <svg id="gauge" viewBox="0 0 400 232" role="img" aria-label="Barometer dial"></svg>
     <div class="readout">
       <span class="pressure"><span id="msl">----</span></span>
-      <span class="unit">hPa&nbsp;·&nbsp;sea level</span>
+      <span class="unit" data-i18n="unit_msl">hPa&nbsp;·&nbsp;sea level</span>
       <span class="chip" id="chip" style="color:var(--muted)">&mdash;</span>
     </div>
     <p class="verdict" id="verdict">Reading the sky&hellip;</p>
@@ -173,18 +179,18 @@ static const char INDEX_HTML[] PROGMEM = R"HTML(
 
   <!-- Stats -->
   <section class="panel stats">
-    <div class="stat"><div class="k">Local time</div><div class="v" id="time">--:--</div><div class="s" id="date">&mdash;</div></div>
-    <div class="stat"><div class="k">Temperature</div><div class="v" id="temp">--</div><div class="s">degrees celsius</div></div>
-    <div class="stat"><div class="k">3-hour move</div><div class="v" id="delta">&mdash;</div><div class="s" id="deltas">&mdash;</div></div>
+    <div class="stat"><div class="k" data-i18n="k_time">Local time</div><div class="v" id="time">--:--</div><div class="s" id="date">&mdash;</div></div>
+    <div class="stat"><div class="k" data-i18n="k_temp">Temperature</div><div class="v" id="temp">--</div><div class="s" data-i18n="s_celsius">degrees celsius</div></div>
+    <div class="stat"><div class="k" data-i18n="k_move">3-hour move</div><div class="v" id="delta">&mdash;</div><div class="s" id="deltas">&mdash;</div></div>
   </section>
 
   <!-- Barograph -->
   <section class="panel panel-pad">
     <div class="head">
-      <h2>Barograph</h2>
+      <h2 data-i18n="barograph">Barograph</h2>
       <div class="legend">
-        <span><i style="background:var(--change)"></i>Pressure</span>
-        <span><i style="background:var(--fair)"></i>Temperature</span>
+        <span><i style="background:var(--change)"></i><span data-i18n="pressure">Pressure</span></span>
+        <span><i style="background:var(--fair)"></i><span data-i18n="temperature">Temperature</span></span>
       </div>
     </div>
     <div class="baro">
@@ -199,7 +205,7 @@ static const char INDEX_HTML[] PROGMEM = R"HTML(
   <!-- Forecast log -->
   <section class="panel panel-pad">
     <div class="head">
-      <h2>Forecast log</h2>
+      <h2 data-i18n="flog">Forecast log</h2>
       <span class="cap" id="log-cap"></span>
     </div>
     <ol class="log" id="log"></ol>
@@ -207,27 +213,27 @@ static const char INDEX_HTML[] PROGMEM = R"HTML(
 
   <!-- Settings -->
   <details class="panel set">
-    <summary>Station settings <span class="caret">Adjust</span></summary>
+    <summary><span data-i18n="settings">Station settings</span> <span class="caret" data-i18n="adjust">Adjust</span></summary>
     <hr class="rule">
     <div class="form">
       <div style="margin-top:18px">
-        <label>City preset</label>
+        <label data-i18n="l_city">City preset</label>
         <select id="s-city"></select>
       </div>
       <div class="grid2" style="margin-top:14px">
-        <div><label>Altitude &middot; metres</label><input id="s-alt" type="number" step="1"></div>
-        <div><label>Time zone</label><select id="s-tz"></select></div>
-        <div><label>Latitude</label><input id="s-lat" type="number" step="0.0001"></div>
-        <div><label>Longitude</label><input id="s-lon" type="number" step="0.0001"></div>
+        <div><label data-i18n="l_alt">Altitude &middot; metres</label><input id="s-alt" type="number" step="1"></div>
+        <div><label data-i18n="l_tz">Time zone</label><select id="s-tz"></select></div>
+        <div><label data-i18n="l_lat">Latitude</label><input id="s-lat" type="number" step="0.0001"></div>
+        <div><label data-i18n="l_lon">Longitude</label><input id="s-lon" type="number" step="0.0001"></div>
       </div>
       <div class="actions">
-        <button id="save">Save settings</button>
+        <button id="save" data-i18n="save">Save settings</button>
         <span class="saved" id="saved"></span>
       </div>
     </div>
   </details>
 
-  <footer>Served from the station &middot; works without internet</footer>
+  <footer data-i18n="footer">Served from the station &middot; works without internet</footer>
 </div>
 
 <script>
@@ -242,6 +248,93 @@ var ZONES=[
 ];
 var CATCOLOR={Fine:"#8FBE8A",Fair:"#E4B658",Changeable:"#79C2D0",Rain:"#5C86D6",Storm:"#E4573B"};
 
+// ---------- i18n ----------
+var LANG=(function(){ try{ return localStorage.getItem("wp_lang")||"ru"; }catch(e){ return "ru"; } })();
+var STR={
+  ru:{
+    eyebrow:"Барометрический предсказатель", title:"Предсказатель погоды",
+    lede:"Читаем небо по одному давлению — метод Zambretti. Станция:",
+    unit_msl:"гПа · у моря",
+    k_time:"Местное время", k_temp:"Температура", k_move:"Изм. за 3 ч", s_celsius:"градусы Цельсия",
+    barograph:"Барограф", pressure:"Давление", temperature:"Температура", flog:"Журнал прогнозов",
+    settings:"Настройки станции", adjust:"Изменить",
+    l_city:"Пресет города", l_alt:"Высота · метры", l_tz:"Часовой пояс", l_lat:"Широта", l_lon:"Долгота",
+    custom:"Вручную", save:"Сохранить", footer:"Отдаётся станцией · работает без интернета",
+    warm:"Читаем небо…", warm_chip:"прогрев",
+    warm_sub:"Прогнозу нужно около трёх часов истории давления до первого вывода.",
+    verdict_pre:"Показание Zambretti — ", verdict_post:" за последние три часа.",
+    tr_rising:"давление растёт", tr_falling:"давление падает", tr_steady:"давление стабильно",
+    collecting:"Сбор данных…",
+    hint:function(n,h){return n+" измерений за "+h+" ч · давление в гПа, температура в °C";},
+    log_empty:"Пока прогнозов нет — первый появится примерно через три часа.",
+    log_cap:function(n){var d1=n%10,d2=n%100; return n+((d1===1&&d2!==11)?" смена":((d1>=2&&d1<=4&&(d2<10||d2>=20))?" смены":" смен"));},
+    need3:"нужно 3 ч данных", mv_unit:"гПа · ", mv_rising:"рост", mv_steady:"стабильно", mv_falling:"падение",
+    saved_ok:"Сохранено.", saved_err:"Не удалось сохранить.", saved_net:"Станция недоступна."
+  },
+  en:{
+    eyebrow:"Barometric Forecaster", title:"Weather Predictor",
+    lede:"Reading the sky by pressure alone, the Zambretti way — station at",
+    unit_msl:"hPa · sea level",
+    k_time:"Local time", k_temp:"Temperature", k_move:"3-hour move", s_celsius:"degrees celsius",
+    barograph:"Barograph", pressure:"Pressure", temperature:"Temperature", flog:"Forecast log",
+    settings:"Station settings", adjust:"Adjust",
+    l_city:"City preset", l_alt:"Altitude · metres", l_tz:"Time zone", l_lat:"Latitude", l_lon:"Longitude",
+    custom:"Custom / manual entry", save:"Save settings", footer:"Served from the station · works without internet",
+    warm:"Reading the sky…", warm_chip:"warming up",
+    warm_sub:"The forecaster needs about three hours of pressure history before its first call.",
+    verdict_pre:"Zambretti reading — ", verdict_post:" over the last three hours.",
+    tr_rising:"pressure rising", tr_falling:"pressure falling", tr_steady:"pressure steady",
+    collecting:"Collecting data…",
+    hint:function(n,h){return n+" readings over "+h+" h · pressure in hPa, temperature in °C";},
+    log_empty:"No forecasts yet — the first call appears after about three hours.",
+    log_cap:function(n){return n+(n>1?" changes":" change");},
+    need3:"need 3 h of data", mv_unit:"hPa · ", mv_rising:"rising", mv_steady:"steady", mv_falling:"falling",
+    saved_ok:"Saved.", saved_err:"Could not save.", saved_net:"Could not reach the station."
+  }
+};
+function T(k){ var s=STR[LANG]||STR.en; return (k in s)?s[k]:(STR.en[k]!=null?STR.en[k]:k); }
+var ZONE_RU={STORMY:"БУРЯ",RAIN:"ДОЖДЬ",CHANGE:"ПЕРЕМЕННО",FAIR:"ЯСНО","VERY DRY":"СУШЬ"};
+function zoneLabel(z){ return LANG==="ru"?(ZONE_RU[z]||z):z; }
+var CATS={Fine:"Ясно",Fair:"Хорошо",Changeable:"Переменно",Rain:"Дождь",Storm:"Буря"};
+function trCat(s){ return (LANG==="ru"&&CATS[s])?CATS[s]:s; }
+var PHRASES={
+"Settled fine weather":"Устойчиво ясно",
+"Fine weather":"Ясная погода",
+"Becoming fine":"Проясняется",
+"Fine, becoming less settled":"Ясно, погода портится",
+"Fine, possibly showers":"Ясно, возможны ливни",
+"Fairly fine, improving":"Довольно ясно, улучшение",
+"Fairly fine, possibly showers early":"Довольно ясно, ранние ливни",
+"Fairly fine, showers later":"Довольно ясно, ливни позже",
+"Showery early, improving":"Ранние ливни, улучшение",
+"Changeable, improving":"Переменно, улучшение",
+"Fairly fine, showers likely":"Довольно ясно, вероятны ливни",
+"Rather unsettled, clearing later":"Неустойчиво, позже прояснение",
+"Unsettled, probably improving":"Неустойчиво, вероятно улучшение",
+"Showery, bright intervals":"Ливни, прояснения",
+"Showery, becoming unsettled":"Ливни, погода портится",
+"Changeable, some rain":"Переменно, местами дождь",
+"Unsettled, short fine intervals":"Неустойчиво, краткие прояснения",
+"Unsettled, rain later":"Неустойчиво, дождь позже",
+"Unsettled, rain at times":"Неустойчиво, временами дождь",
+"Very unsettled, finer at times":"Очень неустойчиво, временами лучше",
+"Rain at times, worse later":"Временами дождь, позже хуже",
+"Rain at times, becoming very unsettled":"Временами дождь, резко портится",
+"Rain at frequent intervals":"Частые дожди",
+"Very unsettled, rain":"Очень неустойчиво, дождь",
+"Stormy, possibly improving":"Буря, возможно улучшение",
+"Stormy, much rain":"Буря, сильный дождь"
+};
+function trPhrase(s){ return (LANG==="ru"&&PHRASES[s])?PHRASES[s]:s; }
+function applyLang(){
+  document.documentElement.lang=LANG;
+  document.querySelectorAll("[data-i18n]").forEach(function(el){ el.textContent=T(el.getAttribute("data-i18n")); });
+  ZONES.forEach(function(z){ var lab=document.getElementById("lab-"+z.label); if(lab) lab.textContent=zoneLabel(z.label); });
+  var city=document.getElementById("s-city"); if(city&&city.options.length) city.options[0].textContent=T("custom");
+  document.querySelectorAll("#lang button").forEach(function(b){ b.classList.toggle("on", b.getAttribute("data-lang")===LANG); });
+}
+function setLang(l){ LANG=l; try{localStorage.setItem("wp_lang",l);}catch(e){} applyLang(); refresh(); }
+
 function clamp(v,a,b){return v<a?a:(v>b?b:v);}
 // pressure -> screen angle (deg): 960=180 (left), 1060=0 (right)
 function angleOf(p){return 180 - (clamp(p,PMIN,PMAX)-PMIN)/(PMAX-PMIN)*180;}
@@ -329,15 +422,15 @@ async function refresh(){
     // verdict
     var v=document.getElementById("verdict"), vs=document.getElementById("verdict-sub"), chip=document.getElementById("chip");
     if(c.haveTrend){
-      v.textContent=c.forecast;
+      v.textContent=trPhrase(c.forecast);
       var col=CATCOLOR[c.category]||"#93A3BE";
-      chip.textContent=c.category; chip.style.color=col;
-      var word=c.trend>0?"pressure rising":(c.trend<0?"pressure falling":"pressure steady");
-      vs.textContent="Zambretti reading — "+word+" over the last three hours.";
+      chip.textContent=trCat(c.category); chip.style.color=col;
+      var word=c.trend>0?T("tr_rising"):(c.trend<0?T("tr_falling"):T("tr_steady"));
+      vs.textContent=T("verdict_pre")+word+T("verdict_post");
     }else{
-      v.textContent="Reading the sky…";
-      chip.textContent="warming up"; chip.style.color="#93A3BE";
-      vs.textContent="The forecaster needs about three hours of pressure history before its first call.";
+      v.textContent=T("warm");
+      chip.textContent=T("warm_chip"); chip.style.color="#93A3BE";
+      vs.textContent=T("warm_sub");
     }
     document.getElementById("chip").setAttribute("aria-label",c.category||"");
     // absolute already implied; keep footer clean
@@ -356,7 +449,7 @@ async function drawLog(){
   ol.innerHTML="";
   if(!data.length){
     var li=document.createElement("li"); li.className="empty";
-    li.textContent="No forecasts yet — the first call appears after about three hours.";
+    li.textContent=T("log_empty");
     ol.appendChild(li); cap.textContent=""; return;
   }
   data.forEach(function(e){
@@ -364,13 +457,13 @@ async function drawLog(){
     var dot=document.createElement("span"); dot.className="dot";
     dot.style.background=CATCOLOR[e.cat]||"#93A3BE"; li.appendChild(dot);
     var lt=document.createElement("div"); lt.className="lt";
-    var b=document.createElement("b"); b.textContent=e.text; lt.appendChild(b);
-    var lc=document.createElement("div"); lc.className="lc"; lc.textContent=e.cat; lt.appendChild(lc);
+    var b=document.createElement("b"); b.textContent=trPhrase(e.text); lt.appendChild(b);
+    var lc=document.createElement("div"); lc.className="lc"; lc.textContent=trCat(e.cat); lt.appendChild(lc);
     li.appendChild(lt);
     var tm=document.createElement("time"); tm.textContent=fmtStamp(e.t); li.appendChild(tm);
     ol.appendChild(li);
   });
-  cap.textContent=data.length+(data.length>1?" changes":" change");
+  cap.textContent=T("log_cap")(data.length);
 }
 function fillAxis(id,mx,mn,deg){
   var box=document.getElementById(id); box.innerHTML="";
@@ -387,7 +480,7 @@ async function drawChart(){
   var svg=document.getElementById("chart"), W=640,H=200,pad=6;
   while(svg.firstChild) svg.removeChild(svg.firstChild);
   if(!data.length){
-    document.getElementById("hint").textContent="Collecting data…";
+    document.getElementById("hint").textContent=T("collecting");
     document.getElementById("axL").innerHTML=""; document.getElementById("axR").innerHTML="";
     document.getElementById("axT0").textContent="—"; document.getElementById("axT1").textContent="—";
     updateSetHand(); return;
@@ -412,7 +505,7 @@ async function drawChart(){
   document.getElementById("axT0").textContent=fmtTime(data[0].t);
   document.getElementById("axT1").textContent=fmtTime(data[n-1].t);
   var hrs=((data[n-1].t-data[0].t)/3600);
-  document.getElementById("hint").textContent=n+" readings over "+hrs.toFixed(1)+" h · pressure in hPa, temperature in °C";
+  document.getElementById("hint").textContent=T("hint")(n, hrs.toFixed(1));
   updateSetHand();
 }
 
@@ -425,13 +518,13 @@ function updateSetHand(){
   for(var i=0;i<d.length;i++){ if(d[i].t<=target) past=d[i]; }
   if(!past || (latest.t-past.t)<9000){ sh.setAttribute("opacity",0);
     document.getElementById("delta").textContent="—";
-    document.getElementById("deltas").textContent="need 3 h of data"; return; }
+    document.getElementById("deltas").textContent=T("need3"); return; }
   setNeedle("sethand",past.msl);
   sh.setAttribute("opacity",.7);
   var diff=latest.msl-past.msl;
   document.getElementById("delta").textContent=fmtSigned(diff,1);
-  var word=diff>1.6?"rising":(diff<-1.6?"falling":"steady");
-  document.getElementById("deltas").textContent="hPa · "+word;
+  var word=diff>1.6?T("mv_rising"):(diff<-1.6?T("mv_falling"):T("mv_steady"));
+  document.getElementById("deltas").textContent=T("mv_unit")+word;
 }
 
 function tzLabel(min){var s=min<0?"-":"+";var a=Math.abs(min);var h=Math.floor(a/60);var m=a%60;return "UTC"+s+h+(m?(":"+(m<10?"0":"")+m):"");}
@@ -457,7 +550,7 @@ function setTz(min){
 }
 function buildCities(){
   var sel=document.getElementById("s-city");
-  var o0=document.createElement("option"); o0.value="-1"; o0.textContent="Custom / manual entry"; sel.appendChild(o0);
+  var o0=document.createElement("option"); o0.value="-1"; o0.textContent=T("custom"); sel.appendChild(o0);
   CITIES.forEach(function(c,i){
     var o=document.createElement("option"); o.value=i;
     o.textContent=c.n+" · "+c.alt+" m · "+tzLabel(c.tz); sel.appendChild(o);
@@ -497,16 +590,20 @@ document.getElementById("save").addEventListener("click", async function(){
   var msg=document.getElementById("saved");
   try{
     var r=await (await fetch("/api/settings",{method:"POST",body:JSON.stringify(body)})).json();
-    msg.textContent=r.ok?"Saved.":"Could not save.";
+    msg.textContent=r.ok?T("saved_ok"):T("saved_err");
     msg.style.color=r.ok?"var(--fine)":"var(--storm)";
     if(r.ok){ loadSettings(); refresh(); }
-  }catch(e){ msg.textContent="Could not reach the station."; msg.style.color="var(--storm)"; }
+  }catch(e){ msg.textContent=T("saved_net"); msg.style.color="var(--storm)"; }
   setTimeout(function(){msg.textContent="";},4000);
 });
 
+document.querySelectorAll("#lang button").forEach(function(b){
+  b.addEventListener("click",function(){ setLang(b.getAttribute("data-lang")); });
+});
 buildGauge();
 buildTz();
 buildCities();
+applyLang();
 loadSettings();
 refresh();
 setInterval(refresh,15000);