diff --git a/homeassistant/components/tado/sensor.py b/homeassistant/components/tado/sensor.py
index 68b470aced7..a928b61a508 100644
--- a/homeassistant/components/tado/sensor.py
+++ b/homeassistant/components/tado/sensor.py
@@ -21,6 +21,7 @@ ZONE_SENSORS = {
         "tado mode",
         "overlay",
         "early start",
+        "open window",
     ],
     TYPE_AIR_CONDITIONING: [
         "temperature",
@@ -240,3 +241,9 @@ class TadoSensor(Entity):
                 self._state = True
             else:
                 self._state = False
+
+        elif self.zone_variable == "open window":
+            if "openWindowDetected" in data:
+                self._state = data["openWindowDetected"]
+            else:
+                self._state = False