diff --git a/homeassistant/components/tado/sensor.py b/homeassistant/components/tado/sensor.py
index 87d2170eb75..e1219b5620b 100644
--- a/homeassistant/components/tado/sensor.py
+++ b/homeassistant/components/tado/sensor.py
@@ -139,7 +139,7 @@ class TadoHomeSensor(TadoHomeEntity, SensorEntity):
     @property
     def unit_of_measurement(self):
         """Return the unit of measurement."""
-        if self.home_variable == "temperature":
+        if self.home_variable in ["temperature", "outdoor temperature"]:
             return TEMP_CELSIUS
         if self.home_variable == "solar percentage":
             return PERCENTAGE