diff --git a/homeassistant/components/sensor/darksky.py b/homeassistant/components/sensor/darksky.py
index c57b4ba30e8..173990a6a2f 100644
--- a/homeassistant/components/sensor/darksky.py
+++ b/homeassistant/components/sensor/darksky.py
@@ -104,19 +104,17 @@ def setup_platform(hass, config, add_devices, discovery_info=None):
     else:
         units = 'us'
 
-    # Create a data fetcher to support all of the configured sensors. Then make
-    # the first call to init the data and confirm we can connect.
-    try:
-        forecast_data = DarkSkyData(
-            api_key=config.get(CONF_API_KEY, None),
-            latitude=hass.config.latitude,
-            longitude=hass.config.longitude,
-            units=units,
-            interval=config.get(CONF_UPDATE_INTERVAL))
-        forecast_data.update()
-        forecast_data.update_currently()
-    except ValueError as error:
-        _LOGGER.error(error)
+    forecast_data = DarkSkyData(
+        api_key=config.get(CONF_API_KEY, None),
+        latitude=hass.config.latitude,
+        longitude=hass.config.longitude,
+        units=units,
+        interval=config.get(CONF_UPDATE_INTERVAL))
+    forecast_data.update()
+    forecast_data.update_currently()
+
+    # If connection failed don't setup platform.
+    if forecast_data.data is None:
         return False
 
     name = config.get(CONF_NAME)
@@ -227,7 +225,10 @@ class DarkSkySensor(Entity):
         If the sensor type is unknown, the current state is returned.
         """
         lookup_type = convert_to_camel(self.type)
-        state = getattr(data, lookup_type, 0)
+        state = getattr(data, lookup_type, None)
+
+        if state is None:
+            return state
 
         # Some state data needs to be rounded to whole values or converted to
         # percentages
@@ -284,21 +285,22 @@ class DarkSkyData(object):
             self.data = forecastio.load_forecast(
                 self._api_key, self.latitude, self.longitude, units=self.units)
         except (ConnectError, HTTPError, Timeout, ValueError) as error:
-            raise ValueError("Unable to init Dark Sky. %s", error)
-        self.unit_system = self.data.json['flags']['units']
+            _LOGGER.error("Unable to connect to Dark Sky. %s", error)
+            self.data = None
+        self.unit_system = self.data and self.data.json['flags']['units']
 
     def _update_currently(self):
         """Update currently data."""
-        self.data_currently = self.data.currently()
+        self.data_currently = self.data and self.data.currently()
 
     def _update_minutely(self):
         """Update minutely data."""
-        self.data_minutely = self.data.minutely()
+        self.data_minutely = self.data and self.data.minutely()
 
     def _update_hourly(self):
         """Update hourly data."""
-        self.data_hourly = self.data.hourly()
+        self.data_hourly = self.data and self.data.hourly()
 
     def _update_daily(self):
         """Update daily data."""
-        self.data_daily = self.data.daily()
+        self.data_daily = self.data and self.data.daily()
diff --git a/tests/components/sensor/test_darksky.py b/tests/components/sensor/test_darksky.py
index 09ced049b58..976a9278452 100644
--- a/tests/components/sensor/test_darksky.py
+++ b/tests/components/sensor/test_darksky.py
@@ -17,6 +17,15 @@ from tests.common import load_fixture, get_test_home_assistant
 class TestDarkSkySetup(unittest.TestCase):
     """Test the Dark Sky platform."""
 
+    def add_entities(self, new_entities, update_before_add=False):
+        """Mock add entities."""
+        if update_before_add:
+            for entity in new_entities:
+                entity.update()
+
+        for entity in new_entities:
+            self.entities.append(entity)
+
     def setUp(self):
         """Initialize values for this testcase class."""
         self.hass = get_test_home_assistant()
@@ -30,6 +39,7 @@ class TestDarkSkySetup(unittest.TestCase):
         self.lon = -122.423
         self.hass.config.latitude = self.lat
         self.hass.config.longitude = self.lon
+        self.entities = []
 
     def test_setup_with_config(self):
         """Test the platform setup with configuration."""
@@ -63,6 +73,7 @@ class TestDarkSkySetup(unittest.TestCase):
                r'(-?\d+\.?\d*),(-?\d+\.?\d*)')
         mock_req.get(re.compile(uri),
                      text=load_fixture('darksky.json'))
-        darksky.setup_platform(self.hass, self.config, MagicMock())
+        darksky.setup_platform(self.hass, self.config, self.add_entities)
         self.assertTrue(mock_get_forecast.called)
         self.assertEqual(mock_get_forecast.call_count, 1)
+        self.assertEqual(len(self.entities), 2)