Google has begun selling the Nest Temperature Sensor for $39 over at the Google Store for those who already have a Nest thermostat, or plan to buy one. While the Nest thermostat on its own is a good investment for many reasons, not the least of which is the convenience as it can enable you to have the temperature adjust itself based on a variety of factors, when paired with the temperature sensor the whole setup becomes that much smarter and gains a little more usefulness, especially if you're aiming to save on energy and make things even more convenient.
While the temperature sensor is not a new announcement for the company it wasn't previously available to purchase and have it shipped out immediately as anyone interested in grabbing one could only place a pre-order for the device and wait for it to arrive. Now that it's officially available, anyone who did pre-order it should start seeing the device show up in the mail or on their doorstep. The sensor, which Google notes can be placed relatively anywhere in the home, acts as a way to tell the thermostat which temperature a specific room should be at based on the time of day. For instance, if you want the living room to be at about 70 degrees around 5 in the evening as you're coming home, the sensor would let the thermostat know to prioritize this room over others at that time. Google points out that different rooms in the home aren't typically all at the same temperature, which is what makes these sensors a bright idea.
Naturally things would have to be configured for this to all work and there are a couple of caveats. You have to have a third-gen Nest Learning Thermostat or the Nest Thermostat E as these are the only two models the sensor is compatible with. If you want a sensor in every room of the home it's possible to do this, but you can only have up to six working with one thermostat. If you have two or three thermostats however, you can add additional sensors where you need them, and you can have up to eighteen sensors total per home. While you can grab these at the Google Store, you can also get them from Nest's website.