Sensor to turn lights on based on lighting conditions

Hello,

I am looking for a way to turn a group of lights (or room) based on if it gets dark outside. Basically, when its dark out during the day during a storm, etc… turn certain lights on automatically.

Any recommendations?

Thanks in advance!

I am using this method to open/close my curtains in stages and I use a photosensitive sensor to control some parts of my lightings which are more accurate and in real time.

Cool… thanks! I will look into sensor. Anyone using Insteon motions sensors to do the same?