Oregon Scientific releases in the UK the RMR802 solar-powered RC Clock with outdoor temperature. Obiously, the device can show you both indoor and outdoor temperature, with its remote thermo sensor. An ice alert is also included.
The RMR802 has built-in solar panel for absorbing and storing power during the day. It will switches over to the batteries power source at night. The solar thermometer is priced at GBP27.99 at Amazon UK.