diff --git a/homeassistant/components/arwn/sensor.py b/homeassistant/components/arwn/sensor.py
index 3db1283279e..18186e8b871 100644
--- a/homeassistant/components/arwn/sensor.py
+++ b/homeassistant/components/arwn/sensor.py
@@ -30,26 +30,30 @@ def discover_sensors(topic, payload):
             unit = TEMP_FAHRENHEIT
         else:
             unit = TEMP_CELSIUS
-        return ArwnSensor(name, "temp", unit)
+        return ArwnSensor(topic, name, "temp", unit)
     if domain == "moisture":
         name = f"{parts[2]} Moisture"
-        return ArwnSensor(name, "moisture", unit, "mdi:water-percent")
+        return ArwnSensor(topic, name, "moisture", unit, "mdi:water-percent")
     if domain == "rain":
         if len(parts) >= 3 and parts[2] == "today":
             return ArwnSensor(
-                "Rain Since Midnight", "since_midnight", "in", "mdi:water"
+                topic, "Rain Since Midnight", "since_midnight", "in", "mdi:water"
             )
         return (
-            ArwnSensor("Total Rainfall", "total", unit, "mdi:water"),
-            ArwnSensor("Rainfall Rate", "rate", unit, "mdi:water"),
+            ArwnSensor(topic + "/total", "Total Rainfall", "total", unit, "mdi:water"),
+            ArwnSensor(topic + "/rate", "Rainfall Rate", "rate", unit, "mdi:water"),
         )
     if domain == "barometer":
-        return ArwnSensor("Barometer", "pressure", unit, "mdi:thermometer-lines")
+        return ArwnSensor(topic, "Barometer", "pressure", unit, "mdi:thermometer-lines")
     if domain == "wind":
         return (
-            ArwnSensor("Wind Speed", "speed", unit, "mdi:speedometer"),
-            ArwnSensor("Wind Gust", "gust", unit, "mdi:speedometer"),
-            ArwnSensor("Wind Direction", "direction", DEGREE, "mdi:compass"),
+            ArwnSensor(
+                topic + "/speed", "Wind Speed", "speed", unit, "mdi:speedometer"
+            ),
+            ArwnSensor(topic + "/gust", "Wind Gust", "gust", unit, "mdi:speedometer"),
+            ArwnSensor(
+                topic + "/dir", "Wind Direction", "direction", DEGREE, "mdi:compass"
+            ),
         )
 
 
@@ -95,11 +99,15 @@ async def async_setup_platform(hass, config, async_add_entities, discovery_info=
                 sensor.set_event(event)
                 store[sensor.name] = sensor
                 _LOGGER.debug(
-                    "Registering new sensor %(name)s => %(event)s",
+                    "Registering sensor %(name)s => %(event)s",
                     {"name": sensor.name, "event": event},
                 )
                 async_add_entities((sensor,), True)
             else:
+                _LOGGER.debug(
+                    "Recording sensor %(name)s => %(event)s",
+                    {"name": sensor.name, "event": event},
+                )
                 store[sensor.name].set_event(event)
 
     await mqtt.async_subscribe(hass, TOPIC, async_sensor_event_received, 0)
@@ -109,11 +117,13 @@ async def async_setup_platform(hass, config, async_add_entities, discovery_info=
 class ArwnSensor(Entity):
     """Representation of an ARWN sensor."""
 
-    def __init__(self, name, state_key, units, icon=None):
+    def __init__(self, topic, name, state_key, units, icon=None):
         """Initialize the sensor."""
         self.hass = None
         self.entity_id = _slug(name)
         self._name = name
+        # This mqtt topic for the sensor which is its uid
+        self._uid = topic
         self._state_key = state_key
         self.event = {}
         self._unit_of_measurement = units
@@ -135,6 +145,14 @@ class ArwnSensor(Entity):
         """Get the name of the sensor."""
         return self._name
 
+    @property
+    def unique_id(self):
+        """Return a unique ID.
+
+        This is based on the topic that comes from mqtt
+        """
+        return self._uid
+
     @property
     def state_attributes(self):
         """Return all the state attributes."""