Please note, iSocket can only be used indoors, however ways can be found to get around this. In most cases an outdoor appliance is powered from an indoor electric supply and in some cases you may even have an indoor outlet connected to the same network. If you only need to detect a power failure and do not need to switch your outdoor equipment remotely, then you could plug the iSocket to the indoor outlet. Since the electric network is the same and connected in parallel, when the power fails it will fail on this indoor outlet as well. iSocket will detect this and you will get a power failure notification. You may consult with a local electrician about how your system is wired and he could probably help you with the installation. If your outdoor equipment has a plug that can be routed from inside the premises then you may consider doing that and move the iSocket indoors.
Another option is to use special insulated boxes which allow indoor equipment to be used outside, but please note that temperature and humidity conditions must be kept in mind - to merely protect against rain/snow is not enough.
Read useful article about using electronics in a cold environment.