diff --git a/homeassistant/components/ambient_station/entity.py b/homeassistant/components/ambient_station/entity.py
index a1a81d97c3f..24dfab438d8 100644
--- a/homeassistant/components/ambient_station/entity.py
+++ b/homeassistant/components/ambient_station/entity.py
@@ -49,7 +49,7 @@ class AmbientWeatherEntity(Entity):
         last_data = self._ambient.stations[self._mac_address][ATTR_LAST_DATA]
         key = self.entity_description.key
         available_key = TYPE_SOLARRADIATION if key == TYPE_SOLARRADIATION_LX else key
-        self._attr_available = last_data[available_key] is not None
+        self._attr_available = last_data.get(available_key) is not None
         self.update_from_latest_data()
         self.async_write_ha_state()