Microchip has released a temperature sensor accurate to +/-1°C from -40 to +125°C. Called MCP9804, the device is typically +0.25°C accurate and consumes 200µA.
Shutdown is programmable to extend battery life, and there is over and under temperature alert for window monitoring, as well as a critical over temperature-alert alert.
The interface is I2C and there are two package options: 8pin MSOP or 2x3mm DFN.
Example applications include industrial freezers, personal computers and engine temperature monitoring.