Not for SoCal mountains
I have used this app for a few weeks now. The only things Dark Sky gets correct is my physical location at 6800 feet in the San Bernardino Mountains and the current temperature. Forecasts seem to be for some other distant location consistent with an elevation of about 3000 feet with high and low temperatures completely inaccurate for my locale. Radar is vague compared real-time to all of my other weather radar apps and fails to notify of precipitation correctly. I have also received false precipitation notifications when all of my other weather apps and the National Weather Service were correctly showing no precipitation. I would not solely rely on this app for outdoor mountain activities where it is important to know if or when the weather will turn hazardous. From the reviews Ive read, this app seems to work best for cities in the flatlands.
Fogenbaugh about
Dark Sky Weather