Electronic – ‘best’ temperature sensor for an array of sensors

I'm looking to make an array of sensors to record the temperatures in a house at various points

eg. Above flat metal roof,
inside flat roof cavity (above 1st floor),
ceiling of room (1st floor),
floor of room (1st floor),
floor cavity (first floor),
ground floor room ceiling,
sub-floor/basement space.

I guess I need accuracy tolerance of about ± 1ºC. More important is that once initially calibrated, the sensor do not drift relative to temperature or the data comparison will be bunk. I hope to run the sensors for weeks in winter, summer, spring, autumn to get a full profile of the thermal performance.

So which sensors are good for me. Few seem to be good for ± 1ºC and I need a way to deal with the wiring of them too. So I2C or another digital bus might be good, anything that stops the length of the wire introducing errors into the values. Digital also means I can run a cat5 daisy chain of sensors rather than a separate lead to each sensor which seems reasonable.