Yes. Compact Fluorescent light bulbs can be used outdoors. Or that is some of them can. Not all compact fluorescent light bulbs are made with the right technology that will allow them to function properly in cold weather. Philips makes their outdoor compact fluorescent light bulbs with Amalgam Technology which provides a stable light output down to -4 degrees F or sometimes -10 degrees F.
Why is this important? For the same reason that it sometimes takes a compact fluorescent to warm up and function in your home.....when you throw the cold temperatures in the mix they may never warm up enough to actually light up. So, when purchasing compact fluorescent light bulbs to use outdoors, it is very important to insure that they are made to take the cold temperatures.Holly Eddins