These temperature readings are taken using an Arduino Ethernet module and is installed in the summerhouse at home.
Using a pair of One Wire Digital Temperature Sensors - DS18B20, the data below shows the temperatures in North Devon, England.
The unit has been running very reliably since 2012, except for the odd power cut.
Although this is a small unit, it is surprisingly accurate and provides remote temperature sensing for very little cost.

Temperature readings are temporarily offline as Storm Dennis blew the Summerhouse down